The microphone has no sound
When I use the probability of the microphone will not sound, why is it so?
Allan,
Thank you for providing a schematic.
Would you also provide what type of microphone you are using? Some high impedance headsets may have issues with the detection sequence. See this posting for more information
We also need to make sure the detection sequence is being triggered by a high to low transition on the DET_TRIGGER pin.
In the schematic above the there is no way to have the DET_TRIGGER pin pulled low to initiate the detection sequence like the example below.
Here is another post with more detail on how to trigger the detection sequence without using I2C commands.
If there is a mic detected the MIC_PRESENT pin will pull low. Are you able to probe that node?
Let us know if this helps your debug process.
Thank you,
Adam
Ian,
This issue is similar to the one posted early in the thread about detection with high impedance headsets. As you can see in the posting, the TS3A227E internal ADC has a limited number of bits to detect the impedance of ring 2 and sleeve. The max value the TS3A227E can differentiate is 2800 ohms. Since the headsets above have sleeve and ring2 >2800 the TS3A227E is interpreting them to have the same impedance. When the device interprets the same impedance on ring 2 and sleeve it will automatically configure the internal switches to connect ring 2 and sleeve to ground effectively grounding your mic line.
You can change the internal switches using I2C commands to support high impedance headsets.
Thank you,
Adam
Allan,
Every time the power is cycled the TS3A227E register map will reset to the values below. The best way to use this IC without I2C is to have a GPIO used to initiate the detection sequence or use an audio jack that has a mechanical switch.
Thank you,
Adam
