README ====== This README discusses issues unique to NuttX configurations for the Atmel SAML21 Xplained Pro development board. This board features the ATSAML21J18A MCU. Contents ======== - STATUS/ISSUES - Modules - Development Environment - GNU Toolchain Options - IDEs - NuttX EABI "buildroot" Toolchain - LEDs and Buttons - Serial Consoles - Atmel Studio 6.1 - JTAG - SAML21 Xplained Pro-specific Configuration Options - Configurations STATUS/ISSUES ============= - Since this port is a leverage of the SAMD20 Xplained port, some of the STATUS/ISSUES in the SAMD20 Xplained README.txt may apply here as well. - 2015-5-26: The basic port is running at 48MHz (using 32.768 XTAL input and the digital frequency locked loop). The basic NuttShell (NSH) configuration is working well with the serial console provided by SERCOM4 as 115200 8N1. - 2015-6-14: Added a DMAC driver. There is no way to verify it at present and, hence, depends upon CONFIG_EXPERIMENTAL=y Modules ======= There are several I/O modules available that will work with the SAML21 Xplained Pro Starter Kit: 1) I/O1 - An MMC/SD card slot, PWM LED control, ADC light sensor, USART loopback, TWI AT30TSE758 Temperature sensor. 2) OLED1 - An OLED plus 3 additional switches and 3 additional LEDs 3) PROTO1 - A prototyping board with logic on board (other than power- related logic). 4) And others. See http://www.atmel.com/products/microcontrollers/avr/xplained.aspx Some of these are discussed further below. I/O1 ---- The primary function of this module is to provide SD card support, but the full list of modules features include: - microSD card connector (SPI interface) - PWM (LED control) - ADC (light sensor) - USART loopback - TWI AT30TSE758 Temperature sensor with EEPROM SPI is available on two of the SAML21 Xplained connectors, EXT1 and EXT2. They mate with the I/O1 connector as indicated in this table. I/O1 CONNECTOR ----------------- ---------------------- ---------------------- ------------------------------------ I/O1 EXT1 EXT2 Other use of either pin ----------------- ---------------------- ---------------------- ------------------------------------ 1 ID 1 1 Communication line to ID chip on extension board. ----------------- ---------------------- ---------------------- ------------------------------------ 2 GND 2 GND 2 GND ----------------- ---------------------- ---------------------- ------------------------------------ 3 LIGHTSENSOR 3 PB05 AIN[13] 3 PA10 AIN[18] ----------------- ---------------------- ---------------------- ------------------------------------ 4 LP_OUT 4 PA03 AIN[1] 4 PA11 AIN[19] ----------------- ---------------------- ---------------------- ------------------------------------ 5 GPIO1 5 PB06 GPIO 5 PA20 GPIO ----------------- ---------------------- ---------------------- ------------------------------------ 6 GPIO2 6 PB07 GPIO 6 PA21 GPIO ----------------- ---------------------- ---------------------- ------------------------------------ 7 LED 7 PA12 TCC2/WO[0] 7 PB12 TC4/WO[0] ----------------- ---------------------- ---------------------- ------------------------------------ 8 LP_IN 8 PA13 TCC2/WO[1] 8 PB13 TC4/WO[1] ----------------- ---------------------- ---------------------- ------------------------------------ 9 TEMP_ALERT 9 PB04 EXTINT[4] 9 PB14 EXTINT[14] ----------------- ---------------------- ---------------------- ------------------------------------ 10 microSD_DETECT 10 PA02 GPIO 10 PB15 GPIO ----------------- ---------------------- ---------------------- ------------------------------------ 11 TWI SDA 11 PA08 SERCOM2 PAD[0] 11 PA08 SERCOM2 PAD[0] EXT1, EXT2, EXT3 and EDBG I²C SDA I²C SDA ----------------- ---------------------- ---------------------- ------------------------------------ 12 TWI SCL 12 PA09 SERCOM2 PAD[1] 12 PA09 SERCOM2 PAD[1] EXT2, EXT3 and EDBG I²C SCL I²C SCL ----------------- ---------------------- ---------------------- ------------------------------------ 13 USART RX 13 PB09 SERCOM4 PAD[1] 13 PA19 SERCOM1 PAD[3] The SERCOM4 module is shared between USART RX USART RX EXT1, 2 and 3 USART's, but uses different pins ----------------- ---------------------- ---------------------- ------------------------------------ 14 USART TX 14 PB08 SERCOM4 PAD[0] 14 PA18 SERCOM1 PAD[2] The SERCOM4 module is shared between USART TX USART TX EXT1, 2 and 3 USART's, but uses different pins ----------------- ---------------------- ---------------------- ------------------------------------ 15 microSD_SS 15 PA05 SERCOM0 PAD[1] 15 PA17 GPIO SPI SS ----------------- ---------------------- ---------------------- ------------------------------------ 16 SPI_MOSI 16 PA06 SERCOM0 PAD[2] 16 PB22 SERCOM5 PAD[2] SPI MOSI SPI MOSI ----------------- ---------------------- ---------------------- ------------------------------------ 17 SPI_MISO 17 PA04 SERCOM0 PAD[0] 17 PB16 SERCOM5 PAD[0] SPI MISO SPI MISO ----------------- ---------------------- ---------------------- ------------------------------------ 18 SPI_SCK 18 PA07 SERCOM0 PAD[3] 18 PB23 SERCOM5 PAD[3] SPI SCK SPI SCK ----------------- ---------------------- ---------------------- ------------------------------------ 19 GND 19 GND GND ----------------- ---------------------- ---------------------- ------------------------------------ 20 VCC 20 VCC VCC ----------------- ---------------------- ---------------------- ------------------------------------ The mapping between the I/O1 pins and the SD connector are shown in the following table. SD Card Connection ------------------ I/O1 SD PIN Description ---- ---- --- ------------------------------------------------- D2 1 Data line 2 (not used) 15 D3 2 Data line 3. Active low chip select, pulled high 16 CMD 3 Command line, connected to SPI_MOSI. 20 VDD 4 18 CLK 5 Clock line, connected to SPI_SCK. 2/19 GND 6 17 D0 7 Data line 0, connected to SPI_MISO. D1 8 Data line 1 (not used) 10 SW_A 9 Card detect 2/19 SW_B 10 GND Card Detect ----------- When a microSD card is put into the connector SW_A and SW_B are short- circuited. SW_A is connected to the microSD_DETECT signal. To use this as a card indicator remember to enable internal pullup in the target device. GPIOs ----- So all that is required to connect the SD is configure the SPI --- ------------------ ---------------------- ------------------------------------- PIN EXT1 EXT2 Description --- ------------------ ---------------------- ------------------------------------- 15 PA05 SERCOM0 PAD[1] 15 PA17 GPIO Active low chip select OUTPUT, pulled SPI SS high on board. --- ------------------ ---------------------- ------------------------------------- 10 PA02 GPIO 10 PB15 GPIO Active low card detect INPUT, must use internal pull-up. --- ------------------ ---------------------- ------------------------------------- Configuration Options: ---------------------- CONFIG_SAML21_XPLAINED_IOMODULE=y : Informs the system that the I/O1 module is installed CONFIG_SAML21_XPLAINED_IOMODULE_EXT1=y : The module is installed in EXT1 CONFIG_SAML21_XPLAINED_IOMODULE_EXT2=y : The mdoule is installed in EXT2 See the set-up in the discussion of the nsh configuration below for other required configuration options. NOTE: As of this writing, only the SD card slot is supported in the I/O1 module. OLED1 ----- This module provides an OLED plus 3 additional switches and 3 additional LEDs. OLED1 CONNECTOR ----------------- ---------------------- ---------------------- ------------------------------------ OLED1 EXT1 EXT2 Other use of either pin ----------------- ---------------------- ---------------------- ------------------------------------ 1 ID 1 1 Communication line to ID chip on extension board. ----------------- ---------------------- ---------------------- ------------------------------------ 2 GND 2 GND 2 GND ----------------- ---------------------- ---------------------- ------------------------------------ 3 BUTTON2 3 PB05 AIN[13] 3 PA10 AIN[18] ----------------- ---------------------- ---------------------- ------------------------------------ 4 BUTTON3 4 PA03 AIN[1] 4 PA11 AIN[19] ----------------- ---------------------- ---------------------- ------------------------------------ 5 DATA_CMD_SEL 5 PB06 GPIO 5 PA20 GPIO ----------------- ---------------------- ---------------------- ------------------------------------ 6 LED3 6 PB07 GPIO 6 PA21 GPIO ----------------- ---------------------- ---------------------- ------------------------------------ 7 LED1 7 PA12 TCC2/WO[0] 7 PB12 TC4/WO[0] ----------------- ---------------------- ---------------------- ------------------------------------ 8 LED2 8 PA13 TCC2/WO[1] 8 PB13 TC4/WO[1] ----------------- ---------------------- ---------------------- ------------------------------------ 9 BUTTON1 9 PB04 EXTINT[4] 9 PB14 