Adafruit Feather M0 Basic Proto Created by lady ada Last updated on 2018-01-18 05:33:35 AM UTC
Guide Contents Guide Contents Overview Pinouts Power Pins Logic pins Other Pins! Assembly Header Options! Soldering in Plain Headers 2 4 8 9 9 10 12 12 15 Prepare the header strip: Add the breakout board: And Solder! 15 16 16 Soldering on Female Header Tape In Place Flip & Tack Solder And Solder! 18 18 20 Power Management Battery + USB Power Power supplies Measuring Battery ENable pin Arduino IDE Setup 22 22 23 23 24 25 https://adafruit.github.io/arduino-board-index/package_adafruit_index.
Floating Point Conversion How Much RAM Available? Storing data in FLASH Feather HELP! 37 37 37 38 My Feather stopped working when I unplugged the USB! 38 My Feather never shows up as a COM or Serial port in the Arduino IDE 38 Ack! I "did something" and now when I plug in the Feather, it doesn't show up as a device anymore so I cant upload to it or fix it...
Overview Feather is the new development board from Adafruit, and like it's namesake it is thin, light, and lets you fly! We designed Feather to be a new standard for portable microcontroller cores. At the Feather M0's heart is an ATSAMD21G18 ARM Cortex M0 processor, clocked at 48 MHz and at 3.3V logic, the same one used in the new Arduino Zero.
To make it easy to use for portable projects, we added a connector for any of our 3.7V Lithium polymer batteries and built in battery charging. You don't need a battery, it will run just fine straight from the micro USB connector. But, if you do have a battery, you can take it on the go, then plug in the USB to recharge. The Feather will automatically switch over to USB power when its available.
Here's some handy specs! Measures 2.0" x 0.9" x 0.28" (51mm x 23mm x 8mm) without headers soldered in Light as a (large?) feather - 4.6 grams ATSAMD21G18 @ 48MHz with 3.3V logic/power 256KB of FLASH + 32KB of RAM 32.768 KHz crystal for clock generation & RTC 3.
Comes fully assembled and tested, with a USB bootloader that lets you quickly use it with the Arduino IDE. We also toss in some header so you can solder it in and plug into a solderless breadboard. Lipoly battery and USB cable not included (but we do have lots of options in the shop if you'd like!) © Adafruit Industries https://learn.adafruit.
Pinouts The Feather M0 Basic is chock-full of microcontroller goodness. There's also a lot of pins and ports. We'll take you a tour of them now! © Adafruit Industries https://learn.adafruit.
Power Pins GND - this is the common ground for all power and logic BAT - this is the positive voltage to/from the JST jack for the optional Lipoly battery USB - this is the positive voltage to/from the micro USB jack if connected EN - this is the 3.3V regulator's enable pin. It's pulled up, so connect to ground to disable the 3.3V regulator 3V - this is the output from the 3.3V regulator, it can supply 500mA peak Logic pins This is the general purpose I/O pin set for the microcontroller. All logic is 3.
#5 - GPIO #5 #6 - GPIO #6 #9 - GPIO #9, also analog input A7. This analog input is connected to a voltage divider for the lipoly battery so be aware that this pin naturally 'sits' at around 2VDC due to the resistor divider #10 - GPIO #10 #11 - GPIO #11 #12 - GPIO #12 #13 - GPIO #13 and is connected to the red LED next to the USB jack A0 - This pin is analog input A0 but is also an analog output due to having a DAC (digital-to-analog converter). You can set the raw voltage to anything from 0 to 3.
© Adafruit Industries https://learn.adafruit.
Assembly We ship Feathers fully tested but without headers attached - this gives you the most flexibility on choosing how to use and configure your Feather Header Options! Before you go gung-ho on soldering, there's a few options to consider! The first option is soldering in plain male headers, this lets you plug in the Feather into a solderless breadboard © Adafruit Industries https://learn.adafruit.
Another option is to go with socket female headers. This won't let you plug the Feather into a breadboard but it will let you attach featherwings very easily © Adafruit Industries https://learn.adafruit.
We also have 'slim' versions of the female headers, that are a little shorter and give a more compact shape © Adafruit Industries https://learn.adafruit.
Finally, there's the "Stacking Header" option. This one is sort of the best-of-both-worlds. You get the ability to plug into a solderless breadboard and plug a featherwing on top. But its a little bulky Soldering in Plain Headers © Adafruit Industries https://learn.adafruit.
