================= stm32f401rc-rs485 ================= This page discusses issues unique to NuttX configurations for the NuttX STM32F4-RS485 development board. .. figure:: stm32f401rc_rs485.jpg :align: center Board information ================= This board was release on NuttX International Workshop 2023 and developed based on STM32F401RCT6 microcontroller. STM32F401RCT6 microcontroller features: - Arm 32-bit Cortex®-M4 CPU with FPU - 256 Kbytes of Flash memory - 64 Kbytes of SRAM - Serial wire debug (SWD) & JTAG interfaces - Up to 81 I/O ports with interrupt capability - Up to 11 communication interfaces - Up to 3 I2C interfaces - Up to 3 USARTs - Up to 4 SPIs - SDIO interface - USB 2.0 full-speed device/host/OTG controller with on-chip PHY The board features: - Digital I2C Temperature Sensor (TMP75) - 2K bits (256x8) I2C EEPROM - On-board RS485 Transceiver - Two Analog Input Stages with Amplifier Buffer - Two Analog Output Stages with Amplifier Buffer - MicroSD Connector supporting 1 or 4-bit bus - Four User LEDs - Four User Buttons - USB for DFU (Device Firmware Update) and USB device functionality, as well as powering the board - Onboard voltage regulator from 5V to 3.3V - SWD Pins for use as STLink (Pin header) and TC2030-IDC 6-Pin Tag-Connect Plug-of-Nails™ Connector - Crystal for HS 8MHz - Crystal for RTC 32.768KHz Board documentation: https://github.com/lucaszampar/NuttX_STM32F4_RS485_DevBoard As F4 series have a USB DFuSe-capable BootROM [AN2606], the board can be flashed via `dfu-util` over USB, or via `stm32flash` over UART without any debuggers. LEDs ==== The STM32F4-RS485 has 4 software controllable LEDs. ===== ===== LED PINS ===== ===== LED_1 PC0 LED_2 PC1 LED_4 PC2 LED_5 PC3 ===== ===== User Buttons ============ The STM32F4-RS485 has 4 user switches. ======= ===== ====== SWITCH PINS LABEL ======= ===== ====== SWIO_1 PB13 SW3 SWIO_2 PB14 SW4 SWIO_3 PB15 SW5 SWIO_4 PC6 SW6[1] ======= ===== ====== [1] The switch SWIO_4 (SW6) is disabled due a conflict with PIN PC6 when using USART6. UARTs ===== The STM32F4-RS485 has 1 USART available for user. USART6 ------ ========== ======= UART/USART PINS ========== ======= TX PC6 [1] RX PC7 CK PA8 ========== ======= [1] Warning you make need to reverse RX/TX on some RS-232 converters SDCard support ============== The STM32F4-RS485 has 1 SDCard slot connected as below: ========== ===== SDIO PINS ========== ===== SDIO_D0 PC8 SDIO_D1 PC9 SDIO_D2 PC10 SDIO_D3 PC11 SDIO_DK PC12 ========== ===== EEPROM ====== The STM32F4-RS485 development board has serial EEPROM HX24LC02B, with 2k bits (256x8) and internally organized with 32 pages of 8 bytes each. It is connected through I2C as below: ====== ===== I2C PINS ====== ===== SDA PB7 SCL PB8 ====== ===== Users can enable EERPOM support on STM32F4-RS485 by following below configuration: - Configure basic nsh:: ./tools/configure.sh -l stm32f401rc-rs485:nsh - Enable the following configs:: CONFIG_DEV_ZERO=y CONFIG_EEPROM=y CONFIG_FS_PROCFS=y CONFIG_I2C=y CONFIG_I2C_EE_24XX=y CONFIG_STM32_I2C1=y - Build and flash the STM32F4-RS485. - Use dd command to write and read data from EEPROM as below:: nsh> dd if=/dev/zero of=/dev/eeprom nsh: dd: write failed: 1 nsh> dd if=/dev/console of=/dev/eeprom bs=1 count=4 (type "Hello") nsh> dd if=/dev/eeprom of=/dev/console bs=4 count=1 Hellonsh> Temperature Sensor ================== The STM32F4-RS485 development board has a temperature sensor TMP75 (compatible with LM75) connected through I2C as below: ====== ===== I2C PINS ====== ===== SDA PB7 SCL PB8 ====== ===== RS485 Transceiver ================= The STM32F4-RS485 development board