Adafruit ItsyBitsy nRF52840 Express Created by Kattni Rembor Last updated on 2020-01-27 03:54:22 PM UTC
Overview What's smaller than a Feather but larger than a Trinket? It's an Adafruit ItsyBitsy nRF52840 Express featuring the Nordic nRF52840 Bluetooth LE processor! Teensy & powerful, with an fast nRF52840 Cortex M4 processor running at 64 MHz and 1 MB of FLASH - this microcontroller board is perfect when you want something very compact, with a heap-load of memory and Bluetooth LE support This Itsy is your best option for tiny wireless connectivity - it can act as both a BLE central and peripheral, with sup
analog in). It's the same chip as the Feather nRF52840 (https://adafru.it/DLQ) but really really small. So it's great for those really compact builds. It even comes with 2MB of QSPI Flash built in, for data logging, file storage, or CircuitPython code. The most exciting part of the ItsyBitsy is that while we ship it with an Arduino IDE compatible demo, you can also install CircuitPython on board with only a few clicks. When you plug it in, it will show up as a very small disk drive with code.py on it.
Here are some of the updates you can look forward to when using ItsyBitsy nRF52: Same size, form-factor as the remaining ItsyBitsy mainboards (https://adafru.it/Ila) - with a similar but not identical pinout (there's no pins at the end of the board like most other Itsy's due to the radio antenna being there. Floating point support with Cortex M4 DSP instructions (https://adafru.it/ENz) 32-bit, 3.
Pinouts Power Pins The ItsyBitsy nRF52840 Express has BAT G USB on the top left, next to the micro USB port These pins are: BAT - battery input for an alternative power source to USB, the voltage can only be from 3.5V to 6VDC GND - Power/data ground USB - This is the same pin as the MicroUSB connector's 5V USB power pin. This should be used as an output to get 5V power from the USB port. Say if you need to power a bunch of NeoPixels or servos.
Adafruit LiIon/LiPoly Backpack Add-On for Pro Trinket/ItsyBitsy $4.95 IN STOCK Add To Cart In addition to the three standard power pins, the ItsyBitsy nRF52840 Express has a few more pins available for power sourcing: 3V - this is the regulated output from the onboard regulator. You can draw 500mA whether powered by USB or battery. EN - connected to the regulator enable, it will let you shut off power - when running on battery only. But at least you don't have to cut a trace or wire to your battery.
I2C pins on the nRF52840 require external pullup resistors to function, which are not present on the Adafruit nRF52840 Feather by default. You will need to supply external pullups to use these. All Adafruit I2C breakouts have appropriate pullups on them already, so this normally won't be an issue for you. Logic pins This is the general purpose I/O pin set for the microcontroller. All logic except for pin 5 is 3.3V output and input.
As part of the 'Express' series of boards, this ItsyBitsy is designed for use with CircuitPython. To make that easy, we have added two extra parts: a mini DotStar (RGB LED) and a 2 MB QSPI (Quad SPI) Flash chip. The DotStar is connected to pin #6 (clock) and #8 (data) in Arduino, so just use our DotStar library (https://adafru.it/zbD) and set it up as a single-LED strand on pins 6 & 8. The DotStar is powered by the 3.3V power supply but that hasn't shown to make a big difference in brightness or color.
Other Pins A tactile switch is provided for use in your projects, which is connected to P0.29 and is accessible in code as D4.
Arduino Support Setup You can install the Adafruit Bluefruit nRF52 BSP (Board Support Package) in two steps: nRF52 support requires at least Arduino IDE version 1.8.6! Please make sure you have an up to date version before proceeding with this guide! Please consult the FAQ section at the bottom of this page if you run into any problems installing or using this BSP! 1. BSP Installation Recommended: Installing the BSP via the Board Manager Download and install the Arduino IDE (https://adafru.
It will take up to a few minutes to finish installing the cross-compiling toolchain and tools associated with this BSP.
To keep up with Nordic's SoftDevice advances, you will likely need to update your bootloader if you are using the original nRF52832 based Bluefruit nRF52 Feather boards. Follow this link for instructions on how to do that This step ISN'T required for the newer nRF52840 Feather Express, which has a different bootloader entirely! https://adafru.it/Dsx https://adafru.
Arduino Examples Arduino Examples (https://adafru.it/Ilc) © Adafruit Industries https://learn.adafruit.
Arduino Bluefruit nRF52 API Arduino Bluefruit nRF52 API (https://adafru.it/Ild) © Adafruit Industries https://learn.adafruit.
nRF52 ADC The nRF52 family includes an adjustable 'successive-approximation ADC' which can be configured to convert data with up to 14-bit resolution (0..16383), and the reference voltage can be adjusted up to 3.6V internally. The default values for the ADC are 10-bit resolution (0..1023) with a 3.6V reference voltage, meaning every digit returned from the ADC = 3600mV/1024 = 3.515625mV. Analog Reference Voltage The internal reference voltage is 0.
int adcin = A5; int adcvalue = 0; float mv_per_lsb = 3600.0F/1024.0F; // 10-bit ADC with 3.6V input range void setup() { Serial.begin(115200); while ( !Serial ) delay(10); } // for nrf52840 with native usb void loop() { // Get a fresh ADC value adcvalue = analogRead(adcin); // Display the results Serial.print(adcvalue); Serial.print(" ["); Serial.print((float)adcvalue * mv_per_lsb); Serial.println(" mV]"); delay(100); } Advanced Example (12-bit, 3.
// Let the ADC settle delay(1); // Get the raw 12-bit, 0..3000mV ADC value raw = analogRead(vbat_pin); // Set the ADC back to the default settings analogReference(AR_DEFAULT); analogReadResolution(10); // Convert the raw value to compensated mv, taking the resistor// divider into account (providing the actual LIPO voltage) // ADC range is 0..3000mV and resolution is 12-bit (0..
FAQs NOTE: For FAQs relating to the BSP, see the dedicated BSP FAQ list (https://adafru.it/vnF). What are the differences between the nRF51 and nRF52 Bluefruit boards? Which one should I be using? The two board families take very different design approaches. All of the nRF51 based modules are based on an AT command set (over UART or SPI), and require two MCUs to run: the nRF51 hosting the AT command parser, and an external MCU sending AT style commands.
Can I run nRF51 Bluefruit sketches on the nRF52? No. The two board families are fundamentally different, and have entirely separate APIs and programming models. If you are migrating from the nRF51 to the nRF52, you will need to redesign your sketches to use the newer API, enabling you to build code that runs natively on the nRF52832 MCU. © Adafruit Industries https://learn.adafruit.
Can I use the nRF52 as a Central to connect to other BLE peripherals? The S132 Soft Device and the nRF52832 HW support Central mode, so yes this is possible. At this early development stage, though, there is only bare bones support for Central mode in the Adafruit nRF52 codebase, simply to test the HW and S132 and make sure that everything is configured properly. An example is provided of listening for incoming advertising packets, printing the packet contents and meta-data out to the Serial Monitor.
How are Arduino sketches executed on the nRF52? Can I do hard real time processing (bit-banging NeoPixels, Software Serial etc.)? In order to run Arduino code on the nRF52 at the same time as the low level Bluetooth Low Energy stack, the Bluefruit nRF52 Feather uses FreeRTOS as a task scheduler. The scheduler will automatically switch between tasks, assigning clock cycles to the highest priority task at a given moment.
Can I use GDB to debug my nRF52? You can, yes, but it will require a Segger J-Link (that's what we've tested against anyway, other options exist), and it's an advanced operation. But if you're asking about it, you probably know that.
Are there any other cross platform or free debugging options other than GDB? If you have a Segger J-Link, you can also use Segger's OZone debugger GUI to interact with the device, though check the license terms since there are usage restrictions depending on the J-Link module you have. You will need to connect your nRF52 to the J-Link via the SWD and SWCLK pins on the bottom of the PCB, or if you are OK with fine pitch soldering via the SWD header.
© Adafruit Industries https://learn.adafruit.
Next select the Attach to running program option in the top-left hand corner, or via the menu system, which will cause the debugger to connect to the nRF52 over SWD: At this point, you can click the PAUSE icon to stop program execution, and then analyze variables, or set breakpoints at appropriate locations in your program execution, and debug as you would with most other embedded IDEs! © Adafruit Industries https://learn.adafruit.
