I2S programming on nRF52840

RE: I2S programming on nRF52840

MartinBL — Fri, 13 Jul 2018 12:42:42 GMT

Hi,

The code vill return from sd_app_evt_wait() on any interrupt that is being forwarded to your application (BLE, button presses, timers, etc.). Can you post your code?

RE: I2S programming on nRF52840

Rahul Bedarkar — Fri, 06 Jul 2018 10:40:48 GMT

Hi Kenneth,

Thanks for your reply.

I am using sd_app_evt_wait() before writing next buffer. But mp_block_to_fill is NULL in most of cases when sd_app_evt_wait() returns. This means that some other interrupt has come. I have BLE connection active, may be there is some activity going on. How to wait only for I2S transfer complete such cases?

Thanks,

Rahul

RE: I2S programming on nRF52840

Kenneth — Wed, 04 Jul 2018 14:00:54 GMT

Hello,

1. This is just for power optimization, to keep the CPU in idle when there is nothing to do (waiting for an event), you can remove it if you like.

2. The I2S module is double buffered, you can prepare next buffer while current is written, the max size of each buffer is 8192bytes:
http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52840.ps/i2s.html?cp=2_0_0_5_10_6#concept_gq4_jly_vr
http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52840.ps/i2s.html?cp=2_0_0_5_10_9_16#register.RXTXD.MAXCNT

3. The I2S can be used with softdevice yes, but in that case you can call sd_app_evt_wait() instead of __WFE().

Best regards,
Kenneth