RE: nRF52832 SAADC - modify values

Jared — Tue, 18 Feb 2020 11:57:02 GMT

Hi,

The data is stored in the buffer that p_buffer points to. You could modify the buffer but it will be overwritten after a new sample. I would instead recommend copying the buffer in the interrupt handler and save the current state in a variable. Then process the copied buffer in main context based on the saved state. You should avoid doing any time consuming tasks in the interrupt context as it could interfere with time critical operations such as the Softdevice.

void saadc_callback(nrf_drv_saadc_evt_t const * p_event)
{
    if (p_event->type == NRF_DRV_SAADC_EVT_DONE)
    {
        
        /*1. Set temp buffer to p_buffer
          2. Save state
          3. Set flag to indicate that buffer should be processed in main context*/
        
        memcpy(temp_buf, p_buffer, sizeof(p_buffer));
        state_var = state;
        flag = 1;
        
        
        ret_code_t err_code;
        err_code = nrf_drv_saadc_buffer_convert(p_event->data.done.p_buffer, SAMPLES_IN_BUFFER);
        APP_ERROR_CHECK(err_code);
        
    }
}




int main(void)
flag = 0;

{
    
    while(true)
    {
     if(flag == 1)
     {
        //add number to buffer based on state
        flag = 0;
     }
        
    }
    
}