Arduino audio output circuit

Question

I am looking to build my own arduino-based board that, when triggered, will play a file (line out, not amped to a speaker). Most of the audio shields I see are more complicated than I need, so what I'm wondering is what is the barebones circuit I would need for audio output? I've got the atmega and SDcard side fine, I'm just not sure what IC's are involved in audio output. WAV's are fine so I don't have to deal with mp3 decoding.

PS feel free to move this to electronics instead of arduino, I'm not sure where it belonged since it's built into an arduino board but is more the electronic circuitry.

Answer 1

If you don't care much about quality then all you need is two capacitors and a resistor. Use PWM to create the audio (there is a timerpcm pr something library that will do it). The resistor and pne capacitor form a low pass filter for the PWM, and the other capacitor removes the dc offset.

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• user23244: Kudos for a text-based LPF but why couldn't you upload a picture of the filter in your answer?
• Majenko: Because at the time i didn't have one to hand and the question wasn't worth spending the time making one. Also we didn't have the schematic editor enabled back then.