Electrical – STM32F103 SPI Pinout Problem

lorapinoutspistm32stm32cubemx

I am currently working on a project with LoRaWAN technology using STM32F103C8T6 microcontroller. For LoRa I am using SPI in Full-Duplex Master mode (spi1 specifically) and in CubeIDE when you activate SPI1, automatically pins PA5, PA6 and PA7 are activated (ver1):

However, PCB is designed and printed and those pins are unfortunately busy. Because, before it was planned to use other SPI1 pins (PB3, PB4, PB5) (ver2):

So, when I use ver1, all is good, LoRa connects to server and sends data without a problem. However, when I use ver2, it does not work at all. I debugged to find where is problem and found out that, SPI read fails (when version of LoRa is read, it returns 0). Thus, ASSERT fires and code is stuck in infinite loop. I could not find any reference of difference of SPI pins in the internet.

Can anyone explain the difference of these pins? And is it possible to use ver2? Thanks beforehand.

P.S. I am using HAL Library + LMIC library (for LoRa) and the configuration of SPI are the same for both ver1 and ver2. Here is code of configuration, if needed:

void MX_SPI1_Init(void)
{

  hspi1.Instance = SPI1;
  hspi1.Init.Mode = SPI_MODE_MASTER;
  hspi1.Init.Direction = SPI_DIRECTION_2LINES;
  hspi1.Init.DataSize = SPI_DATASIZE_8BIT;
  hspi1.Init.CLKPolarity = SPI_POLARITY_LOW;
  hspi1.Init.CLKPhase = SPI_PHASE_1EDGE;
  hspi1.Init.NSS = SPI_NSS_SOFT;
  hspi1.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_64;
  hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
  hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
  hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
  hspi1.Init.CRCPolynomial = 10;
  if (HAL_SPI_Init(&hspi1) != HAL_OK)
  {
    Error_Handler();
  }

}

Best Answer

After lots of tries, I found out that, remapped SPI1 does not work together with I2C1, because of I2C1-SMBA pin overlap with SP1 MOSI pin (PB5), even if you are not using SMBA. You can find about that here: STM32F103x8 errata chapter 2.8.7

So, I guess, I will use I2C2 for avoiding collision. The only change I should make on PCB would be redirecting I2C1 pins to I2C2 (2 pins), which is way better than redirecting SPI1 pins (3 pins) and other elements occupying ver1 (also 3) pins.

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Quite often on dev boards, some pins may be used by other functions on the board, such as a display, buttons, LEDs, etc. There are probably a bunch of solder bridges on the back of the board that serve to disconnect a pin on the microcontroller from the GPIO headers because when they are being used by something else on the board.

Take a look at the user manual and see if PA3 and PA4 are being used for some other function on the board. ST often includes the schematics for the dev board, and it should show the solder bridges on it as well.

Electrical – STM32F411 SPI slave enters debug infinite loop

This works in main of the master-board:

SPI2_MOSI (PC3) to SPI2_MOSI (PC3)
SPI2_NSS (PB12) to SPI2_NSS (PB12) 
SPI2_SCK (PB10) to SPI2_SCK (PB10)

Termainalprogram running on each PC connected to each board. Baud:115200, No-parity, CTS/RTS

void MX_NVIC_Init(void)
{
/* USART2_IRQn interrupt configuration */
HAL_NVIC_SetPriority(USART2_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(USART2_IRQn);
__HAL_UART_ENABLE_IT(&huart2,UART_IT_RXNE);

}

/* SPI2 init function */
void MX_SPI2_Init(void)
{
 hspi2.Instance = SPI2;
 hspi2.Init.Mode = SPI_MODE_MASTER;
 hspi2.Init.Direction = SPI_DIRECTION_2LINES;
 hspi2.Init.DataSize = SPI_DATASIZE_8BIT;
 hspi2.Init.CLKPolarity = SPI_POLARITY_HIGH;
 hspi2.Init.CLKPhase = SPI_PHASE_1EDGE;
 hspi2.Init.NSS = SPI_NSS_HARD_OUTPUT;
 hspi2.Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_32;
 hspi2.Init.FirstBit = SPI_FIRSTBIT_MSB;
 hspi2.Init.TIMode = SPI_TIMODE_DISABLE;
 hspi2.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
 hspi2.Init.CRCPolynomial = 10;
 HAL_SPI_Init(&hspi2);
 __HAL_SPI_ENABLE(&hspi2);
}


