Low-power Application Kit (Oryx) - User’s Guide Copyright 2012 © Embedded Artists AB Low-Power Application Kit (Oryx) - powered by LPCXpresso Get Up-and-Running Quickly and Start Developing Your Application On Day 1! EA-USG-1207 Rev A
Low-power Application Kit (Oryx) - User’s Guide Page 2 Embedded Artists AB Davidshallsgatan 16 211 45 Malmö Sweden info@EmbeddedArtists.com http://www.EmbeddedArtists.com Copyright 2012 © Embedded Artists AB. All rights reserved.
Low-power Application Kit (Oryx) - User’s Guide Page 3 Table of Contents 1 Document Revision History 5 2 Introduction 6 2.1 Features 6 2.2 ESD Precaution 7 2.3 General Handling Care 7 2.4 Code Read Protection 7 2.5 Other Products from Embedded Artists 7 2.5.1 Design and Production Services 7 2.5.2 OEM / Education / QuickStart Boards and Kits 8 3 The Low-power Application Board Design 9 3.1 Block Diagram 9 3.2 Board Overview 10 3.3 Usage of CPU Pins 10 3.
Low-power Application Kit (Oryx) - User’s Guide Page 4 5.3.5 Temperature Sensor 28 5.3.6 Accelerometer Sensor 29 5.3.7 Capacitive Sensor 29 5.3.8 LPC11U37 Brown Out Detector 29 5.4 5.4.1 5.5 How to Measure Current Consumption How to Achieve and Measure 2.5uA Current Consumption The Sample Applications 6 Troubleshooting 29 30 32 6.1.1 Cannot download/debug 32 6.1.2 Battery drain quickly 32 6.1.
Low-power Application Kit (Oryx) - User’s Guide Page 5 1 Document Revision History Document Revision Date Description A 2011-11-07 First release version.
Low-power Application Kit (Oryx) - User’s Guide Page 6 2 Introduction Thank you for buying the Low-power Application Kit (Oryx) – powered by LPCXpresso from Embedded Artists. The board demonstrates low power design techniques both in hardware and software. The board has been developed by Embedded Artists in close cooperation with Arrow and NXP. The board contains an LPC11U37 MCU from NXP and has the same embedded-JTAG solution (called LPCLINK) as LPCXpresso target boards.
Low-power Application Kit (Oryx) - User’s Guide 2x5 pos, 50 mil/1.27 mm pitch, standard SWD/JTAG connector Compact size: 140 x 85 mm 2.
Low-power Application Kit (Oryx) - User’s Guide 2.5.2 Page 8 OEM / Education / QuickStart Boards and Kits Visit Embedded Artists’ home page, www.EmbeddedArtists.com, for information about other OEM / Education / QuickStart boards / kits or contact your local distributor.
Low-power Application Kit (Oryx) - User’s Guide Page 9 3 The Low-power Application Board Design This chapter describes the hardware design of the board. 3.1 Block Diagram The block diagram in Figure 1 below gives a quick overview of a design. It illustrates the major components in the design. The center of the design is the LPC11U37 MCU from NXP. A number of low-power peripherals are connected to the LPC11U37 via the I2C and SPI interfaces.
Low-power Application Kit (Oryx) - User’s Guide Page 10 There is also an LPCXpresso compatible embedded SWD/JTAG interface (called LPC-LINK). This simplifies program download and debugging. The interface can be completely disconnected in order not to affect the power consumption when running an application on the LPC11U37. 3.2 Board Overview Figure 2 below illustrates the board structure. The upper part is the original LPCXpresso LPC11U37 design.
Low-power Application Kit (Oryx) - User’s Guide Page 11 PIO0_7 LED Pin 11 PIO0_8 LCD disp Pin 6 PIO0_9 SPI channel#0 MOSI Pin 5 PIO0_10 SWD interface SWCLK Pin 24 PIO0_11 RTC irq Pin 15 PIO0_12 Capacitive sensor irq Pin 16 PIO0_13 Accelerometer irq#1 Pin 17 PIO0_14 Accelerometer irq#2 Pin 18 PIO0_15 SWD interface SWDIO Pin 19 PIO0_16 Wakeup push-button Pin 20 PIO0_17 Can be used to digitally indicate power consumption Pin 21 Pin 3 PIO0_18 Can be used to digitally indicat
Low-power Application Kit (Oryx) - User’s Guide Page 12 PIO1_31 Not used, free for expansion Pin 52 USB-DM USB interface Pin 36 USB-DP USB interface Pin 37 3.4 Schematic Walkthrough 3.4.1 Page 2 The center of the board is the LPC11U37 from NXP. It is a MCU based on the ARM Cortex-M0 core. LPC11U37 has many power modes to save power consumption. See datasheet for details. It is possible to measure the current consumption of the LPC11U37 on both VDD pins separately (IO and VDDCORE).
