README ====== This README discusses issues unique to NuttX configurations for the STMicro STM32L-Discovery development board. The STM32L-Discovery board is based on the STM32L152RBT6 MCU (128KB FLASH and 16KB of SRAM). The STM32L-Discovery and 32L152CDISCOVERY kits are functionally equivalent. The difference is the internal Flash memory size (STM32L152RBT6 with 128 Kbytes or STM32L152RCT6 with 256 Kbytes). Both boards feature: - An ST-LINK/V2 embedded debug tool interface, - LCD (24 segments, 4 commons), - LEDs, - Pushbuttons, - A linear touch sensor, and - Four touchkeys. Contents ======== - Status - GPIO Pin Usage - LEDs - Serial Console - Debugging - STM32L-Discovery-specific Configuration Options - Configurations Status ====== The basic port is complete. A NuttShell (NSH) configuration exists for the STM32L-Discovery board. A driver has been developed for the segment LCD on board the STM32L-Discovery. In the NSH configuration description below, there is information about how the basic NSH extension can be extended to use apps/examples/slcd to exercise the segment LCD. * The following subsystem have header files, drivers and have been exercised: PWR, RCC, GPIO, SYSCFG, LCD, USART. * The following subsystems have header files and ported drivers, but are untested: DMA * The following subsystems have counterparts with other STM32 parts, but have not been ported or verified: ADC, DAC, TIM2-15, TIM9-11, RTC, IWDG, WWDG, I2C, SPI, DBG. These may be close to functional depending upon how close the IP is on the STM32L15X. This might include also USB, FSMC, and SDIO. * The following subsystems are unique to the STM32L and have not been developed: COMP, TSIO, RI, OPAMP * The STM32L15X does support USB, however, USB is not available on the STM32L-Discovery board. * These subsystems are available on other STM32L15x/16x parts, but not on the part used in the STM32L-Discovery board: CRC, AES, FSMC, SDIO GPIO Pin Usage ============== ----- --------------------- -------------------------------- ---------------- GPIO ALTERNATE FUNCTION BOARD FUNCTION P1/P2 ----- --------------------- -------------------------------- ---------------- PA0 WKUP1/USART2_CTS/ Push button (PA0), WAKE UP (Iuu) P1, pin 15 ADC_IN0/TIM2_CH1_ETR /COMP1_INP PA1 USART2_RTS/ADC_IN1/ LCD SEG0 P1, pin 16 TIM2_CH2/LCD_SEG0/ COMP1_INP PA2 USART2_TX/ADC_IN2/ LCD SEG1 P1, pin 17 TIM2_CH3/TIM9_CH1/ LCD_SEG1/COMP1_INP PA3 USART2_RX/ADC_IN3/ LCD SEG2 P1, pin 18 TIM2_CH4/TIM9_CH2/ LCD_SEG2/COMP1_INP PA4 SPI1_NSS/USART2_CK/ Measurement (Iuu) P1, pin 19 ADC_IN4/DAC_OUT1/ COMP1_INP PA5 SPI1_SCK/ADC_IN5/ --- P1, pin 20 DAC_OUT2/ TIM2_CH1_ETR/COMP1_ INP PA6 SPI1_MISO/ADC_IN6/ Linear Touch Sensor (PA6) --- TIM3_CH1/TIM1_BKIN/ LCD_SEG3/TIM10_CH1/ COMP1_INP PA7 SPI1_MOSI/ADC_IN7/ Linear Touch Sensor (PA7) --- TIM3_CH2/TIM1_CH1N /LCD_SEG4/TIM11_CH1/ PA8 USART1_CK/MCO/ LCD glass COM0 P2, pin 23 LCD_COM0 PA9 USART1_TX/LCD_COM1 LCD glass COM1 P2, pin 22 PA10 USART1_RX/LCD_COM2 LCD glass COM2 P2, pin 21 PA11 USART1_CTS/USBDM/ --- P2, pin 20 SPI1_MISO PA12 USART1_RTS/USBDP/ --- P2, pin 19 SPI1_MOSI JTDI TIM2_CH1_ETR/PA15/ LCD_SEG12 P2, pin 16 SPI1_NSS/LCD_SEG17 ----- --------------------- -------------------------------- ---------------- PB0 ADC_IN8/TIM3_CH3/ Linear Touch Sensor (PB0) --- LCD_SEG5/COMP1_INP/ VREF_OUT PB1 ADC_IN9/TIM3_CH4/ Linear Touch Sensor (PB1) --- LCD_SEG6/COMP1_INP/ VREF_OUT PB2/ --- --- P1, pin 21 BOOT1 JTDO TIM2_CH2/PB3/TRACES