Hi,
On Rock Pi 4B there is dedicated place where microphone could be soldered:
In this forum post it is written that:
For ROCK Pi 4B, the mic is routed to the on board mic by default. For ROCK Pi 4C, the mic is default for headphone jack. You can either solder a mic on the board or change to 4C.
According to it, since I have 4B model, I assume that on-board microphone should be working with no issues.
Here is the schematic for microphone connection(from Rock Pi 4B schematic, page 26)
And below is the schematic from my MP34DT06J model microphone datasheet.
I have soldered following way:
- Mic Vdd(1) -> J1 Vdd (1)
- Mic LR(2) shorted with mic GND(5) -> J1 GND(5)
- Mic CLK(3) -> J1 CLK (3)
- Mic Dout(4) -> J1 SDA(4)
Then I tried to record the file with following command:
arecord filename.wav
Resulting audio doesn’t have any sound. In contrast, I tried the same with USB microphone, and it worked correctly.
Furthermore, in Pulse Audio Volume Meter(recording), there is no change in audio level when I speak to the microphone.
So, I believe microphone is not active.
I checked the clock and data lines, there is nothing on data line, and clock line doesn’t seem to have constant frequency.
My guess is that ES8316 doesn’t behave as a proper master maybe.
Is there anything to be done in Linux configuration to enable microphone?
Also, according to the datasheet my microphone has PDM output. May it be the issue? The mic IC package is a perfect fit for the on-board mic footprint.