Prepare the header strip: Cut the strip to length if necessary. It will be easier to solder if you insert it into a breadboard - long pins down © Adafruit Industries https://learn.adafruit.
Add the breakout board: Place the breakout board over the pins so that the short pins poke through the breakout pads And Solder! Be sure to solder all pins for reliable electrical contact. (For tips on soldering, be sure to check out our Guide to Excellent Soldering (https://adafru.it/aTk)). © Adafruit Industries https://learn.adafruit.
Solder the other strip as well. © Adafruit Industries https://learn.adafruit.
You're done! Check your solder joints visually and continue onto the next steps Soldering on Female Header Tape In Place For sockets you'll want to tape them in place so when you flip over the board they don't fall out © Adafruit Industries https://learn.adafruit.
Flip & Tack Solder After flipping over, solder one or two points on each strip, to 'tack' the header in place © Adafruit Industries https://learn.adafruit.
And Solder! Be sure to solder all pins for reliable electrical contact. (For tips on soldering, be sure to check out our Guide to Excellent Soldering (https://adafru.it/aTk)). © Adafruit Industries https://learn.adafruit.
You're done! Check your solder joints visually and continue onto the next steps © Adafruit Industries https://learn.adafruit.
Power Management Battery + USB Power We wanted to make the Feather easy to power both when connected to a computer as well as via battery. There's two ways to power a Feather. You can connect with a MicroUSB cable (just plug into the jack) and the Feather will regulate the 5V USB down to 3.3V. You can also connect a 4.2/3.7V Lithium Polymer (Lipo/Lipoly) or Lithium Ion (LiIon) battery to the JST jack. This will let the Feather run on a rechargable battery.
The above shows the Micro USB jack (left), Lipoly JST jack (top left), as well as the 3.3V regulator and changeover diode (just to the right of the JST jack) and the Lipoly charging circuitry (to the right of the Reset button). There's also a CHG LED, which will light up while the battery is charging. This LED might also flicker if the battery is not connected.
#define VBATPIN A7 float measuredvbat = analogRead(VBATPIN); measuredvbat *= 2; // we divided by 2, so multiply back measuredvbat *= 3.3; // Multiply by 3.3V, our reference voltage measuredvbat /= 1024; // convert to voltage Serial.print("VBat: " ); Serial.println(measuredvbat); ENable pin If you'd like to turn off the 3.3V regulator, you can do that with the EN(able) pin. Simply tie this pin to Ground and it will disable the 3V regulator.
Arduino IDE Setup The first thing you will need to do is to download the latest release of the Arduino IDE. You will need to be using version 1.8 or higher for this guide Arduino IDE Download https://adafru.it/f1P After you have downloaded and installed the latest version of Arduino IDE, you will need to start the IDE and navigate to the Preferences menu. You can access it from the File menu in Windows or Linux, or the Arduino menu on OS X. A dialog will pop up just like the one shown below.
We will be adding a URL to the new Additional Boards Manager URLs option. The list of URLs is comma separated, and you will only have to add each URL once. New Adafruit boards and updates to existing boards will automatically be picked up by the Board Manager each time it is opened. The URLs point to index files that the Board Manager uses to build the list of available & installed boards.
Here's a short description of each of the Adafruit supplied packages that will be available in the Board Manager when you add the URL: Adafruit AVR Boards - Includes support for Flora, Gemma, Feather 32u4, Trinket, & Trinket Pro. Adafruit SAMD Boards - Includes support for Feather M0, Metro M0, Circuit Playground Express, Gemma M0 and Trinket M0 Arduino Leonardo & Micro MIDI-USB - This adds MIDI over USB support for the Flora, Feather 32u4, Micro and Leonardo using the arcore project.
Using with Arduino IDE Since the Feather/Metro/Gemma/Trinket M0 use an ATSAMD21 chip running at 48 MHz, you can pretty easily get it working with the Arduino IDE. Most libraries (including the popular ones like NeoPixels and display) will work with the M0, especially devices & sensors that use i2c or SPI. Now that you have added the appropriate URLs to the Arduino IDE preferences in the previous page, you can open the Boards Manager by navigating to the Tools->Board menu.
