I2S , you can't run in full duplex mode.
You can use HFP profile which uses PCM .
Thanks & Regards,
As discussed within the internal case on the topic.
I2S is full duplex in that the input and output pins (2) operate independently of one another.
Full Duplex is not possible on either pin in isolation.
Within WICED, the HFP profile is used by the following 20706 application: /20706-A2_Bluetooth/apps/snip/bt/hci_handsfree
Also, please refer to this thread regarding PCM availability to the application: CYBT 343026 PCM interface TDM control
As this one has evolved quite a bit internally, I wanted to take a minute to update the discussion here so that anyone wondering the same thing in the future has clear direction on the functionality contained within the I2C interface.
First off, we should break these two apart:
- I2S is for high quality audio, so it’s used in profiles like A2DP and is primarily leveraged for music
- PCM is for low quality voice, so used in profiles like HFP for voice calls, etc.
- The hardware I2S/PCM block is unidirectional when configured as I2S at 44.1 and 48kHz sample rate.
- When it is configured as PCM (i.e. for HFP use cases), it’s bidirectional but can only support sample rates of 8kHz and 16kHz.
I spoke to the chip architect this morning and he confirmed that I2S on all our chips is only half-duplex.
Again, sorry for the ambiguity created by this thread on the topic.