EXTINT[14] ----------------- ---------------------- ---------------------- ------------------------------------ 10 DISPLAY_RESET 10 PA02 GPIO 10 PB15 GPIO ----------------- ---------------------- ---------------------- ------------------------------------ 11 N/C 11 PA08 SERCOM2 PAD[0] 11 PA08 SERCOM2 PAD[0] EXT1, EXT2, EXT3 and EDBG I²C SDA I²C SDA ----------------- ---------------------- ---------------------- ------------------------------------ 12 N/C 12 PA09 SERCOM2 PAD[1] 12 PA09 SERCOM2 PAD[1] EXT2, EXT3 and EDBG I²C SCL I²C SCL ----------------- ---------------------- ---------------------- ------------------------------------ 13 N/C 13 PB09 SERCOM4 PAD[1] 13 PA19 SERCOM1 PAD[3] The SERCOM4 module is shared between USART RX USART RX EXT1, 2 and 3 USART's, but uses different pins ----------------- ---------------------- ---------------------- ------------------------------------ 14 N/C 14 PB08 SERCOM4 PAD[0] 14 PA18 SERCOM1 PAD[2] The SERCOM4 module is shared between USART TX USART TX EXT1, 2 and 3 USART's, but uses different pins ----------------- ---------------------- ---------------------- ------------------------------------ 15 DISPLAY_SS 15 PA05 SERCOM0 PAD[1] 15 PA17 GPIO SPI SS ----------------- ---------------------- ---------------------- ------------------------------------ 16 SPI_MOSI 16 PA06 SERCOM0 PAD[2] 16 PB22 SERCOM5 PAD[2] SPI MOSI SPI MOSI ----------------- ---------------------- ---------------------- ------------------------------------ 17 N/C 17 PA04 SERCOM0 PAD[0] 17 PB16 SERCOM5 PAD[0] SPI MISO SPI MISO ----------------- ---------------------- ---------------------- ------------------------------------ 18 SPI_SCK 18 PA07 SERCOM0 PAD[3] 18 PB23 SERCOM5 PAD[3] SPI SCK SPI SCK ----------------- ---------------------- ---------------------- ------------------------------------ 19 GND 19 GND GND ----------------- ---------------------- ---------------------- ------------------------------------ 20 VCC 20 VCC VCC ----------------- ---------------------- ---------------------- ------------------------------------ Configuration Options: ---------------------- CONFIG_SAML21_XPLAINED_OLED1MODULE=y : Informs the system that the I/O1 module is installed CONFIG_SAML21_XPLAINED_OLED1MODULE_EXT1=y : The module is installed in EXT1 CONFIG_SAML21_XPLAINED_OLED1MODULE_EXT2=y : The mdoule is installed in EXT2 See the set-up in the discussion of the nsh configuration below for other required configuration options. PROTO1 ------ A prototyping board with logic on board (other than power-related logic). There is no built-in support for the PROTO1 module. Development Environment ======================= Either Linux or Cygwin on Windows can be used for the development environment. The source has been built only using the GNU toolchain (see below). Other toolchains will likely cause problems. Testing was performed using the Cygwin environment. GNU Toolchain Options ===================== The NuttX make system can be configured to support the various different toolchain options. All testing has been conducted using the NuttX buildroot toolchain. To use alternative toolchain, you simply need to add change of the following configuration options to your .config (or defconfig) file: CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYW=y : CodeSourcery under Windows CONFIG_ARMV7M_TOOLCHAIN_CODESOURCERYL=y : CodeSourcery under Linux CONFIG_ARMV7M_TOOLCHAIN_ATOLLIC=y : Atollic toolchain for Windos CONFIG_ARMV7M_TOOLCHAIN_DEVKITARM=y : devkitARM under Windows CONFIG_ARMV7M_TOOLCHAIN_BUILDROOT=y : NuttX buildroot under Linux or Cygwin (default) CONFIG_ARMV7M_TOOLCHAIN_GNU_EABIL=y : Generic GCC ARM EABI toolchain for Linux CONFIG_ARMV7M_TOOLCHAIN_GNU_EABIW=y : Generic GCC ARM EABI toolchain for Windows You may also have to modify the PATH in the setenv.h file if your make cannot find the tools. NOTE about Windows native toolchains ------------------------------------ There are basically three kinds of GCC toolchains that can be used: 1. A Linux native toolchain in a Linux environment, 2. The buildroot Cygwin tool chain built in the Cygwin environment, 3. A Windows native toolchain. There are several limitations to using a Windows based toolchain (#3) in a Cygwin environment. The three biggest are: 1. The Windows toolchain cannot follow Cygwin paths. Path conversions are performed automatically