Clicking on the left-hand side of the text editor will set a breakpoint on line 69 in the image below, for example, and the selecting Debug > Reset > Reset & Run from the menu or icon will cause the board to reset, and you should stop at the breakpoint you set: You can experiment with adding some of the other debug windows and options via the View menu item, such as the Call Stack which will show you all of the functions that were called before arriving at the current breakpoint: © Adafruit Industries ht
Can I make two Bluefruit nRF52's talk to each other? Yes, by running one board in peripheral mode and one board in central mode, where the central will establish a connection with the peripheral board and you can communicate using BLE UART or a custom service. See the following Central BLE UART example to help you get started: https://github.com/adafruit/Adafruit_nRF52_Arduino/tree/master/libraries/Bluefruit52Lib/examples/Central © Adafruit Industries https://learn.adafruit.
On Linux I'm getting 'arm-none-eabi-g++: no such file or directory', even though 'arm-none-eabi-g++' exists in the path specified. What should I do? This is probably caused by a conflict between 32-bit and 64-bit versions of the compiler, libc and the IDE. The compiler uses 32-bit binaries, so you also need to have a 32-bit version of libc installed on your system (details). Try running the following commands from the command line to resolve this: © Adafruit Industries https://learn.adafruit.
sudo dpkg --add-architecture i386 sudo apt-get update whatapt-get shouldinstall I do when Arduino failed sudo libc6:i386 to upload sketch to my Feather ? If you get this error: Timed out waiting for acknowledgement from device. Failed to upgrade target. Error is: No data received on serial port. Not able to proceed. Traceback (most recent call last): File "nordicsemi\__main__.py", line 294, in serial File "nordicsemi\dfu\dfu.py", line 235, in dfu_send_images File "nordicsemi\dfu\dfu.
Do Feather/Metro nRF52832 and nRF52840 support BLE Mesh ? They all support BLE Mesh, but we don't provide Arduino library for Mesh. You need to write code based on Nordic sdk mesh. © Adafruit Industries https://learn.adafruit.
Unable to upload sketch/update bootloader with macOS If you get error similar to this: Arduino: 1.8.8 (Mac OS X), Board: "Adafruit Bluefruit nRF52832 Feather, 0.2.9 (s132 6.1.
© Adafruit Industries https://learn.adafruit.
What is CircuitPython? CircuitPython is a programming language designed to simplify experimenting and learning to program on low-cost microcontroller boards. It makes getting started easier than ever with no upfront desktop downloads needed. Once you get your board set up, open any text editor, and get started editing code. It's that simple. CircuitPython is based on Python Python is the fastest growing programming language. It's taught in schools and universities.
You're new to programming. CircuitPython is designed with education in mind. It's easy to start learning how to program and you get immediate feedback from the board. Easily update your code. Since your code lives on the disk drive, you can edit it whenever you like, you can also keep multiple files around for easy experimentation. The serial console and REPL. These allow for live feedback from your code and interactive programming. File storage.
CircuitPython CircuitPython (https://adafru.it/tB7) is a derivative of MicroPython (https://adafru.it/BeZ) designed to simplify experimentation and education on low-cost microcontrollers. It makes it easier than ever to get prototyping by requiring no upfront desktop software downloads. Simply copy and edit files on the CIRCUITPY drive to iterate. Set up CircuitPython Quick Start! Follow this quick step-by-step for super-fast Python power :) https://adafru.it/Ie7 https://adafru.
You will see a new disk drive appear called ITSY840BOOT. Drag the adafruit_circuitpython_etc.uf2 file to ITSY840BOOT. The LED will flash. Then, the ITSY840BOOT drive will disappear and a new disk drive called CIRCUITPY will appear. That's it, you're done! :) © Adafruit Industries https://learn.adafruit.
Installing Mu Editor Mu is a simple code editor that works with the Adafruit CircuitPython boards. It's written in Python and works on Windows, MacOS, Linux and Raspberry Pi. The serial console is built right in so you get immediate feedback from your board's serial output! Mu is our recommended editor - please use it (unless you are an experienced coder with a favorite editor already!) Download and Install Mu Download Mu from https://codewith.mu (https://adafru.it/Be6).
Mu attempts to auto-detect your board, so please plug in your CircuitPython device and make sure it shows up as a CIRCUITPY drive before starting Mu Now you're ready to code! Lets keep going.... © Adafruit Industries https://learn.adafruit.
Creating and Editing Code One of the best things about CircuitPython is how simple it is to get code up and running. In this section, we're going to cover how to create and edit your first CircuitPython program. To create and edit code, all you'll need is an editor. There are many options.
It will look like this - note that under the while True: line, the next four lines have spaces to indent them, but they're indented exactly the same amount. All other lines have no spaces before the text. Save this file as code.py on your CIRCUITPY drive. On each board you'll find a tiny red LED. It should now be blinking. Once per second © Adafruit Industries https://learn.adafruit.
Congratulations, you've just run your first CircuitPython program! Editing Code To edit code, open the code.py file on your CIRCUITPY drive into your editor. Make the desired changes to your code. Save the file. That's it! Your code changes are run as soon as the file is done saving. There's just one warning we have to give you before we continue... Don't Click Reset or Unplug! The CircuitPython code on your board detects when the files are changed or written and will automatically re-start your code.
vim (https://adafru.it/ek9) / vi safely writes all changes. But set up vim to not write swapfiles (https://adafru.it/ELO) (.swp files: temporary records of your edits) to CIRCUITPY. Run vim with vim -n , set the no swapfile option, or set the directory option to write swapfiles elsewhere. Otherwise the swapfile writes trigger restarts of your program. The PyCharm IDE (https://adafru.it/xNC) is safe if "Safe Write" is turned on in Settings->System Settings>Synchronization (true by default).
Back to Editing Code... Now! Let's try editing the program you added to your board. Open your code.py file into your editor. We'll make a simple change. Change the first 0.5 to 0.1 . The code should look like this: import board import digitalio import time led = digitalio.DigitalInOut(board.D13) led.direction = digitalio.Direction.OUTPUT while True: led.value = True time.sleep(0.1) led.value = False time.sleep(0.5) Leave the rest of the code as-is. Save your file.
Here is the original code again: import board import digitalio import time led = digitalio.DigitalInOut(board.D13) led.direction = digitalio.Direction.OUTPUT while True: led.value = True time.sleep(0.5) led.value = False time.sleep(0.5) Imports & Libraries Each CircuitPython program you run needs to have a lot of information to work. The reason CircuitPython is so simple to use is that most of that information is stored in other files and works in the background. These files are called libraries.
while True: led.value = True time.sleep(0.5) led.value = False time.sleep(0.5) First, we have led.value = True . This line tells the LED to turn on. On the next line, we have time.sleep(0.5) . This line is telling CircuitPython to pause running code for 0.5 seconds. Since this is between turning the led on and off, the led will be on for 0.5 seconds. The next two lines are similar. led.value = False tells the LED to turn off, and time.sleep(0.5) tells CircuitPython to pause for another 0.5 seconds.
More Changes We don't have to stop there! Let's keep going. Change the second 0.5 to 0.1 so it looks like this: while True: led.value = True time.sleep(0.1) led.value = False time.sleep(0.1) Now it blinks really fast! You decreased the both time that the code leaves the LED on and off! Now try increasing both of the 0.1 to 1 . Your LED will blink much more slowly because you've increased the amount of time that the LED is turned on and off.
Connecting to the Serial Console One of the staples of CircuitPython (and programming in general!) is something called a "print statement". This is a line you include in your code that causes your code to output text. A print statement in CircuitPython looks like this: print("Hello, world!") This line would result in: Hello, world! However, these print statements need somewhere to display.
Once in Mu, look for the Serial button in the menu and click it. Setting Permissions on Linux On Linux, if you see an error box something like the one below when you press the Serial button, you need to add yourself to a user group to have permission to connect to the serial console. On Ubuntu and Debian, add yourself to the dialout group by doing: sudo adduser $USER dialout After running the command above, reboot your machine to gain access to the group.
