doodlezucc
New member
Hi, I'm trying to build a small audio interface using Teensy 4.0 and the accompanying Audio Shield. As a software guy this is pretty new territory so please bear with me.
I've managed to join and solder both parts together and successfully played audio from my PC to the board's output headphone jack. What I actually want to achieve is reversing this connection by feeding an electric guitar signal (or any audio signal for that matter) into the Audio Shield, then using the USB connection to pass it on to my computer.
As noted in this forum thread, it should be possible to simply hook up a guitar to the Audio Shield's line-in. So that's what I tried:
This might be really naive and please correct me if I'm wrong, but connecting GND to the sleeve and line-in L to the tip of an instrument cable is all I need to do to involve my guitar signal in the electrical circuit, right?
Theoretically I should have some audio signal flowing in the left channel of my I2S input at this point. In order to confirm this, I tried multiple Teensy audio examples (PeakMeterStereo, PassThroughStereo) with audioShield.lineInLevel and audioShield.micGain at different values (partly using line-in L, partly MIC), I tried wiring line-in L directly to 3.3V. Nothing yielded any satisfying result, though. There's not even any noise. The peak meter indicates no input on both channels and when passed to my PC and recorded through Audacity it shows a flatline.
Does anyone know what Teensy pins are used for I2S inputs? Maybe my soldering's just a bit unstable at places.
Cheers
I've managed to join and solder both parts together and successfully played audio from my PC to the board's output headphone jack. What I actually want to achieve is reversing this connection by feeding an electric guitar signal (or any audio signal for that matter) into the Audio Shield, then using the USB connection to pass it on to my computer.
As noted in this forum thread, it should be possible to simply hook up a guitar to the Audio Shield's line-in. So that's what I tried:
This might be really naive and please correct me if I'm wrong, but connecting GND to the sleeve and line-in L to the tip of an instrument cable is all I need to do to involve my guitar signal in the electrical circuit, right?
Theoretically I should have some audio signal flowing in the left channel of my I2S input at this point. In order to confirm this, I tried multiple Teensy audio examples (PeakMeterStereo, PassThroughStereo) with audioShield.lineInLevel and audioShield.micGain at different values (partly using line-in L, partly MIC), I tried wiring line-in L directly to 3.3V. Nothing yielded any satisfying result, though. There's not even any noise. The peak meter indicates no input on both channels and when passed to my PC and recorded through Audacity it shows a flatline.
Does anyone know what Teensy pins are used for I2S inputs? Maybe my soldering's just a bit unstable at places.
Cheers
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