in the Cygwin makefiles using the 'cygpath' utility but you might easily find some new path problems. If so, check out 'cygpath -w' 2. Windows toolchains cannot follow Cygwin symbolic links. Many symbolic links are used in Nuttx (e.g., include/arch). The make system works around these problems for the Windows tools by copying directories instead of linking them. But this can also cause some confusion for you: For example, you may edit a file in a "linked" directory and find that your changes had no effect. That is because you are building the copy of the file in the "fake" symbolic directory. If you use a Windows toolchain, you should get in the habit of making like this: make clean_context all An alias in your .bashrc file might make that less painful. IDEs ==== NuttX is built using command-line make. It can be used with an IDE, but some effort will be required to create the project. Makefile Build -------------- Under Eclipse, it is pretty easy to set up an "empty makefile project" and simply use the NuttX makefile to build the system. That is almost for free under Linux. Under Windows, you will need to set up the "Cygwin GCC" empty makefile project in order to work with Windows (Google for "Eclipse Cygwin" - there is a lot of help on the internet). Native Build ------------ Here are a few tips before you start that effort: 1) Select the toolchain that you will be using in your .config file 2) Start the NuttX build at least one time from the Cygwin command line before trying to create your project. This is necessary to create certain auto-generated files and directories that will be needed. 3) Set up include pathes: You will need include/, arch/arm/src/sam34, arch/arm/src/common, arch/arm/src/armv7-m, and sched/. 4) All assembly files need to have the definition option -D __ASSEMBLY__ on the command line. Startup files will probably cause you some headaches. The NuttX startup file is arch/arm/src/sam34/sam_vectors.S. You may need to build NuttX one time from the Cygwin command line in order to obtain the pre-built startup object needed by an IDE. NuttX EABI "buildroot" Toolchain ================================ A GNU GCC-based toolchain is assumed. The files */setenv.sh should be modified to point to the correct path to the Cortex-M0 GCC toolchain (if different from the default in your PATH variable). If you have no Cortex-M0 toolchain, one can be downloaded from the NuttX Bitbucket download site (https://bitbucket.org/nuttx/buildroot/downloads/). This GNU toolchain builds and executes in the Linux or Cygwin environment. 1. You must have already configured Nuttx in /nuttx. cd tools ./configure.sh saml21-xplained/ 2. Download the latest buildroot package into 3. unpack the buildroot tarball. The resulting directory may have versioning information on it like buildroot-x.y.z. If so, rename /buildroot-x.y.z to /buildroot. 4. cd /buildroot 5. cp configs/cortexm0-eabi-defconfig-4.6.3 .config 6. make oldconfig 7. make 8. Edit setenv.h, if necessary, so that the PATH variable includes the path to the newly built binaries. See the file configs/README.txt in the buildroot source tree. That has more details PLUS some special instructions that you will need to follow if you are building a Cortex-M0 toolchain for Cygwin under Windows. LEDs and Buttons ================ LED --- There is one yellow LED available on the SAML21 Xplained Pro board that can be turned on and off. The LED can be activated by driving the connected PB10 I/O line to GND. When CONFIG_ARCH_LEDS is defined in the NuttX configuration, NuttX will control the LED as follows: SYMBOL Meaning LED0 ------------------- ----------------------- ------ LED_STARTED NuttX has been started OFF LED_HEAPALLOCATE Heap has been allocated OFF LED_IRQSENABLED Interrupts enabled OFF LED_STACKCREATED Idle stack created ON LED_INIRQ In an interrupt N/C LED_SIGNAL In a signal handler N/C LED_ASSERTION An assertion failed N/C LED_PANIC The system has crashed FLASH Thus is LED is statically on, NuttX has successfully booted and is, apparently, running normally. If LED is flashing at approximately 2Hz, then a fatal error has been detected and the system has halted. Button ------ SAM L21 Xplained Pro contains one mechanical button on PA02 that can be controlled by software. When a button is pressed it will drive the I/O line to GND. Note: There is no pull-up