Interacting with the Serial Console Once you've successfully connected to the serial console, it's time to start using it. The code you wrote earlier has no output to the serial console. So, we're going to edit it to create some output. Open your code.py file into your editor, and include a print statement. You can print anything you like! Just include your phrase between the quotation marks inside the parentheses. For example: import board import digitalio import time led = digitalio.DigitalInOut(board.
the board reboots. Then you'll see your new change! The Traceback (most recent call last): is telling you the last thing your board was doing before you saved your file. This is normal behavior and will happen every time the board resets. This is really handy for troubleshooting. Let's introduce an error so we can see how it is used. Delete the e at the end of True from the line led.value = True so that it says led.value = Tru Save your file.
The Traceback (most recent call last): is telling you that the last thing it was able to run was line 10 in your code. The next line is your error: NameError: name 'Tru' is not defined . This error might not mean a lot to you, but combined with knowing the issue is on line 10, it gives you a great place to start! Go back to your code, and take a look at line 10. Obviously, you know what the problem is already. But if you didn't, you'd want to look at line 10 and see if you could figure it out.
The REPL The other feature of the serial connection is the Read-Evaluate-Print-Loop, or REPL. The REPL allows you to enter individual lines of code and have them run immediately. It's really handy if you're running into trouble with a particular program and can't figure out why. It's interactive so it's great for testing new ideas. To use the REPL, you first need to be connected to the serial console. Once that connection has been established, you'll want to press Ctrl + C.
If you have trouble getting to the >>> prompt, try pressing Ctrl + C a few more times. The first thing you get from the REPL is information about your board. This line tells you the version of CircuitPython you're using and when it was released. Next, it gives you the type of board you're using and the type of microcontroller the board uses. Each part of this may be different for your board depending on the versions you're working with. This is followed by the CircuitPython prompt.
Type help("modules") into the REPL next to the prompt, and press enter. This is a list of all the core libraries built into CircuitPython. We discussed how board contains all of the pins on the board that you can use in your code. From the REPL, you are able to see that list! Type import board into the REPL and press enter. It'll go to a new prompt.
This is a list of all of the pins on your board that are available for you to use in your code. Each board's list will differ slightly depending on the number of pins available. Do you see D13 ? That's the pin you used to blink the red LED! The REPL can also be used to run code. Be aware that any code you enter into the REPL isn't saved anywhere.
© Adafruit Industries https://learn.adafruit.
CircuitPython Libraries As we continue to develop CircuitPython and create new releases, we will stop supporting older releases. Visit https://circuitpython.org/downloads to download the latest version of CircuitPython for your board. You must download the CircuitPython Library Bundle that matches your version of CircuitPython. Please update CircuitPython and then visit https://circuitpython.org/libraries to download the latest Library Bundle.
We're constantly updating and improving our libraries, so we don't (at this time) ship our CircuitPython boards with the full library bundle. Instead, you can find example code in the guides for your board that depends on external libraries. Some of these libraries may be available from us at Adafruit, some may be written by community members! Either way, as you start to explore CircuitPython, you'll want to know how to get libraries on board.
Now open the lib folder. When you open the folder, you'll see a large number of mpy files and folders Example Files All example files from each library are now included in the bundles, as well as an examples-only bundle. These are included for two main reasons: Allow for quick testing of devices. Provide an example base of code, that is easily built upon for individualized purposes. Copying Libraries to Your Board First you'll want to create a lib folder on your CIRCUITPY drive.
This demonstration will only return an error if you do not have the required library loaded into the lib folder on your CIRCUITPY drive. Let's use a modified version of the blinky example. import board import time import simpleio led = simpleio.DigitalOut(board.D13) while True: led.value = True time.sleep(0.5) led.value = False time.sleep(0.5) Save this file. Nothing happens to your board. Let's check the serial console to see what's going on. We have an ImportError .
Library Install on Non-Express Boards If you have a Trinket M0 or Gemma M0, you'll want to follow the same steps in the example above to install libraries as you need them. You don't always need to wait for an ImportError as you probably know what library you added to your code. Simply open the lib folder you downloaded, find the library you need, and drag it to the lib folder on your CIRCUITPY drive.
Frequently Asked Questions These are some of the common questions regarding CircuitPython and CircuitPython microcontrollers. As we continue to develop CircuitPython and create new releases, we will stop supporting older releases. Visit https://circuitpython.org/downloads to download the latest version of CircuitPython for your board. You must download the CircuitPython Library Bundle that matches your version of CircuitPython. Please update CircuitPython and then visit https://circuitpython.
How do I connect to the Internet with CircuitPython? If you'd like to add WiFi support, check out our guide on ESP32/ESP8266 as a co-processor. © Adafruit Industries https://learn.adafruit.
Is there asyncio support in CircuitPython We do not have asyncio support in CircuitPython at this time © Adafruit Industries https://learn.adafruit.
My RGB NeoPixel/DotStar LED is blinking funny colors - what does it mean? The status LED can tell you what's going on with your CircuitPython board. Read more here for what the colors mean! © Adafruit Industries https://learn.adafruit.
What is a MemoryError ? Memory allocation errors happen when you're trying to store too much on the board. The CircuitPython microcontroller boards have a limited amount of memory available. You can have about 250 lines of code on the M0 Express boards. If you try to import too many libraries, a combination of large libraries, or run a program with too many lines of code, your code will fail to run and you will receive a MemoryError in the serial console (REPL).
It can because the memory gets fragmented differently depending on allocation order and the size of objects. Loading .mpy files uses less memory so its recommended to do that for files you aren't editing. How can I create my own .mpy files? You can make your own .mpy versions of files with mpy-cross . You can download the CircuitPython 2.x version of mpy-cross for your operating system from the CircuitPython Releases page (https://adafru.it/tBa) under the latest 2.x version.
Welcome to the Community! CircuitPython is a programming language that's super simple to get started with and great for learning. It runs on microcontrollers and works out of the box. You can plug it in and get started with any text editor. The best part? CircuitPython comes with an amazing, supportive community. Everyone is welcome! CircuitPython is Open Source. This means it's available for anyone to use, edit, copy and improve upon.
There are many different channels so you can choose the one best suited to your needs. Each channel is shown on Discord as "#channelname". There's the #projecthelp channel for assistance with your current project or help coming up with ideas for your next one. There's the #showandtell channel for showing off your newest creation. Don't be afraid to ask a question in any channel! If you're unsure, #general is a great place to start.
Be sure to include the steps you took to get to where you are. If it involves wiring, post a picture! If your code is giving you trouble, include your code in your post! These are great ways to make sure that there's enough information to help you with your issue. You might think you're just getting started, but you definitely know something that someone else doesn't.
When working with CircuitPython, you may find problems. If you find a bug, that's great! We love bugs! Posting a detailed issue to GitHub is an invaluable way to contribute to improving CircuitPython. Be sure to include the steps to replicate the issue as well as any other information you think is relevant. The more detail, the better! Testing new software is easy and incredibly helpful. Simply load the newest version of CircuitPython or a library onto your CircuitPython hardware, and use it.
Advanced Serial Console on Windows Windows 7 Driver If you're using Windows 7, use the link below to download the driver package. You will not need to install drivers on Mac, Linux or Windows 10. https://adafru.it/AB0 https://adafru.it/AB0 What's the COM? First, you'll want to find out which serial port your board is using. When you plug your board in to USB on your computer, it connects to a serial port. The port is like a door through which your board can communicate with your computer using USB.
Sometimes the item will refer to the name of the board. Other times it may be called something like USB Serial Device, as seen in the image above. Either way, there is a new (COM#) following the name. This is the port your board is using. Install Putty If you're using Windows, you'll need to download a terminal program. We're going to use PuTTY. The first thing to do is download the latest version of PuTTY (https://adafru.it/Bf1). You'll want to download the Windows installer file.
Once your settings are entered, you're ready to connect to the serial console. Click "Open" at the bottom of the window. A new window will open. If no code is running, the window will either be blank or will look like the window above. Now you're ready to see the results of your code. Great job! You've connected to the serial console! © Adafruit Industries https://learn.adafruit.
