Interface SCL3300 with STM32H7

[sundar_]

Hello,

I am trying to interface STM32H7 microcontroller with SCL3300 inclinometer, I have attached the SPI configuration and the SPItransfer method.

ConfigSPI_SCL3300()
{

	// 52  PA6  SPI1_MISO
	// 151 PD7  SPI1_MOSI
	// 154 PG11 SPI1_SCK
        // 153 PG10 SPI_CS


	LL_AHB4_GRP1_EnableClock(LL_AHB4_GRP1_PERIPH_GPIOA);
	LL_AHB4_GRP1_EnableClock(LL_AHB4_GRP1_PERIPH_GPIOD);
	LL_AHB4_GRP1_EnableClock(LL_AHB4_GRP1_PERIPH_GPIOG);
	//LL_AHB4_GRP1_EnableClock(LL_AHB4_GRP1_PERIPH_GPIOC);
	LL_APB2_GRP1_EnableClock(LL_APB2_GRP1_PERIPH_SPI1);

	LL_RCC_HSI_Enable();
	LL_RCC_SetCLKPClockSource(LL_RCC_CLKP_CLKSOURCE_HSI);
	LL_RCC_SetSPIClockSource(LL_RCC_SPI123_CLKSOURCE_CLKP);

	LL_GPIO_InitTypeDef  GPIO_InitStruct;

	/* SPI1 SCK GPIO pin configuration for PG11 */
	GPIO_InitStruct.Pin = LL_GPIO_PIN_11;
	GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
	GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
	GPIO_InitStruct.Pull = LL_GPIO_PULL_DOWN;
	GPIO_InitStruct.Speed = LL_GPIO_SPEED_HIGH;
	GPIO_InitStruct.Alternate = LL_GPIO_AF_5;
	LL_GPIO_Init(GPIOG, &GPIO_InitStruct);

	/* SPI1 MISO GPIO pin configuration for PA6 */
	GPIO_InitStruct.Pin = LL_GPIO_PIN_6;
	GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
	GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
	GPIO_InitStruct.Pull = LL_GPIO_PULL_DOWN;
	GPIO_InitStruct.Speed = LL_GPIO_SPEED_HIGH;
	GPIO_InitStruct.Alternate = LL_GPIO_AF_5;
	LL_GPIO_Init(GPIOA, &GPIO_InitStruct);

	/* SPI1 MOSI GPIO pin configuration for PD7 */
	GPIO_InitStruct.Pin = LL_GPIO_PIN_7;
	GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
	GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
	GPIO_InitStruct.Pull = LL_GPIO_PULL_DOWN;
	GPIO_InitStruct.Speed = LL_GPIO_SPEED_HIGH;
	GPIO_InitStruct.Alternate = LL_GPIO_AF_5;
	LL_GPIO_Init(GPIOD, &GPIO_InitStruct);

	/* SPI1 CS GPIO pin configuration for PG10 */
	GPIO_InitStruct.Pin = LL_GPIO_PIN_10;
	GPIO_InitStruct.Mode = LL_GPIO_MODE_OUTPUT;       // software controlled
	GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
	GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;           // idle = high
	GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_VERY_HIGH;
	LL_GPIO_Init(GPIOG, &GPIO_InitStruct);

	///* SPI1 MUX S GPIO pin configuration for PC8 */
	//GPIO_InitStruct.Pin = LL_GPIO_PIN_8;
	//GPIO_InitStruct.Mode = LL_GPIO_MODE_OUTPUT;       
	//GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
	//GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;           
	//GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_LOW;
	//LL_GPIO_Init(GPIOC, &GPIO_InitStruct);

	//LL_GPIO_ResetOutputPin(GPIOC, LL_GPIO_PIN_8); // MUX S low for SPI mode

	//Config SPI Master:
	LL_SPI_Disable(SPI1);
	LL_SPI_DeInit(SPI1);