LCD_SEG3, SWO P2, pin 11 WO/SPI1_SCK/COMP2_I NM/LCD_SEG7 JNTRST TIM3_CH1/PB4/SPI1_MIS SEG4 P2, pin 10 O/COMP2_INP/LCD_SEG8 PB5 I2C1_SMBAl/TIM3_CH2/ LCD SEG5 P2, pin 9 SPI1_MOSI/COMP2_INP/ LCD_SEG9 PB6 I2C1_SCL/TIM4_CH1/ LED Blue P2, pin 8 USART1_TX/LCD_SEG8 PB7 I2C1_SDA/TIM4_CH2/ LED Green P2, pin 7 USART1_RX/PVD_IN PB8 TIM4_CH3/I2C1_SCL/ LCD SEG13 P2, pin 4 LCD_SEG16/TIM10_CH1 PB9 TIM4_CH4/I2C1_SDA/ LCD glass COM3 P2, pin 3 LCD_COM3/TIM11_CH1 PB10 I2C2_SCL/USART3_TX/ LCD SEG6 P1, pin 22 TIM2_CH3/LCD_SEG10 PB11 I2C2_SDA/USART3_RX/ LCD SEG7 P1, pin 23 TIM2_CH4/LCD_SEG11 PB12 SPI2_NSS/I2C2_SMBA/ LCD SEG8 P1, pin 24 USART3_CK/LCD_SEG12 2/ADC_IN18/COMP1_INP / TIM10_CH1 PB13 SPI2_SCK/USART3_CTS/ LCD SEG9 P1, pin 25 LCD_SEG13/ADC_IN19/ COMP1_INP/TIM9_CH1 PB14 SPI2_MISO/USART3_RT LCD SEG10 P1, pin 26 S/LCD_SEG14/ADC_IN20 / COMP1_INP/TIM9_CH2 PB15 SPI2_MOSI/TIM1_CH3N/ LCD SEG11 P1, pin 27 LCD_SEG15/ADC_IN21/ COMP1_INP/TIM11_CH1/ RTC_50_60Hz ----- --------------------- -------------------------------- ---------------- PC0 ADC_IN10/LCD_SEG18/ LCD SEG14 P1, pin 11 COMP1_INP PC1 ADC_IN11/LCD_SEG19/ LCD SEG15 P1, pin 12 COMP1_INP PC2 ADC_IN12/LCD_SEG20/ LCD SEG16 P1, pin 13 COMP1_INP PC3 ADC_IN13/LCD_SEG21/ LCD SEG17 P1, pin 14 COMP1_INP PC4 ADC_IN14/LCD_SEG22/ Linear Touch Sensor (PC4) --- COMP1_INP PC5 ADC_IN15/LCD_SEG23/ Linear Touch Sensor (PC5) --- COMP1_INP PC6 TIM3_CH1/LCD_SEG24 LCD SEG18 P2, pin 27 PC7 TIM3_CH2/LCD_SEG25 LCD SEG19 P2, pin 26 PC8 TIM3_CH3/LCD_SEG26 LCD SEG20 P2, pin 25 PC9 TIM3_CH4/LCD_SEG27 LCD SEG21 P2, pin 24 PC10 USART3_TX/LCD_SEG28 LCD SEG22 P2, pin 15 /LCD_SEG40/LCD_COM4 PC11 USART3_RX/LCD_SEG2 LCD SEG23 P2, pin 14 9/LCD_SEG41/ LCD_COM5 PC12 USART3_CK/LCD_SEG3 --- P2, pin 13 0/LCD_SEG42/ LCD_COM6 PC13 RTC_AF1/WKUP2 2 CNT_ IDD CNT_EN P1, pin 4 EN 4 PC14 OSC32_IN 3 OSC32_IN OSC32_IN P1, pin 5 PC15 OSC32_OUT 4 OSC32_OUT OSC32_OUT P1, pin 6 ----- --------------------- -------------------------------- ---------------- PD2 TIM3_ETR/LCD_SEG31/ --- P2, pin 12 LCD_SEG43/LCD_COM7 ----- --------------------- -------------------------------- ---------------- LEDs ==== The STM32L-Discovery board has four LEDs. Two of these are controlled by logic on the board and are not available for software control: LD1 COM: LD2 default status is red. LD2 turns to green to indicate that communications are in progress between the PC and the ST-LINK/V2. LD2 PWR: Red LED indicates that the board is powered. And two LEDs can be controlled by software: User LD3: Green LED is a user LED connected to the I/O PB7 of the STM32L152 MCU. User LD4: Blue LED is a user LED connected to the I/O PB6 of the STM32L152 MCU. These LEDs are not used by the board port unless CONFIG_ARCH_LEDS is defined. In that case, the usage by the board port is defined in include/board.h and src/stm32_autoleds.c. The LEDs are used to encode OS-related events as follows: SYMBOL Meaning LED state LED3 LED4 ------------------- ----------------------- -------- -------- LED_STARTED NuttX has been started OFF OFF LED_HEAPALLOCATE Heap has been allocated OFF OFF LED_IRQSENABLED Interrupts enabled OFF OFF LED_STACKCREATED Idle stack created ON OFF LED_INIRQ In an interrupt No change LED_SIGNAL In a signal handler No change LED_ASSERTION An assertion failed No change LED_PANIC The system has crashed OFF Blinking LED_IDLE STM32 is is sleep mode Not used Serial Console ============== The STM32L-Discovery has no on-board RS-232 driver. Further, there