nRF52 I2S Datahandler to buffer save.

[Empe]

hello Everyone

i Need help to Use nRF52840 DK - I2S 

Now i can play music use I2S "realtime"

it means when i was Play music front of mic and then i can hear that music to speaker.

so in this time i want to record the sound and play it after some trigger accrued

but i don't know how to save mic input data to Ram Buffer.

here is my part of code - almost same "SDK14.0 I2S Example Data_handler"

when i use that data handler code.. i can play sound real-time

//////////////////////////////////////////////////////////////////////////////////////////////////////

static void data_handler(nrf_drv_i2s_buffers_t const * p_released, uint32_t status)
{
      ASSERT(p_released);

      if (!(status & NRFX_I2S_STATUS_NEXT_BUFFERS_NEEDED))
      {
            return;
      }

      if (!p_released->p_rx_buffer)
      {
            nrf_drv_i2s_buffers_t const next_buffers =

            {
                  .p_rx_buffer = m_buffer_rx[1],
                  .p_tx_buffer = m_buffer_tx[1],
            };
            APP_ERROR_CHECK(nrf_drv_i2s_next_buffers_set(&next_buffers));

            mp_block_to_check = m_buffer_rx[1];
            mp_block_to_fill = m_buffer_tx[1];
            Count = 0;

      }
      else
      {
            mp_block_to_check = p_released->p_rx_buffer;
            APP_ERROR_CHECK(nrf_drv_i2s_next_buffers_set(p_released));
            mp_block_to_fill = (uint32_t *)p_released->p_tx_buffer;

            NRF_I2S->RXD.PTR = (uint32_t)&pcm_samples[Count];
            NRF_LOG_INFO("Rx - Index:%d, Rx - Vel:0x%08x ", Count, pcm_samples[Count]); //Count, mp_block_to_check);//Count, pcm_samples[Count]);
            NRF_I2S->TXD.PTR = (uint32_t)&pcm_samples[Count - 300];
            NRF_LOG_INFO("Tx - Index:%d, Tx - Vel:0x%08x ", Count, pcm_samples[Count]);

      }

}

//////////////////////////////////////////////////////////////////////////////////////////////////////

but i want do record and play that sound after so change some part of code...

//////////////////////////////////////////////////////////////////////////////////////////////////////

if (Count >= 300)
{
      NRF_I2S->TXD.PTR = (uint32_t)&pcm_samples[Count - 300];
      NRF_LOG_INFO("Tx - Index:%d, Tx - Vel:0x%08x ", Count, pcm_samples[Count]);
}

Count  ++;

//////////////////////////////////////////////////////////////////////////////////////////////////////

i was do like that to try to play that sound delay

but after few second i can hear only "bzzzzzzzzzzzzzzz" sound 

i don't know what is wrong...

help me to solve this problem 

thanks for read.. 

i will wait reply

Thanks again .

[Kenneth]

What happens when Count wrap around (and start from 0 again, what does TX play then)? 

Kenneth

[Empe]

Thanks for reply.

when i check the log and scope.

during Count < 300 Only Rx Data come to and no Data on Tx Data line.

after 300, Rx Data still come to and some Tx Data going out to data line...

but i can hear only bzzzz sound 

[Kenneth]

Have you tried to play some data from the end of the buffer when Count < 300?

I think maybe the codec in this case may go into some kind of weird/mute state if the output data is 0 for a period of time (which is not something that will occur in a real scenario).

Kenneth

[Empe]

Yes.. i was tried to 

play music front of mic and listen spk's side (checking log to check Count)

before 300 i can not hear anything

but after 300, i can hear "bzzzzz" sound and real-time music 
(it mean's not a part of start point of music)

i dont't know why it happend

save method is wrong or write method is wrong/

[Kenneth]

I do not have a good suggestion here, other than try and fail a bit. You may for instance have several buffers of 300bytes, and try to switch between them to see if anything helps. Maybe you need to increase the gain of the microphone.

Kenneth