STM32f407 as SPI slave[HAL]
Posted on May 28, 2018 at 09:05
Im trying to catch data from the unknown device, this device has data and clock. I decided to make my stm32 as spi slave and catch the data as recevier.And im struggling with it. I have this data flow which i want to catch:
Clock is yellow and green is data.
I need only 16bytes from it, when data line goes low, we can see this 16bytes:
And there is the speed of the clock, as you can see its around 1.5us each clock pulse. So what i have to do is configure spi with HAL, i toolk SPI1(PA5 - CLOCK, PA7- DATA) cuz it has more powerful MHZ, chose spi mode ''RECEIVE ONLY SLAVE'', HARDWARE NSS SIGNAL: DISABLED. And here is my spi1 config:
static void MX_SPI1_Init(void)
{
/* SPI1 parameter configuration*/
hspi1.Instance = SPI1;
hspi1.Init.Mode = SPI_MODE_SLAVE;
hspi1.Init.Direction = SPI_DIRECTION_2LINES_RXONLY;
hspi1.Init.DataSize = SPI_DATASIZE_8BIT;
hspi1.Init.CLKPolarity = SPI_POLARITY_HIGH;
hspi1.Init.CLKPhase = SPI_PHASE_1EDGE;
hspi1.Init.NSS = SPI_NSS_SOFT;
hspi1.Init.FirstBit = SPI_FIRSTBIT_LSB;
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(__FILE__, __LINE__);
}
}
What im doing in main.c, as oscilo's pictures says we need to catch the moment when data goes low and then try to read a data, im trying to catch first pulse then wait until data goes high then low and only they read spi, at least only first byte - it should be 0.
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration----------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_DMA_Init();
MX_USB_DEVICE_Init();
MX_SPI1_Init();
/* USER CODE BEGIN 2 */
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
uint8_t collect_bits = 0;
char string_array[21] = {0};
uint8_t spi_buffer[16] ={0} ;
spi_buffer[0] = 5;
// while (1)
// {
// HAL_Delay(10000);
while (HAL_GPIO_ReadPin (GPIOA,GPIO_PIN_7) == 0){} // wait until GPIOC 9 goes high
while (HAL_GPIO_ReadPin (GPIOA,GPIO_PIN_7) == 1){} // wait until GPIOC 9 goes high
while (HAL_GPIO_ReadPin (GPIOA,GPIO_PIN_7) == 0){} // wait until GPIOC 9 goes high
while (HAL_GPIO_ReadPin (GPIOA,GPIO_PIN_7) == 1){} // wait until GPIOC 9 goes high
HAL_SPI_Receive(&hspi1, (uint8_t*)spi_buffer, 16,0);
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
// }
/* USER CODE END 3 */
}
And i catch nothing at all, my spi buffer all 16 bytes are 0. I tried SPI_DMA it changed only first byte on 0XFF. What am i doing wrong? Thanks
#stm32f4-spi #receive
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