Project Help: troubleshooting DAC/AMP & audio output

Projects General Guidance
1

Hey gang-

I have a project I am working on.. its a mini-arduino based board.. that has on-board microSD socket.. and DAC/BUFFER/AMP for audio output.. (playing .wav files off SD card)

it was based off the WaveShield by Adafruit.. and use the WaveHC lib by default..

using same DAC.. an LM386 amp.....etc

got all pcb's ordered, stencil ordered, all components arrived...etc

assembled my first board.. and re-flowed in my toaster oven..

things worked GREAT!.. no re-flow fixes... no bridges (that I can see)..etc

took optiloader bootloader on first try.. and I loaded up a couple example sketches (blink) and they all loaded & worked fine..

I load the WaveHC lib.. to play the default (all .wav files from SD card in loop)... and it 'looks' as if its playing.

I see this when I view the serial monitor:

Wave test!
Free RAM: 688
Using partition 1, type is FAT16
Files found (* = fragmented):
0.WAV
1.WAV
2.WAV
3.WAV
4.WAV
5.WAV
6.WAV
7.WAV
8.WAV
9.WAV
P.WAV

Playing 0.WAV
.......
Playing 1.WAV
......
Playing 2.WAV
......
Playing 3.WAV
.......
Playing 4.WAV

** I am also powering the board externally to power the DAC correctly.. (in case anyone brings it up as a point of failure) :wink:

** I have tried 3 different, 1watt 8Ohm hobby speakers.. (intended use for this board was always this type of speaker)

looking for some help/sample code to directly send some data to the dac

any ideas?

thanks

2

Did you test the audio amp alone?

3

how can I do that?

Test it how? :slight_smile:

thanks

4

Insert some audio signal on pin 8 of the DAC.

5

thanks!.. but thats a bit over my head with that description. :fearful: :blush:

not sure how I go about doing that...

a different demo sketch??

6

Use an mp3 player (or even your PC's audio out). Solder an audio connector between DAC's pin 8 and ground. Connect the mp3 player and the audio connector with a cable with jacks on both ends. Start with the player's volume low.