has a half-duplex RS-485 transceiver, the BL3085B it is connected through USART2 as below: ========== ===== USART2 PINS ========== ===== USART2_RX RO USART2_RTS DE, /RE USART2_RX DI ========== ===== A/D Converter ============= The STM32F4-RS485 development board has two Analog to Digital converters with Amplifier Buffer (1COS724SR) and connected as below: ======= ===== PWM PINS ======= ===== PWM_1 PB6 PWM_2 PA6 ======= ===== D/C Converter ============= The STM32F4-RS485 development board has two Digital to Analog converters with Amplifier Buffer (1COS724SR) and connected as below: ======= ===== ADC PINS ======= ===== ADC_1 PA0 ADC_2 PA4 ======= ===== Configurations ============== Each stm32f401rc-rs485 configuration is maintained in a sub-directory and can be selected as follow:: tools/configure.sh stm32f401rc-rs485: Where is one of the following: Configuration Directories ------------------------- nsh --- Configures the NuttShell (nsh) located at apps/examples/nsh. This configuration enables a serial console on USART6. usbnsh ------ Configures the NuttShell (nsh) located at apps/examples/nsh. This configuration enables a serial console over USB. After flasing and reboot your board you should see in your dmesg logs:: [ 2638.948089] usb 1-1.4: new full-speed USB device number 16 using xhci_hcd [ 2639.054432] usb 1-1.4: New USB device found, idVendor=0525, idProduct=a4a7, bcdDevice= 1.01 [ 2639.054437] usb 1-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 2639.054438] usb 1-1.4: Product: CDC/ACM Serial [ 2639.054440] usb 1-1.4: Manufacturer: NuttX [ 2639.054441] usb 1-1.4: SerialNumber: 0 [ 2639.074861] cdc_acm 1-1.4:1.0: ttyACM0: USB ACM device [ 2639.074886] usbcore: registered new interface driver cdc_acm [ 2639.074887] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters You may need to press **ENTER** 3 times before the NSH show up. sdcard ------ Configures the NuttShell (nsh) and enables SD card support. The stm32f401rc-rs485 has an onboard microSD slot that should be automatically registered as the block device /dev/mmcsd0 when an SD card is present. The SD card can then be mounted by the NSH commands:: nsh> mount -t procfs /proc nsh> mount -t vfat /dev/mmcsd0 /mnt modbus_slave ------------ Configures the NuttShell (nsh) and enables modbus in slave mode. This configuration enables a serial console on USART6. The RS-485 is connected to USART2. Follow below precedure to use modbus test aplication, you will need a USB to RS-485 converter to connect the board to a PC via RS-485. NuttShell configuration: Run modbus application at NSH:: nsh> modbus -help USAGE: modbus [-d|e|s|q|h] Where: -d : Disable protocol stack -e : Enable the protocol stack -s : Show current status -q : Quit application -h : Show this information nsh> modbus -e PC Configuration: Download and install mbpoll aplication:: sudo apt install mbpoll Check which TTY USB port is being used by you USB to RS-485 converter:: sudo dmesg [99846.668209] usb 1-1.3: Product: USB Serial [99846.676313] ch341 1-1.3:1.0: ch341-uart converter detected [99846.677454] usb 1-1.3: ch341-uart converter now attached to ttyUSB1 Run the mbpoll as below:: mbpoll -a 10 -b 38400 -t 3 -r 1000 -c 4 /dev/ttyUSB1 -R At PC terminal you will see the mbpoll application receiving the random values generated by STM32F401RC-RS485 and transmitted over RS-485:: mbpoll 1.0-0 - FieldTalk(tm) Modbus(R) Master Simulator Copyright © 2015-2019 Pascal JEAN, https://github.com/epsilonrt/mbpoll This program comes with ABSOLUTELY NO WARRANTY. This is free software, and you are welcome to redistribute it under certain conditions; type 