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Raspberry tests
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Open effebal opened 8 years ago

effebal commented 8 years ago

Hi Michel,

great work on this adc. Could you please help me to understand how to use as a soundcard. I was able to compile and load the module, but how can I use with alsa? The sound card is not listed in the alsa ones (using the arecord -L command).

Thanks and regards

mpromonet commented 8 years ago

Hi effebal, I did not work on this since a while, my aim was to use an adc with xoscope and make some tries with kernel programming. If I remember well, it works a little with a PCF8591 using the /dev/dsp interface.

In order to create the card, you need not only to load the snd-pcf8591 module. It is needed to create the I2C device indicating the I2C address, something like :

 echo "pcf8591 0x48" | sudo tee /sys/bus/i2c/devices/i2c-0/new_device

This should trig the probe, and it should have some log in dmesg about snd_card_register. Anyway an adc is probably quite bad for capturing audio, it will miss samples, capture period will vary a lot. Regards, Michel.

effebal commented 8 years ago

Hi Michel,

many thanks for your help. My needs regards the possibility to use a spi adc with some driver like your spi-mcp3002, so my question. The idea is to have something similar to alsa in order to use like a soundcard.

But I agree with your sentence regarding the bad audio capturing.

Thanks a lot,

Francesco

2016-03-05 13:02 GMT+01:00 Michel Promonet notifications@github.com:

Hi effebal, I did not work on this since a while, my aim was to use an adc with xoscope and make some tries with kernel programming. If I remember well, it works a little with a PCF8591 using the /dev/dsp interface.

In order to create the card, you need not only to load the snd-pcf8591 module. It is needed to create the I2C device indicating the I2C address, something like :

echo "pcf8591 0x48" | sudo tee /sys/bus/i2c/devices/i2c-0/new_device

This should trig the probe, and it should have some log in dmesg about snd_card_register. Anyway an adc is probably quite bad for capturing audio, it will miss samples, capture period will vary a lot.

Probably Regards, Michel.

— Reply to this email directly or view it on GitHub https://github.com/mpromonet/rpi/issues/1#issuecomment-192626942.