are no USART pins that do not conflict with the on board resources, in particular, the LCD: Most USART pins are available if the LCD is enabled; USART2 may be used if either the LCD or the on-board LEDs are disabled. PA9 USART1_TX LCD glass COM1 P2, pin 22 PA10 USART1_RX LCD glass COM2 P2, pin 21 PB6 USART1_TX LED Blue P2, pin 8 PB7 USART1_RX LED Green P2, pin 7 PA2 USART2_TX LCD SEG1 P1, pin 17 PA3 USART2_RX LCD SEG2 P1, pin 18 PB10 USART3_TX LCD SEG6 P1, pin 22 PB11 USART3_RX LCD SEG7 P1, pin 23 PC10 USART3_TX LCD SEG22 P2, pin 15 PC11 USART3_RX LCD SEG23 P2, pin 14 NOTES: - GND and (external) 5V are available on both P1 and P2. Note: These signals may be at lower voltage levels and, hence, may not properly drive an external RS-232 transceiver. - The crystal X3 is not installed on the STM32L3-Discovery. As a result, the HSE clock is not available and the less accurate HSI must be used. This may limit the accuracy of the computed baud, especially at higher BAUD. The HSI is supposedly calibrated in the factory to within 1% at room temperatures so perhaps this not a issue. - According to the STM32L-Discovery User Manual, the LCD should be removed from its socket if you use any of the LCD pins for any other purpose. I have had no problems using the USART1 with PA9 and PA10 with a 3.3-5V RS-232 transceiver module at 57600 baud. I have not tried higher baud rates. - There is no support for a USB serial connector on the STM32L-Discovery board. The STM32L152 does support USB, but the USB pins are "free I/O" on the board and no USB connector is provided. So the use of a USB console is not option. If you need console output, you will need to disable either LCD (and use any USART) or the LEDs (and use USART1) Debugging ========= STM32 ST-LINK Utility --------------------- For simply writing to FLASH, I use the STM32 ST-LINK Utility. At least version 2.4.0 is required (older versions do not recognize the STM32 F3 device). This utility is available from free from the STMicro website. Debugging --------- If you are going to use a debugger, you should make sure that the following settings are selection in your configuration file: CONFIG_DEBUG_SYMBOLS=y : Enable debug symbols in the build CONFIG_ARMV7M_USEBASEPRI=y : Use the BASEPRI register to disable interrupts OpenOCD ------- I am told that OpenOCD will work with the ST-Link, but I have never tried it. https://github.com/texane/stlink -------------------------------- This is an open source server for the ST-Link that I have never used. STM32L-Discovery-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_CORTEXM4=y CONFIG_ARCH_CHIP - Identifies the arch/*/chip subdirectory CONFIG_ARCH_CHIP=stm32 CONFIG_ARCH_CHIP_name - For use in C code to identify the exact chip: CONFIG_ARCH_CHIP_STM32L152RB=y CONFIG_ARCH_BOARD_STM32_CUSTOM_CLOCKCONFIG - Enables special STM32 clock configuration features. CONFIG_ARCH_BOARD_STM32_CUSTOM_CLOCKCONFIG=n CONFIG_ARCH_BOARD - Identifies the boards/ subdirectory and hence, the board that supports the particular chip or SoC. CONFIG_ARCH_BOARD=stm32fldiscovery (for the STM32L-Discovery development board) CONFIG_ARCH_BOARD_name - For use in C code CONFIG_ARCH_BOARD_STM32FLDISCOVERY=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=16384 (16Kb) CONFIG_RAM_START - The start address of installed DRAM CONFIG_RAM_START=0x20000000 CONFIG_STM32_CCMEXCLUDE - Exclude CCM SRAM from the HEAP CONFIG_ARCH_FPU - The STM32L-Discovery