'mbpoll -w' for details. Protocol configuration: Modbus RTU Slave configuration...: address = [10] start reference = 1000, count = 4 Communication.........: /dev/ttyUSB1, 38400-8E1 t/o 1.00 s, poll rate 1000 ms Data type.............: 16-bit register, input register table -- Polling slave 10... Ctrl-C to stop) [1000]: 58080 (-7456) [1001]: 0 [1002]: 0 [1003]: 0 -- Polling slave 10... Ctrl-C to stop) [1000]: 6100 [1001]: 0 [1002]: 0 [1003]: 0 -- Polling slave 10... Ctrl-C to stop) [1000]: 51010 (-14526) [1001]: 0 [1002]: 0 [1003]: 0 -- Polling slave 10... Ctrl-C to stop) [1000]: 12528 [1001]: 0 [1002]: 0 [1003]: 0 modbus_master ------------- Configures the NuttShell (nsh) and enables modbus in master mode. This configuration enables a serial console on USART6. The RS-485 is connected to USART2. Follow below precedure to use modbusmaster test aplication, you will need a USB to RS-485 converter to connect the board to a PC via RS-485. PC Configuration: Download and install diagslave aplication from https://www.modbusdriver.com/diagslave.html. Check which TTY USB port is being used by you USB to RS-485 converter:: sudo dmesg [99846.668209] usb 1-1.3: Product: USB Serial [99846.676313] ch341 1-1.3:1.0: ch341-uart converter detected [99846.677454] usb 1-1.3: ch341-uart converter now attached to ttyUSB1 Run the diagslave as below:: sudo diagslave -a 10 -b 38400 /dev/ttyUSB1 At PC terminal you will see the diagslave application listening to address 10, notice that this address is configurable via MODBUSMASTER_SLAVEADDR:: diagslave 3.4 - FieldTalk(tm) Modbus(R) Diagnostic Slave Simulator Copyright (c) 2002-2021 proconX Pty Ltd Visit https://www.modbusdriver.com for Modbus libraries and tools. Protocol configuration: Modbus RTU, frame tolerance = 0ms Slave configuration: address = 10, master activity t/o = 3.00s Serial port configuration: /dev/ttyUSB1, 38400, 8, 1, even Server started up successfully. Listening to network (Ctrl-C to stop) Slave 10: readHoldingRegisters from 2, 1 references ....... NuttShell configuration: Run modbusmaster application at NSH:: NuttShell (NSH) NuttX-12.4.0 nsh> modbusmaster Initializing modbus master... Creating poll thread. Sending 100 requests to slave 10 mbmaster_main: Exiting poll thread. Modbus master statistics: Requests count: 100 Responses count: 100 Errors count: 0 Deinitializing modbus master... The application modbusmaster will send 100 requests, you can check on diagslave:: Server started up successfully. Listening to network (Ctrl-C to stop) Slave 10: readHoldingRegisters from 2, 1 references Slave 10: readHoldingRegisters from 2, 1 references Slave 10: readHoldingRegisters from 2, 1 references Slave 10: readHoldingRegisters from 2, 1 references Slave 10: readHoldingRegisters from 2, 1 references Slave 10: readHoldingRegisters from 2, 1 references Slave 10: readHoldingRegisters from 2, 1 references lm75 ---- Configures the NuttShell (nsh) over USB Serial (check usbserial configuration) and enables temperature sensor LM75. NSH commands:: nsh> lm75 -help Usage: temp [OPTIONS] [-n count] selects the samples to collect. Default: 1 Current: 100 [-h] shows this message and exits nsh> lm75 -n 3 30.13 degrees Celsius 30.13 degrees Celsius 30.13 degrees Celsius adc --- Configures the NuttShell (nsh) over USB Serial (check usbserial configuration) and enables ADC 1 on channels 0 and 4. NSH commands:: nsh> adc -h Usage: adc [OPTIONS] Arguments are "sticky". For example, once the ADC device is specified, that device will be re-used until it is changed. "sticky" OPTIONS include: [-p devpath] selects the ADC device. Default: /dev/adc0 Current: /dev/adc0 [-n count] selects the samples to collect. Default: 1 Current: 0 [-h] shows this message and exits nsh> adc -n 2 adc_main: g_adcstate.count: 2 adc_main: Hardware initialized. Opening the ADC device: /dev/adc0 Sample: 1: channel: 0 value: 2684 Sample: 1: channel: 4 value: 2682 Currently there is a bug that causes the application to always read the same value for channel 0 and 4. If you want to read the value from channel 2, you will need to enable the config "ADC1 Scan Mode". dac --- Configures the NuttShell (nsh) over USB Serial (check usbserial configuration) and enables PWM 3 on channel 1. Use pwm command on NSH to change dutty cycle, frequency and duration, use dac_out_2 to measure the output voltage. NSH commands:: nsh> pwm -h Usage: pwm [OPTIONS] Arguments are "sticky". For example, once the PWM frequency is specified, that frequency will be re-used until it is changed. "sticky" OPTIONS include: [-p devpath] selects the PWM device. Default: /dev/pwm0 Current: NONE [-f frequency] selects the pulse frequency. Default: 100 Hz Current: 100 Hz [-d duty] selects the pulse duty as a percentage. Default: 50 % Current: 50 % [-t duration] is the duration of the pulse train in seconds. Default: 5 Current: 5 [-h] shows this message and exits nsh> pwm -d 50 -t 3 pwm_main: starting output with frequency: 50 duty: 00007fff pwm_main: stopping output qencoder -------- Configures the NuttShell (nsh) over USB Serial (check usbserial configuration) and enables Timer 3 on channels 1 and 2 to handle Quadrature Encoder. NSH commands:: nsh> qe -help Usage: qe [OPTIONS] OPTIONS include: [-p devpath] QE device path [-n samples] Number of samples [-t msec] Delay between samples (msec) [-r] Reset the position to zero [-h] Shows this message and exits nsh> qe -p /dev/qe0 -n 5 -t 100 -r nsh: qe: too many arguments qe_main: Hardware initialized. Opening the encoder device: /dev/qe0 qe_main: Resetting the count... qe_main: Number of samples: 5 qe_main: 1. 0 qe_main: 2. 0 qe_main: 3. 4 qe_main: 4. 2 qe_main: 5. 2 Terminating! rndis ----- Configures the NuttShell (nsh), enables a serial console on USART6 and enables RNDIS over USB. NSH commands:: nsh> mount -t procfs /proc nsh> ping -h Usage: ping [-c ] [-i ] [-W ] [-s ] ping -h Where: is either an IPv4 address or the name of the remote host that is requested the ICMPv4 ECHO reply. -c determines the number of pings. Default 10. -i is the default delay between pings (milliseconds). Default 1000. -W is the timeout for wait response (milliseconds). Default 1000. -s specifies the number of data bytes to be sent. Default 56. -h shows this text and exits. nsh> ping 10.42.0.1 PING 10.42.0.1 56 bytes of data 56 bytes from 10.42.0.1: icmp_seq=0 time=0.0 ms 56 bytes from 10.42.0.1: icmp_seq=1 time=0.0 ms ... 10 packets transmitted, 10 received, 0% packet loss, time 10100 ms rtt min/avg/max/mdev = 0.000/0.000/0.000/0.000 ms usbmsc ------ Configures the NuttShell (nsh), enables a serial console on USART6 and enables USB Mass Storage. NSH commands:: nsh> msconn mcsonn_main: Creating block drivers mcsonn_main: Configuring with NLUNS=1 mcsonn_main: handle=0x20004c10 mcsonn_main: Bind LUN=0 to /dev/mmcsd0 mcsonn_main: Connected nsh> msdis hcs04 ----- Configures the NuttShell (nsh) over USB Serial (check usbserial configuration) and enables ultrasonic sensor HC-SR04:: nsh> cat /dev/dist0 6241 --> value 6227 6241 6255 You can convert the value using following:: Convert to cm: value/58 Convert to inches: value/148 ssd1309 ------- This config is used to enable support to the transparent OLED display powered by SSD1309. The