Low-power Application Kit (Oryx) - User’s Guide Page 13 There is a current consumption cost for keeping the chip active and detecting (single/double) taps. Exact current consumption depends on setup of detection, for example sample rate. See datasheet for details. If the chip is placed in standby mode, the current consumption is only 100 nA (= 0.3 uW). The I2C address to the ADXL345 chip is 0x1D (0.0.1.1.1.0.1.rw). Details about the ADXL345 chip operation can be found in the datasheet.
Low-power Application Kit (Oryx) - User’s Guide Page 14 the possibility to wake-up the LPC11U37 from a low-power mode. If the capacitive sensors are completely disabled (i.e., the PCF8885 is in sleep mode) the current consumption is only 100 nA (= 0.3 uW). Since the sleep mode current consumption is so low, the chip is always powered (i.e., there is no power switch). PIO1_15 can be used to control sleep mode of the PCF8885. 3.4.
Low-power Application Kit (Oryx) - User’s Guide Page 15 R30 can be replaced with R29 via SJ1 (connect pad 2-3 instead of pad 1-2, which is default) if the default value of 30 ohm is not suitable. Be careful to select a proper value for R29 so that the 50 mA maximum shunt current of LTC4071 is not exceeded. See LTC4071 datasheet for details. A low dropout linear voltage regulator is use to convert the battery voltage to 3.0V. TPS78330 from Texas Instruments is used for this. It is a 3.
Low-power Application Kit (Oryx) - User’s Guide Page 16 4 Getting Started This chapter contains information about how to get acquainted with the Low-power Application Kit (Oryx). Please read this chapter first before you starts using the board - it will be well spent time! The design contains many different components that interact with software.
Low-power Application Kit (Oryx) - User’s Guide 4.3 Page 17 Compiling the Demo Application This section describes how to compile the demo application in particular and any sample application in general. The principles are identical between applications how to compile them. First make sure that the latest version of the LPCXpresso IDE is installed. Secondly, import the package of sample application projects into the Eclipse workspace.
Low-power Application Kit (Oryx) - User’s Guide Page 18 1) Browse and select archived project file 2) Select all subprojects in list 3) Import project Figure 4 – LPCXpresso IDE Import Archived Project Window All sample projects are now imported. Click (to select) the project named ‘DemoApp’. Browse and edit the project files. Build/clean/debug the project from the Quickstart menu (Start here), see picture below.
Low-power Application Kit (Oryx) - User’s Guide Page 19 1) Click (to select) main project 2) Browse and edit project files 3) Build/clean/debug project Figure 5 – LPCXpresso IDE Build/Debug Project 4.4 Program Download This section describes how to download an application to the board, i.e., to the LPC11U37. 1. Connect a USB cable between J9 on the board and the PC. See Figure 2 to locate J9 (upper left corner). J9 is the LPC-LINK debugging interface (the debug interface of LPCXpresso). 2.
Low-power Application Kit (Oryx) - User’s Guide Page 20 5. Click on the "Program Flash" icon from the tool bar, see picture below. The icon can be at different places depending on window size. Program Flash Icon Figure 6 – LPCXpresso IDE Program Flash Icon The next step is to select which processor to download to. Select LPC11U37/501 from the list that is presented. Then press OK button.
Low-power Application Kit (Oryx) - User’s Guide Page 21 Figure 7 – LPCXpresso IDE Program Flash Window Browse to the projects top directory and then “Debug”. In this subfolder there is either a file ending with *.axf or *.bin. Select one of these files. Press the “Open” button. 1) Find workspace and all sample apps. 2) Find project top directory 3) Find “Debug” subdirectory Figure 8 – Browse to File to Download Copyright 2012 © Embedded Artists AB 4) Select either *.axf or *.
Low-power Application Kit (Oryx) - User’s Guide Page 22 Figure 9 – LPCXpresso IDE Program Flashing in Progress In case flashing fails, an error message like below will be displays. This is an indication that the debugger could not connect to the LPC11U37. The most common reason is that the LPC11U37 was in a low-power mode where debug connection is not possible. Make sure the LPC11U37 is in ISP/bootload mode and try again. Also make sure the small 10-pos flat cable is connected between J1 and J10.