does not support a floating point unit (FPU) CONFIG_ARCH_FPU=n 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. Individual subsystems can be enabled: AHB ---- (GPIOs are always enabled) CONFIG_STM32_FLITF CONFIG_STM32_DMA1 CONFIG_STM32_DMA2 APB2 ---- CONFIG_STM32_SYSCFG CONFIG_STM32_TIM9 CONFIG_STM32_TIM10 CONFIG_STM32_TIM11 CONFIG_STM32_ADC1 CONFIG_STM32_SPI1 CONFIG_STM32_USART1 APB1 ---- CONFIG_STM32_TIM2 CONFIG_STM32_TIM3 CONFIG_STM32_TIM4 CONFIG_STM32_TIM5 CONFIG_STM32_TIM6 CONFIG_STM32_TIM7 CONFIG_STM32_LCD CONFIG_STM32_WWDG CONFIG_STM32_IWDG CONFIG_STM32_SPI2 CONFIG_STM32_SPI3 CONFIG_STM32_USART2 CONFIG_STM32_USART3 CONFIG_STM32_I2C1 CONFIG_STM32_I2C2 CONFIG_STM32_USB CONFIG_STM32_PWR -- Required for RTC CONFIG_STM32_DAC1 CONFIG_STM32_COMP Timer devices may be used for different purposes. One special purpose is to generate modulated outputs for such things as motor control. If CONFIG_STM32_TIMn is defined (as above) then the following may also be defined to indicate that the timer is intended to be used for pulsed output modulation, ADC conversion, or DAC conversion. Note that ADC/DAC require two definition: Not only do you have to assign the timer (n) for used by the ADC or DAC, but then you also have to configure which ADC or DAC (m) it is assigned to. CONFIG_STM32_TIMn_PWM Reserve timer n for use by PWM, n=1,..,14 CONFIG_STM32_TIMn_ADC Reserve timer n for use by ADC, n=1,..,14 CONFIG_STM32_TIMn_ADCm Reserve timer n to trigger ADCm, n=1,..,14, m=1,..,3 CONFIG_STM32_TIMn_DAC Reserve timer n for use by DAC, n=1,..,14 CONFIG_STM32_TIMn_DACm Reserve timer n to trigger DACm, n=1,..,14, m=1,..,2 For each timer that is enabled for PWM usage, we need the following additional configuration settings: CONFIG_STM32_TIMx_CHANNEL - Specifies the timer output channel {1,..,4} NOTE: The STM32 timers are each capable of generating different signals on each of the four channels with different duty cycles. That capability is not supported by this driver: Only one output channel per timer. JTAG Enable settings (by default only SW-DP is enabled): CONFIG_STM32_JTAG_FULL_ENABLE - Enables full SWJ (JTAG-DP + SW-DP) CONFIG_STM32_JTAG_NOJNTRST_ENABLE - Enables full SWJ (JTAG-DP + SW-DP) but without JNTRST. CONFIG_STM32_JTAG_SW_ENABLE - Set JTAG-DP disabled and SW-DP enabled STM32L-Discovery specific device driver settings CONFIG_U[S]ARTn_SERIAL_CONSOLE - selects the USARTn (n=1,2,3) or UART m (m=4,5) for the console and ttys0 (default is the USART1). CONFIG_U[S]ARTn_RXBUFSIZE - Characters are buffered as received. This specific the size of the receive buffer CONFIG_U[S]ARTn_TXBUFSIZE - Characters are buffered before being sent. This specific the size of the transmit buffer CONFIG_U[S]ARTn_BAUD - The configure BAUD of the UART. Must be CONFIG_U[S]ARTn_BITS - The number of bits. Must be either 7 or 8. CONFIG_U[S]ARTn_PARTIY - 0=no parity, 1=odd parity, 2=even parity CONFIG_U[S]ARTn_2STOP - Two stop bits STM32L-Discovery CAN Configuration CONFIG_CAN - Enables CAN support (one or both of CONFIG_STM32_CAN1 or CONFIG_STM32_CAN2 must also be defined) CONFIG_CAN_EXTID - Enables support for the 29-bit extended ID. Default Standard 11-bit IDs. CONFIG_CAN_FIFOSIZE - The size of the circular buffer of CAN messages. Default: 8 CONFIG_CAN_NPENDINGRTR - The size of the list of pending RTR requests. Default: 4 CONFIG_CAN_LOOPBACK - A CAN driver may or may not support a loopback mode for testing. The STM32 