resolution of this display is 128x64 (although the effective view is 128x56). You can wire the display to your board this way: ======= ===== OLED PINS ======= ===== CS PB7 DC PB8 RESET PB6 SDA PA7 SCK PA5 ======= ===== The board profile configures the NSH over USB and you can use the fb command to test:: NuttShell (NSH) NuttX-12.5.1 nsh> fb VideoInfo: fmt: 0 xres: 128 yres: 64 nplanes: 1 PlaneInfo (plane 0): fbmem: 0x200034f8 fblen: 1024 stride: 16 display: 0 bpp: 1 Mapped FB: 0x200034f8 0: ( 0, 0) (128, 64) 1: ( 11, 5) (106, 54) 2: ( 22, 10) ( 84, 44) 3: ( 33, 15) ( 62, 34) 4: ( 44, 20) ( 40, 24) 5: ( 55, 25) ( 18, 14) Test finished nsh> telnetd ------- Configures the NuttShell (nsh), enables a serial console on USART6, enables RNDIS over USB and enables Device Configuration over Telnet. NSH commands:: nsh> mount -t procfs /proc nsh> ifcong Get the ip address assigned to eth0 and convert to hexadecimal, for example 192.168.1.2 becomes 0xC0A80102, than configure CONFIG_NETINIT_IPADDR and CONFIG_EXAMPLES_TELNETD_IPADDR, also configure the router address, in this example it woukd be 0xC0A80101. After theses changes rebuild and load the new firmware on your board:: nsh> mount -t procfs /proc nsh> telnetd At your host PC, telnet to IP address for the board:: $ telnet 192.168.01.02 Now you will be able to access the Device Configuration over Telnet:: Device Configuration over Telnet You can add functions to setup your device Type '?' and press for help cfg> ? Available commands: help, ? - show help reset - reset the board exit - exit shell max7219 ------- Configures the NuttShell (nsh) over USB Serial (check usbserial configuration) and enables LCD driver with MAX7219 for 8x8 LED matrix:: NuttShell (NSH) NuttX-12.5.1 nsh> nsh> nxhello nxhello_main: NX handle=0x20005420 nxhello_main: Set background color=0 nxhello_listener: Connected nxhello_main: Screen resolution (32,8) nxhello_hello: Position (3,0) nxhello_main: Disconnect from the server nsh> ======= ==== MAX7219 PINS ======= ==== CS PC4 DIN PA7 Clk PA5 ======= ==== As this LED matrix can be combined either horizontally or vetically, you can configure this using menuconfig:: Number of 8x8 LEDs matrices in the horizontal (width) Number of 8x8 LEDs matrices in the vertical (height) mfrc522 ------- Configures the NuttShell (nsh) over USB Serial (check usbserial configuration) and enables RFID driver with MFRC522:: nsh> rfid_readuid Trying to READ: Card is not present! Trying to READ: Card is not present! Trying to READ: RFID CARD UID = 0x3DB3F169 ======= ==== MFRC522 PINS ======= ==== SCK PA5 MISO PA6 MOSI PA7 CS PC5 ======= ==== The board used is based on MFRC522 NXP IC that supports contactless communication at 13.56 MHz and ISO/IEC 14443 A/MIFARE and NTAG. .. figure:: mfrc522_image.jpg :align: center bmp280 ------ Configures the NuttShell (nsh) over USB Serial (check usbserial configuration) and enables BMP280 Digital Pressure Sensor. BMP280 has an I2C address that can be configure by SDO. Connecting SDO to GND results in slave address 0x76, connection it to VDD results in slave address 0x77. This can be configured by enabling BMP280_I2C_ADDR_76 or BMP280_I2C_ADDR_77. This configuration uses I2C1 and slave address 0x77. NSH commands:: NuttShell (NSH) NuttX-12.6.0-RC1 nsh> bmp280 Absolute pressure [hPa] = 911.400024 Temperature [C] = 26.110001 nsh> bmp280 Absolute pressure [hPa] = 932.650024 Temperature [C] = 24.490000 There is a known issue where every time the sensor is initialized, the first measurement is wrong, please check https://github.com/apache/nuttx/issues/12421 for the latest updates on this issue.