resistor connected to the generic user button. Remember to enable the internal pull-up in the SAM L21 to use the button. QTouch Button ------------- To be provided Serial Consoles =============== SERCOM0 ------- SERCOM0 is dedicated for use with SPI at the EXT1 connector SERCOM1 ------- SERCOM1 is available as a USART on EXT2 and EXT3 PIN EXT1 EXT2 EXT3 GPIO Function ---- ---- ---- ---- ------------------ 13 --- PA19 PA19 SERCOM1 / USART RX 14 --- PA18 PA18 SERCOM1 / USART TX 19 GND GND GND N/A 20 VCC VCC VCC N/A SERCOM2 ------- SERCOM0 is dedicated for use with I2C at the EXT1, EXT2, and EXT3 connectors. SERCOM3 ------- SERCOM3 is not available on any EXT connector but is dedicated for use with Virtual COM (see below). SERCOM4 ------- SERCOM1 is available as a USART on EXT1 PIN EXT1 EXT2 EXT3 GPIO Function ---- ---- ---- ---- ------------------ 13 PB09 --- --- SERCOM4 / USART RX 14 PB08 --- --- SERCOM4 / USART TX 19 GND GND GND N/A 20 VCC VCC VCC N/A SERCOM5 ------- SERCOM5 is dedicated for use with SPI at the EXT2 and EXT3 connectors Configuration ------------- There are options available in the NuttX configuration to select which connector SERCOM4 is on: SAML21_XPLAINED_USART4_EXTn, where n=1, 2, or 3. If you have a TTL to RS-232 converter then this is the most convenient serial console to use (because you don't lose the console device each time you lose the USB connection). It is the default in all of these configurations. An option is to use the virtual COM port. Virtual COM Port ---------------- The SAML21 Xplained Pro contains an Embedded Debugger (EDBG) that can be used to program and debug the ATSAML21J18A using Serial Wire Debug (SWD). The Embedded debugger also include a Virtual COM port interface over SERCOM3. Virtual COM port connections: PA22 SERCOM3 / USART TXD PA23 SERCOM3 / USART RXD Atmel Studio 6.1 ================ NOTE: These instructions are old. The SAML21 requires Atmel Studio 6.2. They may still prove useful to you, however. Loading Code into FLASH: ----------------------- Tools menus: Tools -> Device Programming. Debugging the NuttX Object File ------------------------------- 1) Rename object file from nutt to nuttx.elf. That is an extension that will be recognized by the file menu. 2) File menu: File -> Open -> Open object file for debugging - Select nuttx.elf object file - Select AT91SAML21J18 - Select files for symbols as desired - Select debugger 3) Debug menu: Debug -> Start debugging and break - This will reload the nuttx.elf file into FLASH JTAG ==== I did all of the debug of the SAML21 Xplained using a Segger J-Link connected to the micro JTAG connector on board the SAML21 Xplained. I used an Olimex ARM-JTAG 20-10 Adapter to connect the J-Link to the SAML21 Xplained. SAML21 Xplained Pro-specific Configuration Options ================================================== CONFIG_ARCH - Identifies the arch/ subdirectory. This should be set to: CONFIG_ARCH=arm CONFIG_ARCH_family - For use in C code: CONFIG_ARCH_ARM=y CONFIG_ARCH_architecture - For use in C code: CONFIG_ARCH_CORTEXM0=y CONFIG_ARCH_CHIP - Identifies the arch/*/chip subdirectory CONFIG_ARCH_CHIP="samdl" CONFIG_ARCH_CHIP_name - For use in C code to identify the exact chip: CONFIG_ARCH_CHIP_SAML CONFIG_ARCH_CHIP_SAML21 CONFIG_ARCH_CHIP_ATSAML21J18 CONFIG_ARCH_BOARD - Identifies the configs subdirectory and hence, the board that supports the particular chip or SoC. CONFIG_ARCH_BOARD="saml21-xplained" (for the SAML21 Xplained Pro development board) CONFIG_ARCH_BOARD_name - For use in C code CONFIG_ARCH_BOARD_SAML21_XPLAINED=y CONFIG_ARCH_LOOPSPERMSEC - Must be calibrated for correct operation of delay loops CONFIG_ENDIAN_BIG - define if big endian (default is little endian) CONFIG_RAM_SIZE - Describes the installed DRAM (SRAM in this case): CONFIG_RAM_SIZE=0x00010000 (64KB) CONFIG_RAM_START - The start address of installed DRAM CONFIG_RAM_START=0x20000000 CONFIG_ARCH_LEDS - Use LEDs to show state. Unique to boards that have LEDs CONFIG_ARCH_INTERRUPTSTACK - This architecture supports an interrupt stack. If defined, this symbol is the size of the interrupt stack in bytes. If not defined, the user task stacks will be used during interrupt handling. CONFIG_ARCH_STACKDUMP - Do stack dumps after assertions CONFIG_ARCH_LEDS - Use LEDs to show state. Unique to board architecture. CONFIG_ARCH_CALIBRATION - Enables some build in instrumentation that cause a 100 second delay during boot-up. This 100 second delay serves no purpose other than it allows you to calibratre CONFIG_ARCH_LOOPSPERMSEC. You simply use a stop watch to measure the 100 second delay then adjust CONFIG_ARCH_LOOPSPERMSEC until the delay actually is 100 seconds. Individual subsystems can be enabled: CONFIG_SAMDL_AC - Analog Comparator CONFIG_SAMDL_ADC - Analog-to-Digital Converter CONFIG_SAMDL_DAC - Digital-to-Analog Converter CONFIG_SAMDL_DMAC - Analog Comparator CONFIG_SAMDL_EVSYS - Event System CONFIG_SAMDL_NVMCTRL - Non-Volatile Memory Controller CONFIG_SAMDL_PTC - Peripheral Touch Controller CONFIG_SAMDL_RTC - Real Time Counter CONFIG_SAMDL_SERCOM0 - Serial Communication Interface 0 CONFIG_SAMDL_SERCOM1 - Serial Communication Interface 1 CONFIG_SAMDL_SERCOM2 - Serial Communication Interface 2 CONFIG_SAMDL_SERCOM3 - Serial Communication Interface 3 CONFIG_SAMDL_SERCOM4 - Serial Communication Interface 4 CONFIG_SAMDL_SERCOM5 - Serial Communication Interface 5 CONFIG_SAMDL_TCC0 - Timer/Counter 0 for Control CONFIG_SAMDL_TCC1 - Timer/Counter 1 for Control CONFIG_SAMDL_TCC2 - Timer/Counter 2 for Control CONFIG_SAMDL_TC3 - Timer/Counter 3 CONFIG_SAMDL_TC4 - Timer/Counter 4 CONFIG_SAMDL_TC5 - Timer/Counter 5 CONFIG_SAMDL_TC6 - Timer/Counter 6 CONFIG_SAMDL_TC7 - Timer/Counter 6 CONFIG_SAMDL_USB - USB device or host CONFIG_SAMDL_WDT - Watchdog Timer Some subsystems can be configured to operate in different ways. The drivers need to know how to configure the subsystem. CONFIG_SAMDL_SERCOM0_ISI2C, CONFIG_SAMDL_SERCOM0_ISSPI, or CONFIG_SAMDL_SERCOM0_ISUSART CONFIG_SAMDL_SERCOM1_ISI2C, CONFIG_SAMDL_SERCOM1_ISSPI, or CONFIG_SAMDL_SERCOM1_ISUSART CONFIG_SAMDL_SERCOM2_ISI2C, CONFIG_SAMDL_SERCOM2_ISSPI, or CONFIG_SAMDL_SERCOM2_ISUSART CONFIG_SAMDL_SERCOM3_ISI2C, CONFIG_SAMDL_SERCOM3_ISSPI, or CONFIG_SAMDL_SERCOM3_ISUSART CONFIG_SAMDL_SERCOM4_ISI2C, CONFIG_SAMDL_SERCOM4_ISSPI, or CONFIG_SAMDL_SERCOM4_ISUSART CONFIG_SAMDL_SERCOM5_ISI2C, CONFIG_SAMDL_SERCOM5_ISSPI, or CONFIG_SAMDL_SERCOM5_ISUSART SAML21 specific device driver settings CONFIG_USARTn_SERIAL_CONSOLE - selects the USARTn (n=0,1,2,..5) for the console and ttys0 (default is the USART4). CONFIG_USARTn_RXBUFSIZE - Characters are buffered as received. This specific the size of the receive buffer CONFIG_USARTn_TXBUFSIZE - Characters are buffered before being sent. This specific the size of the transmit buffer CONFIG_USARTn_BAUD - The configure BAUD of the USART. Must be CONFIG_USARTn_BITS - The number of bits. Must be either 7 or 8. CONFIG_USARTn_PARTIY - 0=no parity, 1=odd parity, 2=even parity CONFIG_USARTn_2STOP - Two stop bits Configurations ============== Each SAML21 Xplained Pro configuration is maintained in a sub-directory and can be selected as follow: cd tools ./configure.sh saml21-xplained/ cd - . ./setenv.sh Before sourcing the setenv.sh file above, you should examine it and perform edits as necessary so that BUILDROOT_BIN is the correct path to the directory than holds your toolchain binaries. And then build NuttX by simply typing the following. At the conclusion of the make, the nuttx binary will reside in an ELF file called, simply, nuttx. make The that is provided above as an argument to the tools/configure.sh must be is one of the following. NOTE: These configurations use the mconf-based configuration tool. To change any of these configurations using that tool, you should: a. Build and install the kconfig-mconf tool. See nuttx/README.txt see additional README.txt files in the NuttX tools repository. b. Execute 'make menuconfig' in nuttx/ in order to start the reconfiguration process. NOTES: 1. These configurations use the mconf-based configuration tool. To change any of these configurations using that tool, you should: a. Build and install the kconfig-mconf tool. See nuttx/README.txt see additional README.txt files in the NuttX tools repository. b. Execute 'make menuconfig' in nuttx/ in order to start the reconfiguration process. 