Hi,
I am trying to figure out how to change the automatic gain settings on the on-board microphone. It is connected via its I2C to the hardware codec, but apparently not to the nrf5340 SoC. How can I access the hardware codec I2C bus to program the registers on the VM3011 microphone?
Hello,
Sorry about the delay here.
The microphones is configured in the hw_codec driver by populating the pdm_mic_enable_configure array with suitable elements and passing the array to cs47l63_comm_reg_conf_write in hw_codec_default_conf_enable when the gateway or headset device is running a configuration of the nRF5340 Audio application which uses the microphone. The links in the previous sentence is to the relevant lines in the application source code in the following files: nrf5340_audio/src/drivers/cs47l63_reg_conf.h and nrf5340_audio/src/modules/hw_codec.c.
You can change the gain by changing the values for CS47L63_IN1L_CONTROL2 and CS47L63_IN1R_CONTROL2 to other valid values. See the relevant excerpt from Table 4-5 from the CS47L63 datasheet here:
Best regards,
Maria
Thank you for the data sheet references and for your patience.
The ZPL mode will activate when there is no clock applied. The relevant register in the CS47L63 to configure this is INPUT1_CONTROL1. 
In the nRF5340 Audio application this is configured in pdm_mic_enable_configure: https://github.com/nrfconnect/sdk-nrf/blob/v2.6.1/applications/nrf5340_audio/src/drivers/cs47l63_reg_conf.h#L66
Best regards,
Maria
Thank you for the data sheet references and for your patience.
The ZPL mode will activate when there is no clock applied. The relevant register in the CS47L63 to configure this is INPUT1_CONTROL1.
In the nRF5340 Audio application this is configured in pdm_mic_enable_configure: https://github.com/nrfconnect/sdk-nrf/blob/v2.6.1/applications/nrf5340_audio/src/drivers/cs47l63_reg_conf.h#L66
Best regards,
Maria