You can type Adafruit SAMD in the top search bar, then when you see the entry, click Install Even though in theory you don't need to - I recommend rebooting the IDE Quit and reopen the Arduino IDE to ensure that all of the boards are properly installed. You should now be able to select and upload to the new boards listed in the Tools->Board menu.
Download Latest Adafruit Drivers package https://adafru.it/A0N Download and run the installer Run the installer! Since we bundle the SiLabs and FTDI drivers as well, you'll need to click through the license Select which drivers you want to install, the defaults will set you up with just about every Adafruit board! Click Install to do the installin' © Adafruit Industries https://learn.adafruit.
Blink Now you can upload your first blink sketch! Plug in the Gemma M0, Trinket M0, Metro M0 or Feather M0 and wait for it to be recognized by the OS (just takes a few seconds). It will create a serial/COM port, you can now select it from the dropdown, it'll even be 'indicated' as Trinket/Gemma/Metro/Feather M0! Now load up the Blink example // the setup function runs once when you press reset or power the board void setup() { // initialize digital pin 13 as an output.
If you are having issues, make sure you selected the matching Board in the menu that matches the hardware you have in your hand. Sucessful Upload If you have a successful upload, you'll get a bunch of red text that tells you that the device was found and it was programmed, verified & reset Compilation Issues If you get an alert that looks like Cannot run program "{runtime.tools.arm-none-eabi-gcc.path}\bin\arm-non-eabi-g++" Make sure you have installed the Arduino SAMD boards package, you need both Arduino
Manually bootloading If you ever get in a 'weird' spot with the bootloader, or you have uploaded code that crashes and doesn't auto-reboot into the bootloader, click the RST button twice (like a double-click)to get back into the bootloader. The red LED will pulse, so you know that its in bootloader mode. Once it is in bootloader mode, you can select the newly created COM/Serial port and re-try uploading.
Adapting Sketches to M0 The ATSAMD21 is a very nice little chip but its fairly new as Arduino-compatible cores go. Most sketches & libraries will work but here's a few things we noticed! The below note are for all M0 boards, but not all may apply (e.g. Trinket and Gemma M0 do not have ARef so you can skip the Analog References note!) Analog References If you'd like to use the ARef pin for a non-3.
AnalogWrite / PWM on Feather/Metro M0 After looking through the SAMD21 datasheet, we've found that some of the options listed in the multiplexer table don't exist on the specific chip used in the Feather M0. For all SAMD21 chips, there are two peripherals that can generate PWM signals: The Timer/Counter (TC) and Timer/Counter for Control Applications (TCC). Each SAMD21 has multiple copies of each, called 'instances'. Each TC instance has one count register, one control register, and two output channels.
If only the SPI pins keep their protocol functions, you can also do PWM on the following pins: TX and SDA (Digital pins 1 and 20) analogWrite() PWM range On AVR, if you set a pin's PWM with analogWrite(pin, 255) it will turn the pin fully HIGH. On the ARM cortex, it will set it to be 255/256 so there will be very slim but still-existing pulses-to-0V.
access an odd-boundary byte (on a 1 or 3 byte location) will cause a Hard Fault and stop the MCU. Thankfully, there's an easy work around ... just use memcpy! uint8_t mybuffer[4]; float f; memcpy(f, mybuffer, 4) Floating Point Conversion Like the AVR Arduinos, the M0 library does not have full support for converting floating point numbers to ASCII strings. Functions like sprintf will not convert floating point.
Feather HELP! My Feather stopped working when I unplugged the USB! A lot of our example sketches have a while (!Serial); line in setup(), to keep the board waiting until the USB is opened. This makes it a lot easier to debug a program because you get to see all the USB data output.
I can't get the Feather USB device to show up - I get "USB Device Malfunctioning" errors! This seems to happen when people select the wrong board from the Arduino Boards menu. If you have a Feather 32u4 (look on the board to read what it is you have) Make sure you select Feather 32u4 for ATMega32u4 based boards! Do not use anything else, do not use the 32u4 breakout board line.
When the user COM port disappears, Arduino will not be able to automatically start the bootloader and upload new software.
Downloads Datasheets ATSAMD21 Datasheet (the main chip on the Feather M0) Fritzing object in the Adafruit Fritzing Library EagleCAD PCB files in GitHub Feather M0 Basic Proto Pinout Diagram https://adafru.it/z3f Firmware Feather M0 Bootloader - You'll need to program it in using an ST-Link, JLink or other SWD-capable programmer.
