maggu2810

stm32f4-discovery

First steps on my first STM32 project

Author: Markus Rathgeb

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Create Project - STM32CubeMX

• STM32CubeMX
• Select board
• use default configuration for peripherals
• Project Manager
  • Project Settings
    • Project Name: stm32-first-steps
    • Project Location: /.../project/parent/directory/
    • Toolchain / IDE: STM32CubeIDE
    • Generate Under Root: enabled
• Open “ioc” file in CLion
• Open as Project
• Open with STM32CubeMX
  • Generate Code
  • Close STM32CubeMX
• OpenOCD Dialog
  • Select Board Configuration File
  • stm32f4discovery.cfg
  • Use
• New, File, .gitignore: JetBrains.gitignore

Update Heap / Stack Size

• Project Manager
  • Linker Settings:
    • Minimum Heap Size: 0x400 (before 0x200)
    • Minimum Stack Size: 0x800 (before 0x400)

UART printf

Code

• Open ioc file in STM32CubeMX
  • Connectivity
    • USART2
      • Mode
        • Mode: Asynchronous
        • HArdware Flow Control (RS232): Disable
      • Parameter Setting
        • Basic Parameters
          • Baud Rate: 115200 Bits/s
          • Word Length: 8 Bits (including Parity)
          • Parity: None
          • Stop Bits: 1
        • Advanced Parameters
          • Data Direction: Receive and Transmit
          • Over Sampling: 16 Samples
  • Generate Code
• Edit Core/Src/main.c

/* USER CODE BEGIN 0 */

int __io_putchar(int ch)
{
  HAL_UART_Transmit(&huart2, (uint8_t *)&ch, 1, 0xFFFF);
  return ch;
}

/* USER CODE END 0 */

Wiring

Connect FTDI / Prolific / …

Cable Type	RXD	TXD	GND
black, yellow, orange	orange	yellow	black
black, white, green	green	white	black

• RXD: PA3
• TXD: PA2
• GND: GND

Host Side

It seems screen and minicom do not adding a carriage return on a line feed default. This result into a new line without beginning at the beginning of the line but continue new data on the next position.

For minicom we could edit ~/.minirc.dfl and add the following line

pu addcarreturn Yes

minicom could be started using (change the device):

minicom -b 115200 -D /dev/ttyUSB2 -o

Lecture

See also:

• https://community.st.com/s/question/0D53W00001NvW0ZSAV/stm32g0-redirect-printf-to-write-and-use-uart-how-to
• https://deepbluembedded.com/stm32-debugging-with-uart-serial-print/

LED Test

   <3>
<4>   <5>
   <6>

• LED3: orange
• LED4: green
• LED5: red
• LED6: blue

main.c main loop (heartbeet)

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  uint32_t tickLast = HAL_GetTick();
  int next_action = GPIO_PIN_SET;
  while (1)
  {
    /* USER CODE END WHILE */
    MX_USB_HOST_Process();

    /* USER CODE BEGIN 3 */
    const uint32_t tickCur = HAL_GetTick();
    if (tickCur - tickLast >= 1000) {
      tickLast = tickCur;
      HAL_GPIO_WritePin(GPIOD, LD4_Pin, next_action);
      next_action = next_action == GPIO_PIN_SET ? GPIO_PIN_RESET : GPIO_PIN_SET;
    }
  }
  /* USER CODE END 3 */

main.c error handler

void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */
  __disable_irq();
  uint32_t tickLast = HAL_GetTick();
  int next_action = GPIO_PIN_SET;
  while (1)
  {
    const uint32_t tickCur = HAL_GetTick();
    if (tickCur - tickLast >= 500)
    {
      tickLast = tickCur;
      HAL_GPIO_WritePin(GPIOD, LD6_Pin, next_action);
      next_action = next_action == GPIO_PIN_SET ? GPIO_PIN_RESET : GPIO_PIN_SET;
    }
  }
  /* USER CODE END Error_Handler_Debug */
}

USB Host

Very import VBUS fix

USB_HOST/Target/usbh_platform.c

• on state == 0 change from GPIO_PIN_RESET to GPIO_PIN_SET
• otherwise (1) change from GPIO_PIN_SET to GPIO_PIN_RESET

Fixed code looks like:

void MX_DriverVbusFS(uint8_t state)
{
  uint8_t data = state;
  /* USER CODE BEGIN PREPARE_GPIO_DATA_VBUS_FS */
  if(state == 0)
  {
    /* Drive high Charge pump */
    data = GPIO_PIN_SET;
  }
  else
  {
    /* Drive low Charge pump */
    data = GPIO_PIN_RESET;
  }
  /* USER CODE END PREPARE_GPIO_DATA_VBUS_FS */
  HAL_GPIO_WritePin(GPIOC,GPIO_PIN_0,(GPIO_PinState)data);
}

For further information see the end of: http://evenlund.blogspot.com/2016/10/usb-storage-with-stm32f4-discovery-and_58.html

CAN Bus

Configuration

Parameter Settings

For the “CAN bit-timing” values’ calculation you can use CAN Bit Time Calculation

• ST Microelectronics bxCAN
• Clock Rate: 42 MHz
• Sample-Point: 87.5 %
• SJW: 1

STM32 CubeMX Configuration

• Bit Timing Parameters
  • Prescaler (for Time Quantum): 6
  • Time Quantum: 142.8571… ns
  • Time Quanta in Bit Segment 1: 11 Times
  • Time Quanta in Bit Segment 2: 2 Time
  • Time for one Bit: 2000 ns
  • Baud Rate: 500000 bit/s
  • ReSynchronization Jump Width: 1 Time
• Basic Parameters
  • Time Triggered Communication Mode: Disable
  • Automatic Bus-Off Management: Disable
  • Automatic Wake-Up Mode: Disable
  • Automatic Retransmission: Enable
  • Receive Fifo Locked Mode: Disable
  • Transmit Fifo Priority: Disable
• Advanced Parameters
  • Operating Mode: Normal

GPIO Settings

PIN Name	Signal on PIN	GPIO output level	GPIO mode	GPIO Pull-up/Pull-down	Maximum output speed
PD0	CAN1_RX	n/a	Alternate Function Push Pull	Pull-up	Very High
PD1	CAN1_TX	n/a	Alternate Function Push Pull	Pull-up	Very High