2. Unless stated otherwise, all configurations generate console output of on SERCOM4 which is available on EXT1 (see the section "Serial Consoles" above). The SERCOM1 on EXT2 or EXT3 or the virtual COM port on SERCOME could be used, instead, by reconfiguring to use SERCOM1 or SERCOM3 instead of SERCOM4: System Type -> SAMD/L Peripheral Support CONFIG_SAMDL_SERCOM1=y : Enable one or both CONFIG_SAMDL_SERCOM3=y CONFIG_SAMDL_SERCOM4=n Device Drivers -> Serial Driver Support -> Serial Console CONFIG_USART1_SERIAL_CONSOLE=y : Select only one for the console CONFIG_USART3_SERIAL_CONSOLE=y : Select only one for the console CONFIG_USART4_SERIAL_CONSOLE=n Device Drivers -> Serial Driver Support -> SERCOMn Configuration where n=1 or 3: CONFIG_USARTn_2STOP=0 CONFIG_USARTn_BAUD=115200 CONFIG_USARTn_BITS=8 CONFIG_USARTn_PARITY=0 CONFIG_USARTn_RXBUFSIZE=256 CONFIG_USARTn_TXBUFSIZE=256 3. Unless otherwise stated, the configurations are setup for Cygwin under Windows: Build Setup: CONFIG_HOST_WINDOWS=y : Windows Host CONFIG_WINDOWS_CYGWIN=y : Cygwin environment on windoes 4. These configurations use the CodeSourcery toolchain. But that is easily reconfigured: System Type -> Toolchain: CONFIG_ARMV6M_TOOLCHAIN_CODESOURCERYW=y Any re-configuration should be done before making NuttX or else the subsequent 'make' will fail. If you have already attempted building NuttX then you will have to 1) 'make distclean' to remove the old configuration, 2) 'cd tools; ./configure.sh sam3u-ek/ksnh' to start with a fresh configuration, and 3) perform the configuration changes above. Also, make sure that your PATH variable has the new path to your Atmel tools. Try 'which arm-none-eabi-gcc' to make sure that you are selecting the right tool. setenv.sh is available for you to use to set or PATH variable. The path in the that file may not, however, be correct for your installation. See also the "NOTE about Windows native toolchains" in the section called "GNU Toolchain Options" above. Configuration sub-directories ----------------------------- nsh: This configuration directory will built the NuttShell. See NOTES above and below: NOTES: 1. This configuration is set up to build on Windows using the Cygwin environment using the CodeSourcery toolchain. This can be easily changed as described above under "Configurations." 2. By default, this configuration provides a serial console on SERCOM4 at 115200 8N1 via EXT1: PIN EXT1 GPIO Function ---- ---- ------------------ 13 PB09 SERCOM4 / USART RX 14 PB08 SERCOM4 / USART TX 19 GND N/A 20 VCC N/A If you would prefer to use the EDBG serial COM port or would prefer to use SERCOM4 on EXT1 or EXT2, you will need to reconfigure the SERCOM as described under "Configurations". See also the section entitled "Serial Consoles" above. 3. NOTE: If you get a compilation error like: libxx_new.cxx:74:40: error: 'operator new' takes type 'size_t' ('unsigned int') as first parameter [-fper Sometimes NuttX and your toolchain will disagree on the underlying type of size_t; sometimes it is an 'unsigned int' and sometimes it is an 'unsigned long int'. If this error occurs, then you may need to toggle the value of CONFIG_CXX_NEWLONG. 4. WARNING: This info comes from the SAMD20 Xplained README. I have not tried the I/O1 module on the SAML21! If the I/O1 module is connected to the SAML21 Xplained Pro, then support for the SD card slot can be enabled by making the following changes to the configuration. These changes assume that the I/O1 modules is connected in EXT1. Most of the modifications necessary to work with the I/O1 in a different connector are obvious.. except for the selection of SERCOM SPI support: EXT1: SPI is provided through SERCOM0 EXT2: SPI is provided through SERCOM1 EXT3: SPI is provided through SERCOM5 File Systems: CONFIG_FS_FAT=y : Enable the FAT file system CONFIG_FAT_LCNAMES=y : Enable upper/lower case 8.3 file names (Optional, see below) CONFIG_FAT_LFN=y : Enable long file named (Optional, see below) CONFIG_FAT_MAXFNAME=32 : Maximum supported file name length There are issues related to patents that Microsoft holds on FAT long file name technologies. See the top level COPYING file for further details. System Type -> Peripherals: CONFIG_SAMDL_SERCOM0=y : Use SERCOM0 if the I/O is in EXT1 CONFIG_SAMDL_SERCOM0_ISSPI=y : Configure SERCOM0 as an SPI master Device Drivers CONFIG_SPI=y : Enable SPI support CONFIG_SPI_EXCHANGE=y : The exchange() method is supported CONFIG_MMCSD=y : Enable MMC/SD support CONFIG_MMCSD_NSLOTS=1 : Only one MMC/SD card slot CONFIG_MMCSD_MULTIBLOCK_DISABLE=n : Should not need to disable multi-block transfers CONFIG_MMCSD_MMCSUPPORT=n : May interfere with some SD cards CONFIG_MMCSD_HAVECARDDETECT=y : I/O1 