CAN driver does support loopback mode. CONFIG_STM32_CAN1_BAUD - CAN1 BAUD rate. Required if CONFIG_STM32_CAN1 is defined. CONFIG_STM32_CAN2_BAUD - CAN1 BAUD rate. Required if CONFIG_STM32_CAN2 is defined. CONFIG_STM32_CAN_TSEG1 - The number of CAN time quanta in segment 1. Default: 6 CONFIG_STM32_CAN_TSEG2 - the number of CAN time quanta in segment 2. Default: 7 CONFIG_STM32_CAN_REGDEBUG - If CONFIG_DEBUG_FEATURES is set, this will generate an dump of all CAN registers. STM32L-Discovery SPI Configuration CONFIG_STM32_SPI_INTERRUPTS - Select to enable interrupt driven SPI support. Non-interrupt-driven, poll-waiting is recommended if the interrupt rate would be to high in the interrupt driven case. CONFIG_STM32_SPI_DMA - Use DMA to improve SPI transfer performance. Cannot be used with CONFIG_STM32_SPI_INTERRUPT. Configurations ============== Each STM32L-Discovery configuration is maintained in a sub-directory and can be selected as follow: tools/configure.sh STM32L-Discovery: Where is one of the following sub-directories. 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. Configuration sub-directories ----------------------------- nsh: --- Configures the NuttShell (nsh) located at apps/examples/nsh. NOTES: 1. The serial console is on UART1 and NuttX LED support is enabled. Therefore, you will need an external RS232 driver or TTL serial-to- USB converter. The UART1 TX and RX pins should be available on PA9 and PA10, respectively. The serial console is configured for 57600 8N1 by default. 2. Support for NSH built-in applications is *not* enabled. 3. By default, this configuration uses the ARM EABI toolchain for Windows and builds under Cygwin (or probably MSYS). That can easily be reconfigured, of course. Build Setup: CONFIG_HOST_WINDOWS=y : Builds under Windows CONFIG_WINDOWS_CYGWIN=y : Using Cygwin System Type: CONFIG_ARMV7M_TOOLCHAIN_GNU_EABIW=y : GNU EABI toolchain for Windows 4. To enable SLCD support: Board Selection: CONFIG_ARCH_LEDS=n : Disable board LED support Library Routines: CONFIG_LIB_SLCDCODEC=y : Enable the SLCD CODEC System Type -> STM32 Peripheral Support: CONFIG_STM32_LCD=y : Enable the Segment LCD When the LCD is enabled and the LEDs are disabled, the USART1 serial console will automatically move to PB6 and PB7 (you will get a compilation error if you forget to disable the LEDs). SIGNAL FUNCTION LED CONNECTION ------ ---------- ---------- ----------- PB6 USART1_TX LED Blue P2, pin 8 PB7 USART1_RX LED Green P2, pin 7 To enable apps/examples/slcd to test the SLCD: Binary Formats: CONFIG_BINFMT_DISABLE=n : Don't disable binary support CONFIG_BUILTIN=y : Enable support for built-in binaries Application Configuration -> NSH Library: CONFIG_NSH_BUILTIN_APPS=y : Enable builtin apps in NSH CONFIG_NSH_ARCHINIT=y : Needed to initialize the SLCD Application Configuration -> Examples: CONFIG_EXAMPLES_SLCD=y : Enable apps/examples/slcd To enable LCD debug output: Device Drivers: CONFIG_LCD=y : (Needed to enable LCD debug) Build Setup -> Debug Options: CONFIG_DEBUG_FEATURES=y : Enable debug features CONFIG_DEBUG_INFO=y : Enable LCD debug NOTE: At this point in time, testing of the SLCD is very limited because there is not much in apps/examples/slcd. Certainly there are more bugs to be found. There are also many segment-encoded glyphs in stm32_lcd.c But there is a basically functional driver with a working test setup that can be extended if you want a fully functional SLCD driver.