Advanced Serial Console on Mac and Linux Connecting to the serial console on Mac and Linux uses essentially the same process. Neither operating system needs drivers installed. On MacOSX, Terminal comes installed. On Linux, there are a variety such as gnome-terminal (called Terminal) or Konsole on KDE. What's the Port? First you'll want to find out which serial port your board is using. When you plug your board in to USB on your computer, it connects to a serial port.
Now, plug your board. Using Mac, type: ls /dev/tty.* This will show you the current serial connections, which will now include your board. Using Mac, a new listing has appeared called /dev/tty.usbmodem141441 . The tty.usbmodem141441 part of this listing is the name the example board is using. Yours will be called something similar. Using Linux, type: ls /dev/ttyACM* This will show you the current serial connections, which will now include your board. © Adafruit Industries https://learn.adafruit.
Using Linux, a new listing has appeared called /dev/ttyACM0 . The ttyACM0 part of this listing is the name the example board is using. Yours will be called something similar. Connect with screen Now that you know the name your board is using, you're ready connect to the serial console. We're going to use a command called screen . The screen command is included with MacOS. Linux users may need to install it using their package manager. To connect to the serial console, use Terminal.
Press enter to run the command. It will open in the same window. If no code is running, the window will be blank. Otherwise, you'll see the output of your code. Great job! You've connected to the serial console! Permissions on Linux If you try to run screen and it doesn't work, then you may be running into an issue with permissions. Linux keeps track of users and groups and what they are allowed to do and not do, like access the hardware associated with the serial connection for running screen .
The second way is to add yourself to the group associated with the hardware. To figure out what that group is, use the command ls -l as shown below. The group name is circled in red. Then use the command adduser to add yourself to that group. You need elevated privileges to do this, so you'll need to use sudo . In the example below, the group is adm and the user is ackbar. After you add yourself to the group, you'll need to logout and log back in, or in some cases, reboot your machine.
The examples above use screen , but you can also use other programs, such as putty or picocom , if you prefer. © Adafruit Industries https://learn.adafruit.
Uninstalling CircuitPython A lot of our boards can be used with multiple programming languages. For example, the Circuit Playground Express can be used with MakeCode, Code.org CS Discoveries, CircuitPython and Arduino.
Your MakeCode is now running and CircuitPython has been removed. Going forward you only have to single click the reset button Moving to Arduino If you want to change your firmware to Arduino, it's also pretty easy. Start by plugging in your board, and double-clicking reset until you get the green onboard LED(s) - just like with MakeCode Within Arduino IDE, select the matching board, say Circuit Playground Express Select the correct matching Port: © Adafruit Industries https://learn.adafruit.
Create a new simple Blink sketch example: // the setup function runs once when you press reset or power the board void setup() { // initialize digital pin 13 as an output.
Troubleshooting From time to time, you will run into issues when working with CircuitPython. Here are a few things you may encounter and how to resolve them. As we continue to develop CircuitPython and create new releases, we will stop supporting older releases. Visit https://circuitpython.org/downloads to download the latest version of CircuitPython for your board. You must download the CircuitPython Library Bundle that matches your version of CircuitPython.
and uninstall all the "Adafruit" driver programs. Windows 7 The latest version of the Adafruit Windows Drivers (version 2.0.0.0 or later) will fix the missing boardnameBOOT drive problem on Windows 7. To resolve this, first uninstall the old versions of the drivers: Unplug any boards. In Uninstall or Change a Program (Control Panel->Programs->Uninstall a program), uninstall everything named "Windows Driver Package - Adafruit Industries LLC ...". Now install the new 2.3.0.
Windows Explorer Locks Up When Accessing boardnameBOOT Drive On Windows, several third-party programs we know of can cause issues. The symptom is that you try to access the boardnameBOOT drive, and Windows or Windows Explorer seems to lock up. These programs are known to cause trouble: AIDA64: to fix, stop the program. This problem has been reported to AIDA64. They acquired hardware to test, and released a beta version that fixes the problem. This may have been incorporated into the latest release.
message. This applies to any kind of serial output whether it be error messages or print statements. So before you start trying to debug your problem on the hardware side, be sure to check that you haven't simply missed the serial messages due to serial output panel height.
that triggered the error on import . They are all available in the Adafruit bundle (https://adafru.it/y8E). Make sure to download a version with 2.0.0 or higher in the filename if you're using CircuitPython version 2.2.4, and the version with 3.0.0 or higher in the filename if you're using CircuitPython version 3.0. CIRCUITPY Drive Issues You may find that you can no longer save files to your CIRCUITPY drive. You may find that your CIRCUITPY stops showing up in your file explorer, or shows up as NO_NAME .
https://adafru.it/EVK https://adafru.it/EVK https://adafru.it/AdK https://adafru.it/AdK https://adafru.it/EoM https://adafru.it/EoM https://adafru.it/DjD https://adafru.it/DjD https://adafru.it/DBA https://adafru.it/DBA https://adafru.it/Eca https://adafru.it/Eca https://adafru.it/Gnc https://adafru.it/Gnc https://adafru.it/GAN https://adafru.it/GAN https://adafru.it/GAO https://adafru.it/GAO 2. Double-click the reset button on the board to bring up the boardnameBOOT drive. 3. Drag the erase .
Old Way: For Non-Express Boards with a UF2 bootloader (Gemma M0, Trinket M0): If you can't get to the REPL, or you're running a version of CircuitPython before 2.3.0, and you don't want to upgrade, you can do this. 1. Download the erase file: https://adafru.it/AdL https://adafru.it/AdL 2. 3. 4. 5. Double-click the reset button on the board to bring up the boardnameBOOT drive. Drag the erase .uf2 file to the boardnameBOOT drive.
Luckily you can disable some of the extra hidden files that Mac OSX adds by running a few commands to disable search indexing and create zero byte placeholders. Follow the steps below to maximize the amount of space available on OSX: Prevent & Remove Mac OSX Hidden Files First find the volume name for your board. With the board plugged in run this command in a terminal to list all the volumes: ls -l /Volumes Look for a volume with a name like CIRCUITPY (the default for CircuitPython).
cp -X foo.mpy /Volumes/CIRCUITPY (Replace foo.mpy with the name of the file you want to copy.) Or to copy a folder and all of its child files/folders use a command like: cp -rX folder_to_copy /Volumes/CIRCUITPY If you are copying to the lib folder, or another folder, make sure it exists before copying. # if lib does not exist, you'll create a file named lib ! cp -X foo.mpy /Volumes/CIRCUITPY/lib # This is safer, and will complain if a lib folder does not exist. cp -X foo.
Whoa! We have 13Ki more than before! This space can now be used for libraries and code! © Adafruit Industries https://learn.adafruit.
Getting Started with BLE and CircuitPython Guides Getting Started with CircuitPython and Bluetooth Low Energy (https://adafru.it/FxH) - Get started with CircuitPython, the Adafruit nRF52840 and the Bluefruit LE Connect app. BLE Light Switch with Feather nRF52840 and Crickit (https://adafru.it/Ile) - Control a robot finger from across the room to flip on and off the lights! Color Remote with Circuit Playground Bluefruit (https://adafru.
CircuitPython Essentials You've gone through the Welcome to CircuitPython guide (https://adafru.it/cpy-welcome). You've already gotten everything setup, and you've gotten CircuitPython running. Great! Now what? CircuitPython Essentials! There are a number of core modules built into CircuitPython and commonly used libraries available. This guide will introduce you to these and show you an example of how to use each one.
CircuitPython BuiltIns CircuitPython comes 'with the kitchen sink' - a lot of the things you know and love about classic Python 3 (sometimes called CPython) already work. There are a few things that don't but we'll try to keep this list updated as we add more capabilities! This is not an exhaustive list! It's simply some of the many features you can use. Thing That Are Built In and Work Flow Control All the usual if , elif , else , for , while work just as expected.
CircuitPython Digital In & Out The first part of interfacing with hardware is being able to manage digital inputs and outputs. With CircuitPython, it's super easy! This example shows how to use both a digital input and output. You can use a switch input with pullup resistor (built in) to control a digital output - the built in red LED. Copy and paste the code into code.py using your favorite editor, and save the file to run the demo.