	/* Configure the SPI1 parameters */
	LL_SPI_InitTypeDef   SPI_InitStruct;
	SPI_InitStruct.BaudRate = LL_SPI_BAUDRATEPRESCALER_DIV8; /* from div128 to div4 which 4Mhz recommended operating range */
	SPI_InitStruct.TransferDirection = LL_SPI_FULL_DUPLEX; // no wait between send and rx data
	SPI_InitStruct.ClockPhase = LL_SPI_PHASE_1EDGE; /* SPI MODE 0 */
	SPI_InitStruct.ClockPolarity = LL_SPI_POLARITY_LOW; /* SPI MODE 0 */
	SPI_InitStruct.BitOrder = LL_SPI_MSB_FIRST;
	SPI_InitStruct.DataWidth = LL_SPI_DATAWIDTH_32BIT; /* 32 bit frame */
	SPI_InitStruct.NSS = LL_SPI_NSS_SOFT;
	SPI_InitStruct.CRCCalculation = LL_SPI_CRCCALCULATION_DISABLE;
	SPI_InitStruct.CRCPoly = 10;
	SPI_InitStruct.Mode = LL_SPI_MODE_MASTER;

	LL_SPI_Init(SPI1, &SPI_InitStruct);

	LL_SPI_SetStandard(SPI1, LL_SPI_PROTOCOL_MOTOROLA); 
	LL_SPI_SetTransferSize(SPI1, 0);
	LL_SPI_Enable(SPI1);

	LL_GPIO_SetOutputPin(GPIOG, LL_GPIO_PIN_10);
}

		uint32_t AccelerometerService_SCL3300::SPITransfer32(uint32_t val)
		{
			uint32_t ret{};

			LL_GPIO_ResetOutputPin(GPIOG, LL_GPIO_PIN_10);
			//GlobalTimer_Sleep_us(10);

			LL_SPI_ClearFlag_SUSP(SPI1);
			LL_SPI_StartMasterTransfer(SPI1);

			while (!LL_SPI_IsActiveFlag_TXP(SPI1));
			LL_SPI_TransmitData32(SPI1, val);

			while (!LL_SPI_IsActiveFlag_RXP(SPI1));
			ret = LL_SPI_ReceiveData32(SPI1);

			while (!LL_SPI_IsActiveFlag_TXC(SPI1));

			//LL_SPI_SuspendMasterTransfer(SPI1);
			//while (!LL_SPI_IsActiveFlag_SUSP(SPI1));

			
			LL_GPIO_SetOutputPin(GPIOG, LL_GPIO_PIN_10);
			GlobalTimer_Sleep_us(10); /* Sleep 10us */
			//NanoSleep::nanosleep(10000);

			return ret;
		}

 I am trying to send WHOAMI twice and when I look at the second frame my CRC almost always fails. If anyone can highlight why my CRC fails.

Attaching screenshot of my logic analyzer. CS, SCK, MOSI , MISO respectively. 

Thank you

[Andrew Neil]

---

@sundar_ wrote:

my CRC almost always fails.

---

Are you sure you are using the correct CRC (with correct initialisation), as described in the Murata datasheet?

https://www.murata.com/-/media/webrenewal/products/sensor/pdf/datasheet/datasheet_scl3300-d01.ashx?la=en&cvid=20231213062930000000#page=26

via: https://www.murata.com/en-eu/products/sensor/inclinometer/overview/lineup/scl3300

Have you tried using the C implementation which they provide?

[sundar_]

Yes I am using the same implementation that is in the datasheet

/* Calculate CRC was taken from SCL3300 datasheet */
uint8_t AccelerometerService_SCL3300::CalculateCRC(uint32_t Data)
{
	uint8_t BitIndex;
	uint8_t BitValue;
	uint8_t crcVal;
	crcVal = 0xFF;
	for (BitIndex = 31; BitIndex > 7; BitIndex--)
	{
		BitValue = (uint8_t)((Data >> BitIndex) & 0x01);
		crcVal = CRC8(BitValue, crcVal);
	}
	crcVal = (uint8_t)~crcVal;
	return crcVal;
}

uint8_t AccelerometerService_SCL3300::CRC8(uint8_t BitValue, uint8_t crcVal)
{
	uint8_t Temp;
	Temp = (uint8_t)(crcVal & 0x80);
	if (BitValue == 0x01)
	{
		Temp ^= 0x80;
	}
	crcVal <<= 1;
	if (Temp > 0)
	{
		crcVal ^= 0x1D;
	}
	return crcVal;
}
		bool AccelerometerService_SCL3300::CheckCRC(uint32_t frame)
		{
			uint8_t rx_crc = (uint8_t)(frame & 0x000000FFu);
			//uint32_t MSB_31_8 = frame & 0xFFFFFF00u;
			uint8_t calc_crc = CalculateCRC(frame);
			return (rx_crc == calc_crc);
		}