Currently we make use of three SPI busses on a STM32F405. SPI1 is a slave and SPI 2/3 are masters. I switch SPI1 to master mode and it just doesn't work. I suspect the APB2 bus but I think I have it set correctly.

[MBish.1]

Here's my code:

SPI_HandleTypeDef spi_handle =
    {
        .Instance = DEF_SPI_INS_SPI1,
        .Init =
        {
            .Direction          = SPI_DIRECTION_2LINES,
            .BaudRatePrescaler  = SPI_BAUDRATEPRESCALER_2, 
            .CLKPhase           = SPI_PHASE_2EDGE,          
            .CLKPolarity        = SPI_POLARITY_HIGH,       
            .CRCCalculation     = SPI_CRCCALCULATION_DISABLE,
            .CRCPolynomial      = 0U, // unused
            .DataSize           = SPI_DATASIZE_8BIT,
            .FirstBit           = SPI_FIRSTBIT_MSB,
            .NSS                = SPI_NSS_SOFT,
            .TIMode             = SPI_TIMODE_DISABLE,
            .Mode               = SPI_MODE_MASTER
        }
    };
 
    HAL_StatusTypeDef return_code;
    return_code = HAL_SPI_Init(&spi_handle);
    uint8_t data[] = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08};
    uint8_t rx_data[16];
 
    HAL_SPI_Abort(&spi_handle);
    __HAL_SPI_ENABLE(&spi_handle);
    //return_code = HAL_SPI_Transmit(&spi_handle, data, 8, 5);
    return_code = HAL_SPI_TransmitReceive(&spi_handle, data, rx_data, 8, 100);
 
    while (HAL_SPI_GetState(&spi_handle) != HAL_SPI_STATE_READY);

return_code from HAL_SPI_Init() == HAL_OK

return code from HAL_SPI_TransmitReceive() == HAL_OK

I get past the while{} loop.

SPI register settings:

PIOA settings (pins 5 = SCLK, 6 = MOSI, 7 = MISO):

RCC register settings:

 

I've played around with the prescaler CLK phase and polarity. One note, CLK never idles HIGH with CPOL = SPI_POLARITY_HIGH.

What am I missing?

This is all I get when I am in master mode:

Also note, I am not wiggling a CS right now - just trying to see a CLK and some data.

When I build it in slave mode and send data to the chip I see nice wiggles in all the right places and the micro reads the data correctly and sends back data to the remote SPI master. When I am doing this mcu SPI master testing, I have the remote master device disconnected and just have the logic analyzer connected.

[waclawek.jan]

Are you sure you want SPI_CR1.BIDIMODE be set?

JW

[MBish.1]

I tried it again with that cleared, updated the image and still the same results.

[waclawek.jan]

OK so set SCK to GPIO Output and try to wiggle it "manually" and observe.

JW

[MBish.1]

I can't wiggle the old CLK and SDI. I can wiggle SDO.

[Bob S]

What external device is connected to the SPI signals? Is whatever used to be the master still connected? If so, it is probably driving those signals.

[MBish.1 · Accepted solution]

This was a hardware issue.