DigitalInOut(board.D7) . To find the pin or pad suggested in the code, see the list below. For the boards that require wiring, wire up a switch (also known as a tactile switch, button or push-button), following the diagram for guidance. Press or slide the switch, and the onboard red LED will turn on and off. Note that on the M0/SAMD based CircuitPython boards, at least, you can also have internal pulldowns with Pull.DOWN and if you want to turn off the pullup/pulldown just assign switch.pull = None.
Gemma M0 D2 is an alligator-clip-friendly pad labeled both "D2" and "A1", shown connected to the blue wire, and is next to the USB micro port. D13 is located next to the "GND" label on the board, above the "On/Off" switch. Use alligator clips to connect your switch to your Gemma M0! Feather M0 Express and Feather M4 Express D5 is labeled "5" and connected to the blue wire on the board. D13 is labeled "#13" and is located next to the USB micro port.
Metro M0 Express and Metro M4 Express D2 is located near the top left corner, and is connected to the blue wire. D13 is labeled "L" and is located next to the USB micro port. Read the Docs For a more in-depth look at what digitalio can do, check out the DigitalInOut page in Read the Docs (https://adafru.it/C4c). © Adafruit Industries https://learn.adafruit.
CircuitPython Analog In This example shows you how you can read the analog voltage on the A1 pin on your board. Copy and paste the code into code.py using your favorite editor, and save the file to run the demo. # CircuitPython AnalogIn Demo import time import board from analogio import AnalogIn analog_in = AnalogIn(board.A1) def get_voltage(pin): return (pin.value * 3.3) / 65536 while True: print((get_voltage(analog_in),)) time.sleep(0.
Changing It Up By default the pins are floating so the voltages will vary. While connected to the serial console, try touching a wire from A1 to the GND pin or 3Vo pin to see the voltage change. You can also add a potentiometer to control the voltage changes. From the potentiometer to the board, connect the left pin to ground, the middle pin to A1, and the right pin to 3V.
Circuit Playground Express A1 is located on the right side of the board. There are multiple ground and 3V pads (pins). Your board has 7 analog pins that can be used for this purpose. For the full list, see the pinout page (https://adafru.it/AM9) on the main guide. Trinket M0 A1 is labeled as 2! It's located between "1~" and "3V" on the same side of the board as the little red LED. Ground is located on the opposite side of the board.
Gemma M0 A1 is located near the top of the board of the board to the left side of the USB Micro port. Ground is on the other side of the USB port from A1. 3V is located to the left side of the battery connector on the bottom of the board. Your board has 3 analog pins. For the full list, see the pinout page (https://adafru.it/AMa) on the main guide. Feather M0 Express and Feather M4 Express A1 is located along the edge opposite the battery connector. There are multiple ground pins.
ItsyBitsy M0 Express and ItsyBitsy M4 Express A1 is located in the middle of the board, near the "A" in "Adafruit". Ground is labled "G" and is located next to "BAT", near the USB Micro port. 3V is found on the opposite side of the USB port from Ground, next to RST. You have 6 analog pins you can use. For a full list, see the pinouts page (https://adafru.it/BMg) on the main guide. Metro M0 Express and Metro M4 Express A1 is located on the same side of the board as the barrel jack.
import time import board from analogio import AnalogIn analog_in = AnalogIn(board.A1) while True: print(analog_in.value) time.sleep(0.1) This works with any analog pin or input. Use the .value to read the raw value and utilise it in your code. © Adafruit Industries https://learn.adafruit.
CircuitPython Analog Out This example shows you how you can set the DAC (true analog output) on pin A0. A0 is the only true analog output on the M0 boards. No other pins do true analog output! Copy and paste the code into code.py using your favorite editor, and save the file. # CircuitPython IO demo - analog output import board from analogio import AnalogOut analog_out = AnalogOut(board.
Find the pin Use the diagrams below to find the A0 pin marked with a magenta arrow! Circuit Playground Express A0 is located between VOUT and A1 near the battery port. Trinket M0 A0 is labeled "1~" on Trinket! A0 is located between "0" and "2" towards the middle of the board on the same side as the red LED. © Adafruit Industries https://learn.adafruit.
Gemma M0 A0 is located in the middle of the right side of the board next to the On/Off switch. Feather M0 Express A0 is located between GND and A1 on the opposite side of the board from the battery connector, towards the end with the Reset button.
ItsyBitsy M0 Express A0 is located between VHI and A1, near the "A" in "Adafruit", and the pin pad has left and right white parenthesis markings around it. ItsyBitsy M4 Express A0 is located between VHI and A1, and the pin pad has left and right white parenthesis markings around it. Metro M0 Express A0 is between VIN and A1, and is located along the same side of the board as the barrel jack adapter towards the middle of the headers found on that side of the board. © Adafruit Industries https://learn.
Metro M4 Express A0 is between VIN and A1, and is located along the same side of the board as the barrel jack adapter towards the middle of the headers found on that side of the board. On the Metro M4 Express, there are TWO true analog outputs: A0 and A1. © Adafruit Industries https://learn.adafruit.
CircuitPython PWM Your board has pulseio support, which means you can PWM LEDs, control servos, beep piezos, and manage "pulse train" type devices like DHT22 and Infrared. Nearly every pin has PWM support! For example, all ATSAMD21 board have an A0 pin which is 'true' analog out and does not have PWM support. PWM with Fixed Frequency This example will show you how to use PWM to fade the little red LED on your board. Copy and paste the code into code.py using your favorite editor, and save the file.
To use with the Metro M4 Express, ItsyBitsy M4 Express or the Feather M4 Express, you must comment out the piezo = pulseio.PWMOut(board.A2, duty_cycle=0, frequency=440, variable_frequency=True) line and uncomment the piezo = pulseio.PWMOut(board.A1, duty_cycle=0, frequency=440, variable_frequency=True) line. A2 is not a supported PWM pin on the M4 boards! Remember: To "comment out" a line, put a # and a space before it. To "uncomment" a line, remove the # + space from the beginning of the line.
Wire it up Use the diagrams below to help you wire up your piezo. Attach one leg of the piezo to pin A2 on the M0 boards or A1 on the M4 boards, and the other leg to ground. It doesn't matter which leg is connected to which pin. They're interchangeable! Circuit Playground Express Use alligator clips to attach A2 and any one of the GND to different legs of the piezo.
Gemma M0 Use alligator clips to attach A2 and GND to different legs on the piezo. Gemma has PWM available on the following pins: A1, D2, RX, SCL, A2, D0, TX, SDA, L, D13, APA102_MOSI, APA102_SCK. There is NO PWM on: A0, D1. Feather M0 Express Use jumper wires to attach A2 and one of the two GND to different legs of the piezo. Feather M0 Express has PWM on the following pins: A2, A3, A4, SCK, MOSI, MISO, D0, RX, D1, TX, SDA, SCL, D5, D6, D9, D10, D11, D12, D13, NEOPIXEL. There is NO PWM on: A0, A1, A5.
ItsyBitsy M0 Express Use jumper wires to attach A2 and G to different legs of the piezo. ItsyBitsy M0 Express has PWM on the following pins: D0, RX, D1, TX, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11, D12, D13, L, A2, A3, A4, MOSI, MISO, SCK, SCL, SDA, APA102_MOSI, APA102_SCK. There is NO PWM on: A0, A1, A5. ItsyBitsy M4 Express Use jumper wires to attach A1 and G to different legs of the piezo. To use A1, comment out the current pin setup line, and uncomment the line labeled for the M4 boards.
Metro M4 Express Use jumper wires to connect A1 and any one of the GND to different legs on the piezo. To use A1, comment out the current pin setup line, and uncomment the line labeled for the M4 boards. See the details above! Metro M4 Express has PWM on: A1, A5, D0, RX, D1, TX, D2, D3, D4, D5, D6, D7, D8, D9, D10, D11, D12, D13, SDA, SCK, MOSI, MISO There is No PWM on: A0, A2, A3, A4, SCL, AREF, NEOPIXEL, LED_RX, LED_TX.
CircuitPython Servo In order to use servos, we take advantage of pulseio . Now, in theory, you could just use the raw pulseio calls to set the frequency to 50 Hz and then set the pulse widths. But we would rather make it a little more elegant and easy! So, instead we will use adafruit_motor which manages servos for you quite nicely! adafruit_motor is a library so be sure to grab it from the library bundle if you have not yet (https://adafru.