module as a card detect GPIO CONFIG_MMCSD_SPI=y : Use the SPI interface to the MMC/SD card CONFIG_MMCSD_SPICLOCK=20000000 : This is a guess for the optimal MMC/SD frequency CONFIG_MMCSD_SPIMODE=0 : Mode 0 is required Board Selection -> Common Board Options CONFIG_NSH_MMCSDSLOTNO=0 : Only one MMC/SD slot, slot 0 CONFIG_NSH_MMCSDSPIPORTNO=0 : Use port=0 -> SERCOM0 if the I/O1 is in EXT1 Board Selection -> SAML21 Xplained Pro Modules CONFIG_SAML21_XPLAINED_IOMODULE=y : I/O1 module is connected CONFIG_SAML21_XPLAINED_IOMODULE_EXT2=y : I/O1 modules is in EXT2 Application Configuration -> NSH Library CONFIG_NSH_ARCHINIT=y : Board has architecture-specific initialization NOTE: If you enable the I/O1 this configuration with SERCOM4 as the console and with the I/O1 module in EXT1, you *must* remove USART jumper. Otherwise, you have lookback on SERCOM4 and NSH will *not* behave very well (since its outgoing prompts also appear as incoming commands). STATUS: As of 2013-6-18, this configuration appears completely functional. Testing, however, has been very light. Example: NuttShell (NSH) NuttX-6.34 nsh> mount -t vfat /dev/mmcsd0 /mnt/stuff nsh> ls /mnt/stuff /mnt/stuff: nsh> echo "This is a test" >/mnt/stuff/atest.txt nsh> ls /mnt/stuff /mnt/stuff: atest.txt nsh> cat /mnt/stuff/atest.txt This is a test nsh> 5. WARNING: This info comes from the SAMD20 Xplained README. I have not tried the OLED1 module on the SAML21! 5. If the OLED1 module is connected to the SAML21 Xplained Pro, then support for the OLED display can be enabled by making the following changes to the configuration. These changes assume that the I/O1 modules is connected in EXT1. Most of the modifications necessary to work with the I/O1 in a different connector are obvious.. except for the selection of SERCOM SPI support: EXT1: SPI is provided through SERCOM0 EXT2: SPI is provided through SERCOM1 EXT3: SPI is provided through SERCOM5 System Type -> Peripherals: CONFIG_SAMDL_SERCOM1=y : Use SERCOM1 if the I/O is in EXT2 CONFIG_SAMDL_SERCOM1_ISSPI=y : Configure SERCOM1 as an SPI master Device Drivers -> SPI CONFIG_SPI=y : Enable SPI support CONFIG_SPI_EXCHANGE=y : The exchange() method is supported CONFIG_SPI_CMDDATA=y : CMD/DATA support is required Device Drivers -> LCDs CONFIG_LCD=y : Enable LCD support CONFIG_LCD_MAXCONTRAST=255 : Maximum contrast value CONFIG_LCD_LANDSCAPE=y : Landscape orientation (see below*) CONFIG_LCD_UG2832HSWEG04=y : Enable support for the OLED CONFIG_LCD_SSD1306_SPIMODE=0 : SPI Mode 0 CONFIG_LCD_SSD1306_SPIMODE=3500000 : Pick an SPI frequency Board Selection -> SAML21 Xplained Pro Modules CONFIG_SAML21_XPLAINED_OLED1MODULE=y : OLED1 module is connected CONFIG_SAML21_XPLAINED_OLED1MODULE_EXT2=y : OLED1 modules is in EXT2 The NX graphics subsystem also needs to be configured: CONFIG_NX=y : Enable graphics support CONFIG_NX_LCDDRIVER=y : Using an LCD driver CONFIG_NX_NPLANES=1 : With a single color plane CONFIG_NX_WRITEONLY=n : You can read from the LCD (see below*) CONFIG_NX_DISABLE_2BPP=y : Disable all resolutions except 1BPP CONFIG_NX_DISABLE_4BPP=y CONFIG_NX_DISABLE_8BPP=y CONFIG_NX_DISABLE_16BPP=y CONFIG_NX_DISABLE_24BPP=y CONFIG_NX_DISABLE_32BPP=y CONFIG_NX_PACKEDMSFIRST=y : LSB packed first (shouldn't matter) CONFIG_NXTK_BORDERWIDTH=2 : Use a small border CONFIG_NXTK_DEFAULT_BORDERCOLORS=y : Default border colors CONFIG_NXFONTS_CHARBITS=7 : 7-bit fonts CONFIG_NXFONT_SANS17X23B=y : Pick a font (any that will fit) * The hardware is write only, but the driver maintains a frame buffer to support read and read-write-modiry operations on the LCD. Reading from the frame buffer is, however, untested. Then, in order to use the OLED, you will need to build some kind of graphics application or use one of the NuttX graphics examples. Here, for example, is the setup for the graphic "Hello, World!" example: CONFIG_EXAMPLES_NXHELLO=y : Enables the example CONFIG_EXAMPLES_NXHELLO_DEFAULT_COLORS=y : Use default colors (see below *) CONFIG_EXAMPLES_NXHELLO_DEFAULT_FONT=y : Use the default font CONFIG_EXAMPLES_NXHELLO_BPP=1 : One bit per pixel CONFIG_EXAMPLES_NXHELLO_EXTERNINIT=y : Special initialization is required. * The OLED is monochrome so the only "colors" are black and white. The default "colors" will give you while text on a black background. You can override the faults it you want black text on a while background.