/* USART2 init function */
void MX_USART2_UART_Init(void)
{
 huart2.Instance = USART2;
 huart2.Init.BaudRate = 115200;
 huart2.Init.WordLength = UART_WORDLENGTH_8B;
 huart2.Init.StopBits = UART_STOPBITS_1;
 huart2.Init.Parity = UART_PARITY_NONE;
 huart2.Init.Mode = UART_MODE_TX_RX;
 huart2.Init.HwFlowCtl = UART_HWCONTROL_RTS;
 huart2.Init.OverSampling = UART_OVERSAMPLING_16;
 HAL_UART_Init(&huart2);
 __HAL_UART_HWCONTROL_RTS_ENABLE(&huart2);
}

On stm32f4xx_it.c for the master

void USART2_IRQHandler(void)
{
  HAL_UART_IRQHandler(&huart2);
  uint8_t data1;
  HAL_UART_Receive_IT(&huart2,&data1,sizeof(data1));
  data1++; //Icrementing 'A' to 'B'
  HAL_SPI_Transmit(&hspi2,&data1,  (uint16_t)sizeof(data1),HAL_MAX_DELAY);
 HAL_UART_Transmit(&huart2,&data1,(uint16_t)sizeof(data1),HAL_MAX_DELAY);//echoing back to PC
}

On the slave side in main

void MX_NVIC_Init(void)
{
 HAL_NVIC_SetPriority(SPI2_IRQn, 0, 0);
 HAL_NVIC_EnableIRQ(SPI2_IRQn);
 __HAL_SPI_ENABLE_IT(&hspi2, SPI_IT_RXNE);
 HAL_NVIC_SetPriority(USART2_IRQn, 0, 0);
 HAL_NVIC_EnableIRQ(USART2_IRQn);
 __HAL_UART_ENABLE_IT(&huart2,UART_IT_RXNE);
 __HAL_UART_HWCONTROL_RTS_ENABLE(&huart2);
}

/* SPI2 init function */
void MX_SPI2_Init(void)
{
 hspi2.Instance = SPI2;
 hspi2.Init.Mode = SPI_MODE_SLAVE;
 hspi2.Init.Direction = SPI_DIRECTION_2LINES_RXONLY;
 hspi2.Init.DataSize = SPI_DATASIZE_8BIT;
 hspi2.Init.CLKPolarity = SPI_POLARITY_HIGH;
 hspi2.Init.CLKPhase = SPI_PHASE_1EDGE;
 hspi2.Init.NSS = SPI_NSS_HARD_INPUT;
 hspi2.Init.FirstBit = SPI_FIRSTBIT_MSB;
 hspi2.Init.TIMode = SPI_TIMODE_DISABLE;
 hspi2.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
 hspi2.Init.CRCPolynomial = 10;
 HAL_SPI_Init(&hspi2);
 __HAL_SPI_ENABLE(&hspi2);
}


/* USART2 init function */
void MX_USART2_UART_Init(void)
{
  huart2.Instance = USART2;
  huart2.Init.BaudRate = 115200;
  huart2.Init.WordLength = UART_WORDLENGTH_8B;
  huart2.Init.StopBits = UART_STOPBITS_1;
  huart2.Init.Parity = UART_PARITY_NONE;
  huart2.Init.Mode = UART_MODE_TX_RX;
  huart2.Init.HwFlowCtl = UART_HWCONTROL_RTS;
  huart2.Init.OverSampling = UART_OVERSAMPLING_16;
  HAL_UART_Init(&huart2);
  __HAL_UART_HWCONTROL_RTS_ENABLE(&huart2);
}

In slave stm32f4xx_it.c

void SPI2_IRQHandler(void)
{
  HAL_SPI_IRQHandler(&hspi2);
 uint8_t data1;
 HAL_SPI_Receive_IT(&hspi2,&data1,sizeof(data1));
 HAL_UART_Transmit(&huart2,&data1,(uint16_t)sizeof(data1),HAL_MAX_DELAY);

}

void USART2_IRQHandler(void)
{
  HAL_UART_IRQHandler(&huart2);
  uint8_t data1;
  HAL_UART_Receive_IT(&huart2,&data1,sizeof(data1));
  data1++;
  HAL_UART_Transmit(&huart2,&data1,(uint16_t)sizeof(data1),HAL_MAX_DELAY);
}

Best Answer

Related Solutions

Electrical – Setting up PWM on PA.3 of the STM32F091RC Nucleo board

Electrical – STM32F411 SPI slave enters debug infinite loop

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