Currently, I am working on nRF5340 Audio DK boards. I am using two nRF5340 Audio DK boards to function as a walkie-talkie using the onboard microphones. Using the nRF5340 Audio DK Audio example code, I was able to successfully implement the walkie-talkie functionality.
Now, I am trying to replace the onboard microphone with an IMP34DT05 microphone on one of the nRF5340 Audio DK boards to achieve the same functionality. I tried using the P15 header, which is connected to the CS47L63 codec, as identified from the schematic.
The onboard microphone uses PDM1, so for the external microphone (IMP34DT05), I used PDM2. I also enabled MICBIAS1C using the configuration { CS47L63_MICBIAS_CTRL5, 0x00000722 }, and I am able to get voltage at the P15 header. This configuration sets MICB1C_SRC = 1 (VDD_A enabled). I would like to confirm whether this is correctly enabled.
While doing this, I am facing issues with the onboard setup. I am unable to hear any audio from the headset.
At this point, I suspect that the issue may be related to clock synchronization or power supply.
I need support with nRF configuration and hardware interfacing for the IMP34DT05 digital microphone with the nRF5340 Audio DK.
Specifically, I am looking for:
- Hardware connections
- Proper pin mapping for the digital microphone (PDM interface)
- Clock (CLK) and Data (DOUT) connections
- Power supply and grounding requirements
- nRF Configuration
- Required changes in PDM configuration in firmware
- Device tree / pin configuration updates (if applicable)
- Sampling rate and gain configuration
- Firmware / Application Support
- I have modified the walkie-talkie example to use an external microphone instead of the onboard mic
- Need guidance to validate whether my changes are correct
- Facing issues with proper audio capture / functionality
Any guidance, reference design, or working example for integrating an external PDM microphone with the nRF5340 Audio DK would be very helpful.imp34dt05.pdf
