No sound output, RCA input issue

[countach]

I recently purchased the version of the audio injector without the built-in microphone. I have a raspberry pi 3 model b. I am booting from USB. I followed the setup and test tutorial.

When I run the audioInjector-test.sh script I can hear a tone through my headphones, however when I play .wav files with aplay I hear nothing and additionally whenever chromium tries to play a sound it crashes the tab. Does the audio injector only support audio that it takes in itself or should it also be able to play system sounds such as a youtube video? If it should play system sounds too, I would appreciate your assistance in fixing that issue.

My second problem is the following. I have a single RCA male adapter that breaks out to two wires (https://www.amazon.com/Speaker-Terminat ... 003U44L9O/) in order to connect to an electret microphone with preamp (https://www.sparkfun.com/products/12758). I have hooked up the leads to a function generator at 1 Volt peak to peak and 1 kHz sine wave and then hooked up the RCA male to the left channel RCA female in on the audio injector. I have turned the volume knob all the way clockwise. I try recording the signal with the arecord command provided in the audioInjector-test.sh script, but again I hear no sound when I use aplay to play back the .wav file that arecord generates. I would appreciate your assistance in troubleshooting this as well.

Overall I am trying to get the analog input from this mic into the pi for use by pocketsphinx.

[flatmax]

Hi there,

The audio injector sound card should be able to play all system sounds. Not sure how your desktop is setup. Can you right click on the volume icon and make sure the correct card is selected ?

Regarding the microphone. You can plug an electret microphone directly into the empty footprint marked "Cmic1" on the board. As long as the polarity is correct, then it should work. I think it would be very difficult to get it working when plugged into the RCA connector. You see, the "mic" footprint is already setup with the correct voltage and decoupling circuitry for an electret microphone. The positive pin should be the pin inside the non white part of the footprint silkscreen painting.

thanks
Matt

[countach]

Ok, so I can now hear arbitrary wav files, but chrome still crashes. I just had to plug my headphones all the way into the jack which requires a little bit of force.

I will try with the electret hooked directly into the board as per your suggestion.

Additionally, I have encountered another problem. My sound is very crackly now that I can hear it. I have heard others suggest getting a better power supply for my pi. The power supply I am using is a 5V 1.8A cell phone charger. Would this charger be sufficient to power both the pi and soundcard?

[countach]

Ok, so I was able to wire my electret microphone up to the pi and record it with arecord which is great. I also have tested my pi/soundcard with a new 5V, 2.5A power supply, however the output sound is still terribly noisy and crackly and the pitch changes.

[flatmax]

The system shouldn't be drawing too much power, for example, a usb cable into a computer should work - which is a maximum of 0.5 Amps of current, however it doesn't draw that much.

Not sure why your sound is crackly and also why the pitch is changing, this is not normal behaviour. ... hmmm. Has chromium stopped crashing ?

Matt