4 * Olimex AT Mega32U4 "T" board
5 https://www.olimex.com/Products/Duino/AVR/AVR-T32U4/
7 For "high speed" operation, the T32U4 must be jumpered to run on 5V!
11 * avr-gcc & companions
14 http://www.fourwalledcubicle.com/LUFA.php
15 in particular, the ClassDriver/AudioOutput demo
16 LUFA-140302/Demos/Device/ClassDriver/AudioOutput/
33 Left channel on OC3A (pin32) -> Olimex "D5" -> probe 4.
35 Run "aplay -D front:CARD=Demo,DEV=0 /usr/share/sounds/alsa/test.wav"
36 while the Saleae records for 8 seconds. The result is pwmtest.sr.
37 Probe 5 was unterminated, see the crosstalk.
39 You can test the PWM decoder via CLI and extract the raw values:
40 sigrok-cli -i pwmtest.sr -P pwm:pwm=4 -B pwm=raw > PWM.raw
42 Add e.g. some .wav header using sox:
43 sox -t raw -e unsigned -b 8 -r 64000 PWM.raw PWM.wav