Use I2S play sound

[john.liu]

 I use Nrf52832 and sdk16.0.Use I2S play sound.

If use:

int16_t sine_table[]= {0,0,23170,23170,32767,32767,23170,0,0,-23170,-23170,-32768,-32768,-23170,-23170};

NRF_I2S->TXD.PTR=(uint32_t)&sine_table[0];
NRF_I2S->RXTXD.MAXCNT=sizeof(sine_table)/sizeof(uint32_t);
NRF_I2S->TASKS_START=1;

It has sound output.

If use:

const uint8_t output[260760] = {0x13, 0xFC, 0xD9, 0xFA, 0x92, 0xF7, 0x14....};

This output file comes from https://github.com/NordicPlayground/nRF52-teensy-sgtl5000-audio/blob/master/Convert%20Audio%20Sample/car_sample_full.c

  NRF_I2S->TXD.PTR=(uint32_t)&output[0];
  NRF_I2S->RXTXD.MAXCNT=sizeof(output)/sizeof(uint32_t);
  NRF_I2S->TASKS_START=1;

It didn't respond.

Thanks!

i2s.rar

[Turbo J]

Simple explanation:

int16_t sine_table[]= {} will be put into RAM.

const uint8_t output[260760] = {} will be put into FLASH.

EasyDMA does not support reading from FLASH, that is why the second example won't work properly.

[Jørgen Holmefjord]

You need to split up the data in multiple smaller buffers. The buffer pointers in the I2S peripheral is double-buffered, and you will receive events when the buffers are swapped. See Transmitting and receiving and EasyDMA for more details.

If you need to store the data in flash, you can copy it into the RAM buffer when you want to use it.

[john.liu]

Thank you!

Question 1:

I have subcontracted transmit.But But it's all noise.

I setting :

MCKFREQ=I2S_CONFIG_MCKFREQ_MCKFREQ_32MDIV63

RATIO=I2S_CONFIG_RATIO_RATIO_32X

SWIDTH=I2S_CONFIG_SWIDTH_SWIDTH_16BIT

CHANNELS=I2S_CONFIG_CHANNELS_CHANNELS_LEFT

This sound file comes from https://github.com/NordicPlayground/nRF52-teensy-sgtl5000-audio/tree/master/Convert%20Audio%20Sample

Question 2:

I want setting EVENTS_TXPTRUPD interrupt.What should I do?I didn't find the interrupt  interface.

Please help me analyze the source code.thank you.

i2s.rar