Hello,
I'm a new new member and user of STM32 microcontrollers. I've just started using a bluepill STM32F103C8T6 microcontroller and I'm trying to set up a simple SPI communication.
At the moment I do not have slaves, only a master (the STM32), and I'm monitoring the MOSI pin with an oscilloscope. That MOSI pin is set low when inactive.
I've been trying for several days now to use the HAL_SPI_TRANSMIT function.
My code is simple:
- libraries & function definitions
- Running Init functions
- DaisyChain_Init => the piece of code I'm trying to fix
- Infinite loop with a blinking LED
I've managed to get my daisy chain function to work but for some reason (??) it only works with certain bytes. If I send 0x05, I can see the corresponding trace on my oscilloscope (00000101). If I send 0x88, I see 10001000 going through but then the MOSI pin stays high!
I have no idea why
Any help is welcome :)
#include "main.h"
#include "spi.h"
#include "gpio.h"
void SystemClock_Config(void);
void SPI1_EnableSlave(void);
void SPI1_DisableSlave(void);
void DaisyChain_Init(void);
int main(void)
{
HAL_Init();
SystemClock_Config();
MX_GPIO_Init();
MX_SPI1_Init();
DaisyChain_Init();
while (1)
{
// Turn on/off LED
HAL_GPIO_TogglePin(BP_LED_GPIO_Port, BP_LED_Pin);
// Delay in ms
HAL_Delay(100);
}
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
/** Initializes the CPU, AHB and APB busses clocks
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB busses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
{
Error_Handler();
}
}
void SPI1_EnableSlave()
{
// Set slave SS pin low
HAL_GPIO_WritePin(SPI1_CS_GPIO_Port, SPI1_CS_Pin, GPIO_PIN_RESET);
}
void SPI1_DisableSlave()
{
// Set slave SS pin high
HAL_GPIO_WritePin(SPI1_CS_GPIO_Port, SPI1_CS_Pin, GPIO_PIN_SET);
}
void DaisyChain_Init()
{
uint8_t SpiOutputBuffer;
SPI1_EnableSlave();
SpiOutputBuffer = 0x88;
HAL_SPI_Transmit(&hspi1, &SpiOutputBuffer, 1, 1);
SPI1_DisableSlave();
}