For Gemma, use jumper wire alligator clips to connect the ground wire to GND, the power wire to VOUT, and the signal wire to A2. For Circuit Playground Express and Circuit Playground Bluefruit, use jumper wire alligator clips to connect the ground wire to GND, the power wire to VOUT, and the signal wire to A2. For boards like Feather M0 Express, ItsyBitsy M0 Express and Metro M0 Express, connect the ground wire to any GND, the power wire to USB or 5V, and the signal wire to A2.
For the Metro M4 Express, ItsyBitsy M4 Express and the Feather M4 Express, connect the ground wire to any G or GND, the power wire to USB or 5V, and the signal wire to A1. Standard Servo Code Here's an example that will sweep a servo connected to pin A2 from 0 degrees to 180 degrees (-90 to 90 degrees) and back: import time import board import pulseio from adafruit_motor import servo # create a PWMOut object on Pin A2. pwm = pulseio.PWMOut(board.
# Continuous Servo Test Program for CircuitPython import time import board import pulseio from adafruit_motor import servo # create a PWMOut object on Pin A2. pwm = pulseio.PWMOut(board.A2, frequency=50) # Create a servo object, my_servo. my_servo = servo.ContinuousServo(pwm) while True: print("forward") my_servo.throttle time.sleep(2.0) print("stop") my_servo.throttle time.sleep(2.0) print("reverse") my_servo.throttle time.sleep(2.0) print("stop") my_servo.throttle time.sleep(4.0) = 1.0 = 0.0 = -1.
CircuitPython Internal RGB LED Every board has a built in RGB LED. You can use CircuitPython to control the color and brightness of this LED. There are two different types of internal RGB LEDs: DotStar (https://adafru.it/kDg) and NeoPixel (https://adafru.it/Bej). This section covers both and explains which boards have which LED. The first example will show you how to change the color and brightness of the internal RGB LED. Copy and paste the code into code.py using your favorite editor, and save the file.
single onboard LED, the last thing we do is tell it that there's only 1 LED! Trinket M0, Gemma M0, ItsyBitsy M0 Express, and ItsyBitsy M4 Express each have an onboard Dotstar LED, so no changes are needed to the initial version of the example. Feather M0 Express, Feather M4 Express, Metro M0 Express, Metro M4 Express, and Circuit Playground Express each have an onboard NeoPixel LED, so you must comment out import adafruit_dotstar and led = adafruit_dotstar.DotStar(board.APA102_SCK, board.
Try changing the numbers in the tuples to change your LED to any color of the rainbow. Or, you can add more lines with different color tuples to add more colors to the sequence. Always add the time.sleep() , but try changing the amount of time to create different cycle animations! Making Rainbows (Because Who Doesn't Love 'Em!) Coding a rainbow effect involves a little math and a helper function called wheel . For details about how wheel works, see this explanation here (https://adafru.
The last example shows how to do a rainbow animation on the internal RGB LED. Copy and paste the code into code.py using your favorite editor, and save the file. Remember to comment and uncomment the right lines for the board you're using, as explained above (https://adafru.it/Bel). import time import board # For Trinket M0, Gemma M0, ItsyBitsy M0 Express and ItsyBitsy M4 Express import adafruit_dotstar led = adafruit_dotstar.DotStar(board.APA102_SCK, board.
led = neopixel.NeoPixel(board.NEOPIXEL, 1) to 10 so it reads: led = neopixel.NeoPixel(board.NEOPIXEL, 10) . This tells the code to look for 10 LEDs instead of only 1. Now save the code and watch the rainbow go! You can make the same 1 to 10 change to the previous examples as well, and use led.fill to light up all the LEDs in the colors you chose! For more details, check out the NeoPixel section of the CPX guide (https://adafru.it/Bem)! © Adafruit Industries https://learn.adafruit.
CircuitPython NeoPixel NeoPixels are a revolutionary and ultra-popular way to add lights and color to your project. These stranded RGB lights have the controller inside the LED, so you just push the RGB data and the LEDs do all the work for you. They're a perfect match for CircuitPython! You can drive 300 NeoPixel LEDs with brightness control (set brightness=1.0 in object creation) and 1000 LEDs without. That's because to adjust the brightness we have to dynamically recreate the data-stream each write.
If the power to the NeoPixels is greater than 5.5V you may have some difficulty driving some strips, in which case you may need to lower the voltage to 4.5-5V or use a level shifter. Do not use the VIN pin directly on Metro M0 Express or Metro M4 Express! The voltage can reach 9V and this can destroy your NeoPixels! Note that the wire ordering on your NeoPixel strip or shape may not exactly match the diagram above.
pixels[i] = color time.sleep(wait) pixels.show() time.sleep(0.5) def rainbow_cycle(wait): for j in range(255): for i in range(num_pixels): rc_index = (i * 256 // num_pixels) + j pixels[i] = wheel(rc_index & 255) pixels.show() time.sleep(wait) RED = (255, 0, 0) YELLOW = (255, 150, 0) GREEN = (0, 255, 0) CYAN = (0, 255, 255) BLUE = (0, 0, 255) PURPLE = (180, 0, 255) while True: pixels.fill(RED) pixels.show() # Increase or decrease to change the speed of the solid color change. time.sleep(1) pixels.
By default, auto_write=True , meaning any changes you make to your pixels will be sent automatically. Since True is the default, if you use that setting, you don't need to include it in your LED object at all. We've chosen to set auto_write=False . If you set auto_write=False , you must include pixels.show() each time you'd like to send data to your pixels.
pixel_pin = board.A1 num_pixels = 8 pixels = neopixel.NeoPixel(pixel_pin, num_pixels, brightness=0.3, auto_write=False, pixel_order=(1, 0, 2, 3)) def wheel(pos): # Input a value 0 to 255 to get a color value. # The colours are a transition r - g - b - back to r.
color_chase(GREEN, 0.1) color_chase(CYAN, 0.1) color_chase(BLUE, 0.1) color_chase(PURPLE, 0.1) rainbow_cycle(0) # Increase the number to slow down the rainbow Read the Docs For a more in depth look at what neopixel can do, check out NeoPixel on Read the Docs (https://adafru.it/C5m). © Adafruit Industries https://learn.adafruit.
CircuitPython DotStar DotStars use two wires, unlike NeoPixel's one wire. They're very similar but you can write to DotStars much faster with hardware SPI and they have a faster PWM cycle so they are better for light painting. Any pins can be used but if the two pins can form a hardware SPI port, the library will automatically switch over to hardware SPI. If you use hardware SPI then you'll get 4 MHz clock rate (that would mean updating a 64 pixel strand in about 500uS - that's 0.0005 seconds).
Note that the wire ordering on your DotStar strip or shape may not exactly match the diagram above. Check the markings to verify which pin is DIN, CIN, 5V and GND The Code This example includes multiple visual effects. Copy and paste the code into code.py using your favorite editor, and save the file. # CircuitPython demo - Dotstar import time import adafruit_dotstar import board num_pixels = 30 pixels = adafruit_dotstar.DotStar(board.A1, board.A2, num_pixels, brightness=0.
pixels.show() time.sleep(wait) pixels[::2] = [YELLOW] * (num_pixels // 2) pixels.show() time.sleep(wait) pixels[1::2] = [GREEN] * (num_pixels // 2) pixels.show() time.sleep(wait) pixels[::2] = [TEAL] * (num_pixels // 2) pixels.show() time.sleep(wait) pixels[1::2] = [CYAN] * (num_pixels // 2) pixels.show() time.sleep(wait) pixels[::2] = [BLUE] * (num_pixels // 2) pixels.show() time.sleep(wait) pixels[1::2] = [PURPLE] * (num_pixels // 2) pixels.show() time.