Low-power Application Kit (Oryx) - User’s Guide Page 23 There is an alternative way of initiating the program download process. From the workspace, right click on the *.axf or *.bin file (found under the “Debug” subdirectory). Then select “Binary Utility” and “Program Flash”. 1) Right click on *.axf or *.bin file 2) Select “Binary Utility” 3) Select “Program Flash” Figure 11 – LPCXpresso IDE Binary Utility Press the reset push-button.
Low-power Application Kit (Oryx) - User’s Guide 4.5 Default Jumper Positions The default jumper positions on the board are shown below.
Low-power Application Kit (Oryx) - User’s Guide Page 25 5 Software Techniques for Low-power Design This chapter will discuss low-power design techniques. Part of the discussion is general for all lowpower designs and part is specific for the board design. Low-power design has two main principles: 1. Design the hardware to be able to control the current consumption by enabling/disabling different parts of the hardware.
Low-power Application Kit (Oryx) - User’s Guide Page 26 Deep power down – this mode has the lowest power consumption. All parts of the chip are powered down expect five 32-bit registers. The program structure is different (than with the other modes) if this mode is used because the processor wakes up again like after a reset. The content of the 5 registers is the only information left from before entering this mode.
Low-power Application Kit (Oryx) - User’s Guide Page 27 5.2 Typical Software Architecture for Low-Power When creating an application that uses low-power modes there is a typical design pattern to be used.
Low-power Application Kit (Oryx) - User’s Guide Page 28 The SPI clock is set to 750kHz. One byte transfer takes about 13.4uS. During SPI transfers the LPC11U37 does not have much to do, other than waiting for the SPI transfer to complete. The processor core frequency is haled during this time, which results in about half the normal current consumption. Note that the clock frequency to the SPI peripheral block is not affected. Toggling the VCOM bit takes 70uS all in all including all interrupt handling.
Low-power Application Kit (Oryx) - User’s Guide 5.3.6 Page 29 Accelerometer Sensor The accelerometer can be placed in a sleep mode where the current consumption is 0.1uA maximum. Read the datasheet for the accelerometer to get information about active mode and associated current consumption. There are different sample rates that can be programmed and resulting in different current consumption. 5.3.
Low-power Application Kit (Oryx) - User’s Guide Page 30 resistor. A 2.5uA current will result in a 7.5mV voltage drop over a 5K ohm resistor. This is much easier to measure. Use the sample application called LCD_ADC_temp_wdt-wakeup. Make sure that the symbol DISABLE_WDT_WAKEUP is defined (see line 50 in main.c of this sample application). Rebuild the project and download it. By defining the symbol DISABLE_WDT_WAKEUP, the application will stay n power down mode forever, once entered.
Low-power Application Kit (Oryx) - User’s Guide Page 31 also programs some BMP pictures on the serial flash. This application can be used to verify that a specific board is correct (if a hardware error is suspected). RTC_irq-wakeup – this application demonstrates the RTC and how the 1Hz tick can be used. Semihosting_ADC_temperature_sleep – this application demonstrates semihosting, which is a technique where an application can use printf() to display information on the LPCXpresso IDE.
Low-power Application Kit (Oryx) - User’s Guide Page 32 6 Troubleshooting This chapter contains information about how to troubleshoot boards that does not seem to operate properly. It is strongly advised to read through the list of tests and actions that can be done before contacting Arrow. The different tests can help determine if there is a problem with the board, or not. For return policy, please read Embedded Artists’ General Terms & Conditions document.
Low-power Application Kit (Oryx) - User’s Guide Page 33 If the production test signals that all tests pass, then there is likely no hardware issue with the board. Whatever problem that is experienced is probably because of a software issue.
Low-power Application Kit (Oryx) - User’s Guide Page 34 7 Further Information The LPC11U37 microcontroller is a complex circuit and there exist a number of other documents with a lot more information. The following documents are recommended as a complement to this document. [1] NXP LPC11U37 Datasheet www.nxp.com/documents/data_sheet/LPC11U3X.pdf [2] NXP LPC11U37 User’s Manual http://www.nxp.com/download/pip/LPC11U37FBD48/user_manual [3] NXP LPC11U37 Errata www.nxp.com/documents/errata_sheet/ES_LPC11U3X.
