Issue in SPI DMA Communication: Command Reception Not Triggering on Slave Side

[Praveen_S268]

I am working on SPI communication fullduplex using DMA between two Nucleo boards:

Master: Nucleo-U083RC
Slave: Nucleo-U575ZI

Implementation:

Slave Side:
The slave continuously transmits integer data values like 100000, 100001, 100002, and so on, using the normal method: HAL_SPI_Transmit().

Master Side:
The master receives this data using SPI DMA: HAL_SPI_Receive_DMA().

Command Handling:
After the master receives every 200 data values, it sends a command to the slave using HAL_SPI_Transmit_DMA().
On the slave side, this command is expected to be received with high priority using the interrupt method: HAL_SPI_Receive_IT().
Once the slave receives the command, it changes the data it is transmitting to new values, starting from 200000, 200001, 200002, and so on.

Master Response:
The master receives this updated data using HAL_SPI_Receive_DMA().

Issue:
The problem I’m facing is that when the master sends the command using HAL_SPI_Transmit_DMA(), the slave does not receive the command via HAL_SPI_Receive_IT().
I have verified on the master side that the command is transmitted successfully because the state is not busy, and the function returns HAL_OK.

Master Initialization Code:

static void MX_SPI1_Init(void)
{

/* USER CODE BEGIN SPI1_Init 0 */

/* USER CODE END SPI1_Init 0 */

/* USER CODE BEGIN SPI1_Init 1 */

/* USER CODE END SPI1_Init 1 */
/* SPI1 parameter configuration*/
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_8;
hspi1.Init.FirstBit = SPI_FIRSTBIT_MSB;
hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
hspi1.Init.CRCPolynomial = 7;
hspi1.Init.CRCLength = SPI_CRC_LENGTH_DATASIZE;
hspi1.Init.NSSPMode = SPI_NSS_PULSE_ENABLE;
if (HAL_SPI_Init(&hspi1) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN SPI1_Init 2 */

/* USER CODE END SPI1_Init 2 */

}

Slave Initialization Code:

static void MX_SPI1_Init(void)
{

/* USER CODE BEGIN SPI1_Init 0 */

/* USER CODE END SPI1_Init 0 */

SPI_AutonomousModeConfTypeDef HAL_SPI_AutonomousMode_Cfg_Struct = {0};

/* USER CODE BEGIN SPI1_Init 1 */

/* USER CODE END SPI1_Init 1 */
/* SPI1 parameter configuration*/
hspi1.Instance = SPI1;
hspi1.Init.Mode = SPI_MODE_SLAVE;
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.FirstBit = SPI_FIRSTBIT_MSB;
hspi1.Init.TIMode = SPI_TIMODE_DISABLE;
hspi1.Init.CRCCalculation = SPI_CRCCALCULATION_DISABLE;
hspi1.Init.CRCPolynomial = 0x7;
hspi1.Init.NSSPMode = SPI_NSS_PULSE_DISABLE;
hspi1.Init.NSSPolarity = SPI_NSS_POLARITY_LOW;
hspi1.Init.FifoThreshold = SPI_FIFO_THRESHOLD_01DATA;
hspi1.Init.MasterSSIdleness = SPI_MASTER_SS_IDLENESS_00CYCLE;
hspi1.Init.MasterInterDataIdleness = SPI_MASTER_INTERDATA_IDLENESS_00CYCLE;
hspi1.Init.MasterReceiverAutoSusp = SPI_MASTER_RX_AUTOSUSP_DISABLE;
hspi1.Init.MasterKeepIOState = SPI_MASTER_KEEP_IO_STATE_DISABLE;
hspi1.Init.IOSwap = SPI_IO_SWAP_DISABLE;
hspi1.Init.ReadyMasterManagement = SPI_RDY_MASTER_MANAGEMENT_INTERNALLY;
hspi1.Init.ReadyPolarity = SPI_RDY_POLARITY_HIGH;
if (HAL_SPI_Init(&hspi1) != HAL_OK)
{
Error_Handler();
}
HAL_SPI_AutonomousMode_Cfg_Struct.TriggerState = SPI_AUTO_MODE_DISABLE;
HAL_SPI_AutonomousMode_Cfg_Struct.TriggerSelection = SPI_GRP1_GPDMA_CH0_TCF_TRG;
HAL_SPI_AutonomousMode_Cfg_Struct.TriggerPolarity = SPI_TRIG_POLARITY_RISING;
if (HAL_SPIEx_SetConfigAutonomousMode(&hspi1, &HAL_SPI_AutonomousMode_Cfg_Struct) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN SPI1_Init 2 */

/* USER CODE END SPI1_Init 2 */

}

Attached Code:
I have attached the master and slave programs. Can someone help me identify the issue or suggest a solution?

[Andrew Neil]

Welcome to the forum.

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@Praveen_S268 wrote:

I am working on SPI communication fullduplex using DMA between two Nucleo boards:

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I'd suggest that you get it working first without DMA.

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@Praveen_S268 wrote:

The slave continuously transmits integer data values like 100000, 100001, 100002, and so on, using the normal method: HAL_SPI_Transmit().

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That's not how SPI works.

The Master is the one which generates the clock - so the slave cannot just transmit on its own.

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@Praveen_S268 wrote:

I have verified on the master side that the command is transmitted successfully because the state is not busy, and the function returns HAL_OK.

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That's necessary - but not sufficient.

There could be hardware and/or configuration issues meaning that the software "works" internally, but the external communication doesn't happen (correctly).

That's why it's important to post your schematic - showing the connections between the boards.

And to use an oscilloscope or logic analyser to check what's actually happening on the wires...