ORANGE = (255, 40, 0) GREEN = (0, 255, 0) TEAL = (0, 255, 120) CYAN = (0, 255, 255) BLUE = (0, 0, 255) PURPLE = (180, 0, 255) MAGENTA = (255, 0, 20) WHITE = (255, 255, 255) while True: # Change this number to change how long it stays on each solid color. color_fill(RED, 0.5) color_fill(YELLOW, 0.5) color_fill(ORANGE, 0.5) color_fill(GREEN, 0.5) color_fill(TEAL, 0.5) color_fill(CYAN, 0.5) color_fill(BLUE, 0.5) color_fill(PURPLE, 0.5) color_fill(MAGENTA, 0.5) color_fill(WHITE, 0.
set auto_write=False . If you set auto_write=False , you must include pixels.show() each time you'd like to send data to your pixels. This makes your code more complicated, but it can make your LED animations faster! DotStar Helpers We've included a few helper functions to create the super fun visual effects found in this code. First is wheel() which we just learned with the Internal RGB LED (https://adafru.it/Bel).
import board import busio def is_hardware_spi(clock_pin, data_pin): try: p = busio.SPI(clock_pin, data_pin) p.deinit() return True except ValueError: return False # Provide the two pins you intend to use. if is_hardware_spi(board.A1, board.A2): print("This pin combination is hardware SPI!") else: print("This pin combination isn't hardware SPI.") Read the Docs For a more in depth look at what dotstar can do, check out DotStar on Read the Docs (https://adafru.it/C4d). © Adafruit Industries https://learn.
CircuitPython UART Serial In addition to the USB-serial connection you use for the REPL, there is also a hardware UART you can use. This is handy to talk to UART devices like GPSs, some sensors, or other microcontrollers! This quick-start example shows how you can create a UART device for communicating with hardware serial devices. To use this example, you'll need something to generate the UART data. We've used a GPS! Note that the GPS will give you UART data without getting a fix on your location.
The data that is returned is in a byte array, if you want to convert it to a string, you can use this handy line of code which will run chr() on each byte: datastr = ''.join([chr(b) for b in data]) # convert bytearray to string Your results will look something like this: For more information about the data you're reading and the Ultimate GPS, check out the Ultimate GPS guide: https://learn.adafruit.com/adafruit-ultimate-gps Wire It Up You'll need a couple of things to connect the GPS to your board.
Check out the list below for a diagram of your specific board! Watch out! A common mixup with UART serial is that RX on one board connects to TX on the other! However, sometimes boards have RX labeled TX and vice versa. So, you'll want to start with RX connected to TX, but if that doesn't work, try the other way around! Circuit Playground Express and Circuit Playground Bluefruit Connect 3.3v on your CPX to 3.3v on your GPS. Connect GND on your CPX to GND on your GPS.
Gemma M0 Connect 3vo on the Gemma to 3.3v on the GPS. Connect GND on the Gemma to GND on the GPS. Connect A1/D2 on the Gemma to TX on the GPS. Connect A2/D0 on the Gemma to RX on the GPS. Feather M0 Express and Feather M4 Express Connect USB on the Feather to VIN on the GPS. Connect GND on the Feather to GND on the GPS. Connect RX on the Feather to TX on the GPS. Connect TX on the Feather to RX on the GPS.
Metro M0 Express and Metro M4 Express Connect 5V on the Metro to VIN on the GPS. Connect GND on the Metro to GND on the GPS. Connect RX/D0 on the Metro to TX on the GPS. Connect TX/D1 on the Metro to RX on the GPS. Where's my UART? On the SAMD21, we have the flexibility of using a wide range of pins for UART. Compare this to some chips like the ESP8266 with fixed UART pins. The good news is you can use many but not all pins.
import board import busio from microcontroller import Pin def is_hardware_uart(tx, rx): try: p = busio.UART(tx, rx) p.deinit() return True except ValueError: return False def get_unique_pins(): exclude = ['NEOPIXEL', 'APA102_MOSI', 'APA102_SCK'] pins = [pin for pin in [ getattr(board, p) for p in dir(board) if p not in exclude] if isinstance(pin, Pin)] unique = [] for p in pins: if p not in unique: unique.
CircuitPython I2C I2C is a 2-wire protocol for communicating with simple sensors and devices, meaning it uses two connections for transmitting and receiving data. There are many I2C devices available and they're really easy to use with CircuitPython. We have libraries available for many I2C devices in the library bundle (https://adafru.it/uap).
Circuit Playground Express and Circuit Playground Bluefruit Connect 3.3v on your CPX to 3.3v on your TSL2561. Connect GND on your CPX to GND on your TSL2561. Connect SCL/A4 on your CPX to SCL on your TSL2561. Connect SDL/A5 on your CPX to SDA on your TSL2561. Trinket M0 Connect USB on the Trinket to VIN on the TSL2561. Connect Gnd on the Trinket to GND on the TSL2561. Connect D2 on the Trinket to SCL on the TSL2561. Connect D0 on the Trinket to SDA on the TSL2561.
Feather M0 Express and Feather M4 Express Connect USB on the Feather to VIN on the TSL2561. Connect GND on the Feather to GND on the TSL2561. Connect SCL on the Feather to SCL on the TSL2561. Connect SDA on the Feather to SDA on the TSL2561. ItsyBitsy M0 Express and ItsyBitsy M4 Express Connect USB on the ItsyBitsy to VIN on the TSL2561 Connect G on the ItsyBitsy to GND on the TSL2561. Connect SCL on the ItsyBitsy to SCL on the TSL2561. Connect SDA on the ItsyBitsy to SDA on the TSL2561.
Metro M0 Express and Metro M4 Express Connect 5V on the Metro to VIN on the TSL2561. Connect GND on the Metro to GND on the TSL2561. Connect SCL on the Metro to SCL on the TSL2561. Connect SDA on the Metro to SDA on the TSL2561. Find Your Sensor The first thing you'll want to do after getting the sensor wired up, is make sure it's wired correctly. We're going to do an I2C scan to see if the board is detected, and if it is, print out its I2C address. Copy and paste the code into code.
i2c.scan()] . Open the serial console to see the results! The code prints out an array of addresses. We've connected the TSL2561 which has a 7-bit I2C address of 0x39. The result for this sensor is I2C addresses found: ['0x39'] . If no addresses are returned, refer back to the wiring diagrams to make sure you've wired up your sensor correctly. I2C Sensor Data Now we know for certain that our sensor is connected and ready to go.
Where's my I2C? On the SAMD21, SAMD51 and nRF52840, we have the flexibility of using a wide range of pins for I2C. On the nRF52840, any pin can be used for I2C! Some chips, like the ESP8266, require using bitbangio, but can also use any pins for I2C. There's some other chips that may have fixed I2C pin. The good news is you can use many but not all pins. Given the large number of SAMD boards we have, its impossible to guarantee anything other than the labeled 'SDA' and 'SCL'.
import board import busio from microcontroller import Pin def is_hardware_I2C(scl, sda): try: p = busio.I2C(scl, sda) p.deinit() return True except ValueError: return False except RuntimeError: return True def get_unique_pins(): exclude = ['NEOPIXEL', 'APA102_MOSI', 'APA102_SCK'] pins = [pin for pin in [ getattr(board, p) for p in dir(board) if p not in exclude] if isinstance(pin, Pin)] unique = [] for p in pins: if p not in unique: unique.
CircuitPython HID Keyboard and Mouse These examples have been updated for version 4+ of the CircuitPython HID library. On some boards, such as the CircuitPlayground Express, this library is built into CircuitPython. So, please use the latest version of CircuitPython with these examples. (At least 5.0.0-beta.3) One of the things we baked into CircuitPython is 'HID' (Human Interface Device) control - that means keyboard and mouse capabilities.
key_pin = digitalio.DigitalInOut(pin) key_pin.direction = digitalio.Direction.INPUT key_pin.pull = digitalio.Pull.UP key_pin_array.append(key_pin) led = digitalio.DigitalInOut(board.D13) led.direction = digitalio.Direction.OUTPUT print("Waiting for key pin...") while True: # Check each pin for key_pin in key_pin_array: if not key_pin.value: # Is it grounded? i = key_pin_array.index(key_pin) print("Pin #%d is grounded." % i) # Turn on the red LED led.value = True while not key_pin.
