RT1010 sai demo audio from jack microphone (WM8960 configuration?)

[marcomerlin]

Hi all,

I am trying to redirect the audio input of the "sai" example from the on-board microphone to the microphone input on the audio jack.

I have been experimenting a lot, but it seems there is no sginal at all coming in.

Here is my codec configuration modified to do so.

Has anybody tried the same and got it working ?

Thank you in advance for your support.

Regards,

MM

/*******************************************************************************
 * Variables
 ******************************************************************************/
wm8960_config_t wm8960Config = {
    .i2cConfig = {.codecI2CInstance = BOARD_CODEC_I2C_INSTANCE, .codecI2CSourceClock = BOARD_CODEC_I2C_CLOCK_FREQ},
#if(1)
    .route     = kWM8960_RoutePlaybackandRecord,
#else
    .route     = kWM8960_RouteBypass,
#endif
#if(0)
    .rightInputSource = kWM8960_InputDifferentialMicInput2, // on board micro -> right
#elif(0)
    .leftInputSource  = kWM8960_InputDifferentialMicInput3, // jack micro -> right
#elif(1)
    .leftInputSource  = kWM8960_InputDifferentialMicInput3, // jack micro -> right
    .rightInputSource = kWM8960_InputDifferentialMicInput2, // on board micro -> left
#else
    .leftInputSource  = kWM8960_InputLineINPUT3, // jack micro -> right
    .rightInputSource = kWM8960_InputDifferentialMicInput2, // on board micro -> left
#endif

#if(1)
    .playSource       = kWM8960_PlaySourceDAC,
#else
    .playSource       = kWM8960_PlaySourceInput,
#endif
    .slaveAddress     = WM8960_I2C_ADDR,
    .bus              = kWM8960_BusI2S,
    .format = {.mclk_HZ = 6144000U, .sampleRate = kWM8960_AudioSampleRate16KHz, .bitWidth = kWM8960_AudioBitWidth16bit},
    .master_slave = false,
};

[alex_rodriguez]

Hi Marco,

Looking at the schematic, your configuration looks correct with:

leftInputSource  = kWM8960_InputDifferentialMicInput3

rightInputSource = kWM8960_InputDifferentialMicInput2

One thing to note is that you should use an OMTP standard headphone with the EVK. Can you try using different headphones and see if that fixes your issue?

Best,

Alex

[marcomerlin]

After a discussion on a Hackster project ( speakEZ - Hackster.io ) I realized the connections to the line-in jack are probably wrong: the microphone is usually the sleeve and GND is the 3-rd pole of the jack. It seems therefore that those two connections got inverted. As a consequence the MIC input is actually grounded, which also explains why my attempts at injecting signal directly from the input jack to the capacitors have failed.

I will give a new look to the board layout, and maybe I will figure out if I can hack it to make it work.

[marcomerlin]

Thank you for the quick reply!

I have already tried a couple of headphones, and with one I had a feeling i was hearing some subtle noise when blowing on the microphone... but it was really difficult to tell.

Actually I would like to inject signal from a different source with an adapter like this one

https://www.amazon.fr/dadaptateur-adaptateur-deffets-guitare-iPhone/dp/B07B28NVG6/ref=asc_df_B07B28N... 

I have tried 2 and with a really strong signal I still could not hear anything on the output.

At some point the signal I was injecting was so strong that the amplifier was getting some output even with the audio demo off.

I have even tried to inject the signal directly on the AC decoupling capacitors on the board (C112 C115), but still nothing.

I could solder some wires on C111 and C114 (on-board microphone input), but it seems a shame to start poking around my brand new EVK when it is supposed to work.

Any advice would be helpful.

Regards,

MM