Question about SPI transaction manager

RE: Question about SPI transaction manager

Daniel — Thu, 23 Nov 2017 08:15:11 GMT

It's clear! Thank you, Jakub! Appreciated!

RE: Question about SPI transaction manager

Jakub Rzeszutko — Thu, 23 Nov 2017 08:07:04 GMT

You can always use it. This macro is changed to "const" if you are not using EasyDMA or it is empty if you are using EasyDMA.

Here is definition:

#ifndef NRF_SPI_MNGR_BUFFERS_IN_RAM
  #define NRF_SPI_MNGR_BUFFERS_IN_RAM defined(SPIM_PRESENT)  // SPIM_PRESENT == EasyDMA present
#endif

#if NRF_SPI_MNGR_BUFFERS_IN_RAM
  #define NRF_SPI_MNGR_BUFFER_LOC_IND
#else
  #define NRF_SPI_MNGR_BUFFER_LOC_IND const
#endif

RE: Question about SPI transaction manager

Daniel — Thu, 23 Nov 2017 08:00:35 GMT

Thanks! It works! Another question is, there are some prefix declarations in the st7565LCD.c file, like

static NRF_SPI_MNGR_BUFFER_LOC_IND uint8_t m_command_buffer[]

So what is the NRF_SPI_MNGR_BUFFER_LOC_IND? And when should we use that?

RE: Question about SPI transaction manager

Jakub Rzeszutko — Thu, 23 Nov 2017 07:47:24 GMT

As I suspected problem was with data location. When you are using function nrf_spi_mngr_schedule you need to:

Always ensure that data will not change after leaving function nrf_spi_mngr_schedule
Ensure that data is in RAM area when you are using EasyDMA mode.

You need to correct your main file. Change:

static void read_accl_info(void)
{
    ret_code_t ret_val;
    uint8_t tx_cmd[] = {0x8F, 0xFF};

    nrf_spi_mngr_transfer_t transfer = 
        NRF_SPI_MNGR_TRANSFER(tx_cmd, sizeof(tx_cmd), rx_data, sizeof(rx_data));

    nrf_spi_mngr_transaction_t trans = 
    {
        .begin_callback      = accl_spi_transfer_begin_cb,
        .end_callback        = accl_spi_transfer_done_cb,
        .p_user_data         = NULL,
        .p_transfers         = &transfer,
        .number_of_transfers = 1,
        .p_required_spi_cfg  = NULL
    };

    ret_val = nrf_spi_mngr_schedule(&m_nrf_spi_mngr, &trans);
    APP_ERROR_CHECK(ret_val);
}

To:

uint8_t m_tx_cmd[] = {0x8F, 0xFF};  // global variable to initialize static variable: transfer

static void read_accl_info(void)
{
    ret_code_t ret_val;

    // static - data in RAM and it will not change during transfer
    static nrf_spi_mngr_transfer_t transfer = 
        NRF_SPI_MNGR_TRANSFER(m_tx_cmd, sizeof(m_tx_cmd), rx_data, sizeof(rx_data));

    static nrf_spi_mngr_transaction_t const trans = 
    {
        .begin_callback      = accl_spi_transfer_begin_cb,
        .end_callback        = accl_spi_transfer_done_cb,
        .p_user_data         = NULL,
        .p_transfers         = &transfer,
        .number_of_transfers = 1,
        .p_required_spi_cfg  = NULL
    };

    ret_val = nrf_spi_mngr_schedule(&m_nrf_spi_mngr, &trans);
    APP_ERROR_CHECK(ret_val);
}

RE: Question about SPI transaction manager

Daniel — Thu, 23 Nov 2017 07:26:46 GMT

Hi Jakub, I upload my main.c at the end of the question. Just copy /examples/peripheral/spi_master_using_nrf_spi_mngr project and replace the main.c file in the folder. Only a few changes to the original project main.

RE: Question about SPI transaction manager

Jakub Rzeszutko — Thu, 23 Nov 2017 07:02:22 GMT

It is hard to guess. Please maybe share a source how you use this nrf_pwr_mgmt_run function.

Regarding your first case I was asking about SPI/SPIM because when using SPIM (EasyDMA) you cannot have "const" transfer variable. All data needs to be in RAM. Your declaration shall be like:

static nrf_spi_mngr_transfer_t transfer[] = 
{
    NRF_SPI_MNGR_TRANSFER(tx_cmd, sizeof(tx_cmd), &rx_data, sizeof(rx_data))
};

RE: Question about SPI transaction manager

Daniel — Thu, 23 Nov 2017 02:32:14 GMT

OK, after some tests, if I comment

     nrf_pwr_mgmt_run();

In the while loop in main function, the spi_manager will go to the end callback, but if the power_mgmt exists, it will not go to the end callback, why?

RE: Question about SPI transaction manager

Daniel — Thu, 23 Nov 2017 02:16:09 GMT

Well, it seems that I send the wrong command. I use the spi_manager example to make a test, send the right command "tx_cmd[] = {0x8F, 0xFF}", then I get the correct who_am_i register value. However, I find that the callback function doesn't work, even if I put a breakpoint in it.

RE: Question about SPI transaction manager

Daniel — Thu, 23 Nov 2017 01:33:47 GMT

yes, I turned on the SPI and SPIM2, also tried EasyDMA on and off state, but it leads to the same result.

RE: Question about SPI transaction manager

Jakub Rzeszutko — Wed, 22 Nov 2017 11:32:16 GMT

Do you use SPI or SPIM (do you use EasyDMA) ?