First, we assign some variables for later use. We create three arrays assigned to variables: keypress_pins , key_pin_array , and keys_pressed . The first is the pins we're going to use. The second is empty because we're going to fill it later. The third is what we would like our "keyboard" to output - in this case the letter "A" and the phrase, "Hello world!". We create our last variable assigned to control_key which allows us to later apply the shift key to our keypress.
select.direction = digitalio.Direction.INPUT select.pull = digitalio.Pull.UP pot_min = 0.00 pot_max = 3.29 step = (pot_max - pot_min) / 20.0 def get_voltage(pin): return (pin.value * 3.3) / 65536 def steps(axis): """ Maps the potentiometer voltage range to 0-20 """ return round((axis - pot_min) / step) while True: x = get_voltage(x_axis) y = get_voltage(y_axis) if select.value is False: mouse.click(Mouse.LEFT_BUTTON) time.sleep(0.2) # Debounce delay if steps(x) > 11.0: # print(steps(x)) mouse.
Connect Yout on the joystick to pin A1 on your board. Connect Sel on the joystick to pin A2 on your board. Remember, Trinket's pins are labeled differently. Check the Trinket Pinouts page (https://adafru.it/AMd) to verify your wiring. To use this demo, simply move the joystick around. The mouse will move slowly if you move the joystick a little off center, and more quickly if you move it as far as it goes. Press down on the joystick to click the mouse. Awesome! Now let's take a look at the code.
the joystick because the joystick sits at the center of this range, 1.66, and the + and - of each axis is above and below this number. Since we need to have thresholds in our code, we're going to map that range of 0-3.29 to while numbers between 0-20.0 using this helper function. That way we can simplify our code and use larger ranges for our thresholds instead of trying to figure out tiny decimal number changes. Main Loop First we assign x and y to read the voltages from x_axis and y_axis .
CircuitPython Storage CircuitPython boards show up as as USB drive, allowing you to edit code directly on the board. You've been doing this for a while. By now, maybe you've wondered, "Can I write data from CircuitPython to the storage drive to act as a datalogger?" The answer is yes! However, it is a little tricky. You need to add some special code to boot.py, not just code.py.
import time import board import digitalio import microcontroller led = digitalio.DigitalInOut(board.D13) led.switch_to_output() try: with open("/temperature.txt", "a") as fp: while True: temp = microcontroller.cpu.temperature # do the C-to-F conversion here if you would like fp.write('{0:f}\n'.format(temp)) fp.flush() led.value = not led.value time.sleep(1) except OSError as e: delay = 0.5 if e.args[0] == 28: delay = 0.25 while True: led.value = not led.value time.
boot.py only runs on first boot of the device, not if you re-load the serial console with ctrl+D or if you save a file. You must EJECT the USB drive, then physically press the reset button! Once you copied the files to your board, eject it and unplug it from your computer. If you're using your Circuit Playground Express, all you have to do is make sure the switch is to the right. Otherwise, use alligator clips or jumper wires to connect the chosen pin to ground.
This file gets updated once per second, but you won't see data come in live. Instead, when you're ready to grab the data, eject and unplug your board. For CPX, move the switch to the left, otherwise remove the wire connecting the pin to ground. Now it will be possible for you to write to the filesystem from your computer again, but it will not be logging data. We have a more detailed guide on this project available here: CPU Temperature Logging with CircuitPython. (https://adafru.
CircuitPython CPU Temp There is a CPU temperature sensor built into every ATSAMD21, ATSAMD51 and nRF52840 chips. CircuitPython makes it really simple to read the data from this sensor. This works on the Adafruit CircuitPython boards it's built into the microcontroller used for these boards. The data is read using two simple commands. We're going to enter them in the REPL. Plug in your board, connect to the serial console (https://adafru.it/Bec), and enter the REPL (https://adafru.it/Awz).
CircuitPython Expectations As we continue to develop CircuitPython and create new releases, we will stop supporting older releases. Visit https://circuitpython.org/downloads to download the latest version of CircuitPython for your board. You must download the CircuitPython Library Bundle that matches your version of CircuitPython. Please update CircuitPython and then visit https://circuitpython.org/libraries to download the latest Library Bundle.
CircuitPython and your code. This means that we're able to include more functionality in CircuitPython and you're able to do more with your code on an Express board than you would on a non-Express board. Express boards include Circuit Playground Express, ItsyBitsy M0 Express, Feather M0 Express, Metro M0 Express and Metro M4 Express. Non-Express boards include Trinket M0, Gemma M0, Feather M0 Basic, and other non-Express Feather M0 variants.
accuracy is about +/-1.7e-38, though numbers as small as +/-5.6e-45 can be represented with reduced accuracy. CircuitPython's floats have 8 bits of exponent and 22 bits of mantissa (not 24 like regular single precision floating point), which is about five or six decimal digits of precision. Differences between MicroPython and Python For a more detailed list of the differences between CircuitPython and Python, you can look at the MicroPython documentation.
Software Resources To help you get your Bluefruit LE module talking to other Central devices, we've put together a number of open source tools for most of the major platforms supporting Bluetooth Low Energy. Bluefruit LE Client Apps and Libraries Adafruit has put together the following mobile or desktop apps and libraries to make it as easy as possible to get your Bluefruit LE module talking to your mobile device or laptop, with full source available where possible: Bluefruit LE Connect (https://adafru.
Bluefruit LE Connect for OS X (https://adafru.it/o9F) (Swift) This OS X desktop application is based on the same V2.x codebase as the iOS app, and gives you access to BLE UART, basic Pin I/O and OTA DFU firmware updates from the convenience of your laptop or mac. This is a great choice for logging sensor data locally and exporting it as a CSV, JSON or XML file for parsing in another application, and uses the native hardware on your computer so no BLE dongle is required on any recent mac.
$ ./bluefruit bluefruit v0.3 Usage: bluefruit [options...] Commands: Scan peripherals: Automatic update: Custom firmware: Show this screen: Show version: scan update [--enable-beta] [--uuid ] dfu --hex [--init ] [--uuid ] --help --version Options: --uuid If present the peripheral with that uuid is used.
in early BETA and drops the connection and takes more care to work with). This app allows you to collect sensor data or perform many of the same functionality offered by the mobile Bluefruit LE Connect apps, but on the desktop. The app is still in BETA, but full source (https://adafru.it/ijE) is available in addition to the easy to use pre-compiled binaries (https://adafru.it/ijB). Bluefruit LE Python Wrapper (https://adafru.
This command line tool is a python-based wrapper for programming ARM MCUs using either aSegger JLink (https://adafru.it/fYU) or an STLink/V2 (https://adafru.it/ijF). You can use it to reflash your Bluefruit LE module using the latest firmware from the Bluefruit LE firmware repo (https://adafru.it/edX). Details on how to use the tool are available in the readme.md file on the main Adafruit_Adalink (https://adafru.it/fPq) repo on Github.
$ python flash.py --jtag=jlink --board=blefriend32 --softdevice=8.0.0 --bootloader=2 --firmware=0.6.7 jtag : jlink softdevice : 8.0.0 bootloader : 2 board : blefriend32 firmware : 0.6.7 Writing Softdevice + DFU bootloader + Application to flash memory adalink -v nrf51822 --programmer jlink --wipe --program-hex "Adafruit_BluefruitLE_Firmware/softdevice/s110_nrf51_8.0.0_softdevice.hex" --program-hex "Adafruit_BluefruitLE_Firmware/bootloader/bootloader_0002.hex" --program-hex "Adafruit_BluefruitLE_Firmware/0.
Downloads Files: Adafruit_nRF52_Arduino (https://adafru.it/vaF): The core code for this device (hosted on Github) nRF52 Example Sketches (https://adafru.it/vaK): Browse the example code from the core repo on Github Fritzing object in the Adafruit Fritzing Library (https://adafru.it/ImA) EagleCAD PCB files on GitHub (https://adafru.it/IBX) 3D Models on GitHub (https://adafru.it/ItD) Module Details The Bluefruit nRF52840 Feather Express uses the MDBT50Q module from Raytac.
Board Design The board files are available on Github (https://adafru.it/ImB), and the board has the following physical layout: © Adafruit Industries https://learn.adafruit.
© Adafruit Industries Last Updated: 2020-01-27 03:54:22 PM UTC Page 179 of 179
