How to add support to STM32F105?

[sinosoidal]

Hi,

How can I add support to the STM32F105? What are the necessary steps. Am I able to do it by myself?

I was tinkering with board and env bluepill_f103c8 and basic GPIO was working but as soon as I tried to work with UART I have stumbled in problems.

There are several versions of F105. I'm using F105R8. I don't know if that matters at all.

Other versions include: STM32F105R8, STM32F105V8, STM32F105RB, STM32F105VB, STM32F105RC, STM32F105VC

Thanks in advance!

[valeros]

As I can see the only framework you can use with F105 series is stm32cube, but you'll need to manually add your custom board to the ststm32 platform.

[brightproject]

Good day @sinosoidal and @valeros 🙂 I have a board with a STM32F105RCT6 microcontroller

Making some attempts to add it to .pio For this, I created a genericSTM32F105RC.json file with the following contents

{
  "build": {
    "core": "stm32",
    "cpu": "cortex-m3",
    "extra_flags": "-DSTM32F105xC -DSTM32F1",
    "f_cpu": "72000000L",
    "hwids": [
      [
        "0x1EAF",
        "0x0003"
      ],
      [
        "0x1EAF",
        "0x0004"
      ]
    ],
    "mcu": "stm32f105rct6",
    "product_line": "STM32F105xC",
    "variant": "STM32F1xx/F105R(8-B-C)T"
  },
  "debug": {
    "jlink_device": "STM32F105RC",
    "openocd_target": "stm32f1x",
    "svd_path": "STM32F107.svd"
  },
  "frameworks": [
    "arduino",
    "cmsis",
    "libopencm3",
    "stm32cube"
  ],
  "name": "STM32F105RC (64k RAM. 256k Flash)",
  "upload": {
    "disable_flushing": false,
    "maximum_ram_size": 65536,
    "maximum_size": 262144,
    "protocol": "stlink",
    "protocols": [
      "jlink",
      "cmsis-dap",
      "stlink",
      "blackmagic",
      "serial",
      "dfu"
    ],
    "require_upload_port": true,
    "use_1200bps_touch": false,
    "wait_for_upload_port": false
  },
  "url": "https://www.st.com/en/microcontrollers-microprocessors/stm32f105rc.html",
  "vendor": "Generic"
}

Data was partially taken from the boards_entry.txt file, which is located in the archive below.

The JSON file was placed in the folder

.platformio\platforms\ststm32\boards

Further in the folder

.platformio\packages\framework-arduinoststm32\variants\STM32F1xx

I found a variant for F105R(8-B-C)T and added there the linker ldscript.ld from the board stm32f103 Archive attached:

F105R(8-B-C)T.zip

platformio.ini is like this:

[platformio] description = Testing board on STM32F105RCT6 default_envs = STM32F105RCT6

[env:STM32F105RCT6] platform = ststm32 board = genericSTM32F105RC framework = arduino

#include <Arduino.h>

#define LED_UART1 (PA8)

#define BAUD_RATE 115200 // bitrate or baudrate ~ 100 kHz

#define UART1_SERIAL_TX (PA9)
#define UART1_SERIAL_RX (PA10)

#define UART2_SERIAL_TX (PC10)
#define UART2_SERIAL_RX (PC11)

// Initialize serial port
HardwareSerial PORT1(USART1);
HardwareSerial PORT2(UART4);

void setup() {
 
    // initialize the pin to output
    pinMode (LED_UART1, OUTPUT);
    
    // set level on pin to 0
    digitalWrite (LED_UART1, LOW);
    
    // Start the serial port for monitoring and data transfer
    PORT1.setTx(UART1_SERIAL_TX);
    PORT1.setRx(UART1_SERIAL_RX);
    PORT1.begin(BAUD_RATE); // PA9, PA10
    
    PORT2.setTx(UART2_SERIAL_TX);
    PORT2.setRx(UART2_SERIAL_RX);
    PORT2.begin(BAUD_RATE); // PC10, PC11
    
    PORT1.println("UART1");
    PORT2.println("UART4");

} // SETUP

void loop() {

    digitalWrite(LED_UART1, HIGH);
    delay(200); 
    digitalWrite(LED_UART1, LOW);
    delay(200);  

} // LOOP

The code compiles without errors, there is a warning about SystemClock_Config

Compiling .pio\build\STM32F105RCT6\FrameworkArduinoVariant\generic_clock.c.o .platformio\packages\framework-arduinoststm32\variants\STM32F1xx\F105R(8-B-C)T\generic_clock.c: In function 'SystemClock_Config': .platformio\packages\framework-arduinoststm32\variants\STM32F1xx\F105R(8-B-C)T\generic_clock.c:24:2: warning: #warning "SystemClock_Config() is empty. Default clock at reset is used." [-Wcpp] 24 | #warning "SystemClock_Config() is empty. Default clock at reset is used."

At first I didn't give much attention to the warning, because the firmware controlled the LED and Serial gave out data, but when I needed to output data to UART2 or UART4 and use the CAN or MODBUS I realized that they were not working. Then I looked at the generic_clock.c file and saw, that it is empty.

WEAK void SystemClock_Config(void)
{
  /* SystemClock_Config can be generated by STM32CubeMX */
#warning "SystemClock_Config() is empty. Default clock at reset is used."
}

I also understood from the datasheet that an internal generator is needed for the pins and UART1, in order for other peripherals to work, an external quartz generator must be configured.

Tried to copy the contents of the generic_clock.c file from other boards, but it didn't help. Also studied the material from another framework

https://github.com/stm32duino/Arduino_Core_STM32/wiki/Add-a-new-variant-(board)#4---system-clock-configuration

But it didn't help either and would appreciate any help.

[brightproject]

Put this code in here

.platformio\packages\framework-arduinoststm32\variants\STM32F1xx\F105R(8-B-C)T\generic_clock.c

/*
 *******************************************************************************
 * Copyright (c) 2020-2021, STMicroelectronics
 * All rights reserved.
 *
 * This software component is licensed by ST under BSD 3-Clause license,
 * the "License"; You may not use this file except in compliance with the
 * License. You may obtain a copy of the License at:
 *                        opensource.org/licenses/BSD-3-Clause
 *
 *******************************************************************************
 */
#if defined(ARDUINO_GENERIC_F105R8TX) || defined(ARDUINO_GENERIC_F105RBTX) || defined(ARDUINO_GENERIC_F105RCTX)
#include "pins_arduino.h"

/**
  * @brief  System Clock Configuration
  * @param  None
  * @retval None
  */
// WEAK void SystemClock_Config(void)
// {
//   /* SystemClock_Config can be generated by STM32CubeMX */
// #warning "SystemClock_Config() is empty. Default clock at reset is used."
// }

WEAK void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
  RCC_OscInitStruct.PLL2.PLL2State = RCC_PLL_NONE;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure the Systick interrupt time
  */
  __HAL_RCC_PLLI2S_ENABLE();
}

#endif /* ARDUINO_GENERIC_* */