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I'm interested in doing some audio work on fpga. At a minimum this requires a decent dac/adc. Can anyone recommend a cheap board that provides this onboard? See

by ioseph 12y ago

I'm interested in doing some audio work on fpga. At a minimum this requires a decent dac/adc. Can anyone recommend a cheap board that provides this onboard? Seems most kits with audio also contain video and got for around $400 AUD

regularfry 12y ago
I'm not going to register just to check out prices, but a quick google landed me at http://www.fpga.biz/product_info.php?products_id=87 http://www.fpga.biz/product_info.php?products_id=87. Doesn't look like it'll be cheap, though - anyone know how much this is? EDIT TO ADD: A Papilio Pro plus an audio wing looks like it comes out at £77.80, ex VAT.
- fhars 12y ago
  If you want it for (hopefully) christmas, there is also the Papilio Duo Kickstarter: https://www.kickstarter.com/projects/13588168/papilio-duo-drag-and-drop-fpga-circuit-lab-for-mak https://www.kickstarter.com/projects/13588168/papilio-duo-dr...
cnvogel 12y ago
Look for "i2s" modules. E.g. there's one for ~20EUR that adds a stereo ADC/DAC (e.g. also usable for the raspberry pi). It has a "i2s" interface which is the canonical way to interface with audio ADCs/DACs. This can easily be connected to any FPGA. http://mbed.org/cookbook/RS-Audio-Codec http://mbed.org/cookbook/RS-Audio-Codec http://en.wikipedia.org/wiki/I%C2%B2S http://en.wikipedia.org/wiki/I%C2%B2S http://blog.koalo.de/2013/05/i2s-support-for-raspberry-pi.html http://blog.koalo.de/2013/05/i2s-support-for-raspberry-pi.ht...
VLM 12y ago
Unfortunately "decent" is vague with dacs and adcs because there's at least 3 figures of merit usually you only get to max out 1 at a time. Assuming your app needs to max out any of them. So if you want 24 bit input with a low noise floor good luck getting above "KHz" sampling ranges yet if you want 500 megasamples/sec you're looking at like 8 bits. Or if you want on board signal processing (differential inputs, maybe a built in multiplier, or 8 input mux on the input so you can read 8 things) you'll "pay" for that one way or another. The good news is this board has a pmod connector and go to digilent and search for pmods and there's some great COTS plug and play A/D and D/A. The bad news is there's... one pmod connector. That really sucks as the amount of fun you can have scales with about the cube or so of the number of peripheral devices connected. If only this "stick" had two pmod connectors. My go-to screwing around board is a mere $90 basys2 and its got 4 pmod connectors and a ton of onboard stuff. So I'm paying an extra $65 to basically not have a headache and have a ton of fun. I can deal with that. If you're willing to not go plug and play just get one of the breadboard to pmod adapter thingies and the RCA breakout and stick like two 8-pin DIP chips on, a D/A and a A/D and call it good. You have to decide if you're trying to minimize spend, or minimize effort (plug and play) and WRT effort are you more into hardware or software. One advantage not discussed about onboard peripherals is they work and are easily tested. There's always a certain distrust, did I blow that chip, can that GD thing actually successfully do I2C at all, etc. Well, if you've got a lot of onboard stuff, just load up the demo / test program if you're feeling worried... Also much as software programmers do a lot with extra added "print" statements for debugging, you'd be surprised what a FPGA dev can do with a bunch of onboard switches and LEDs.

by ioseph 12y ago

regularfry 12y ago

I'm not going to register just to check out prices, but a quick google landed me at http://www.fpga.biz/product_info.php?products_id=87 http://www.fpga.biz/product_info.php?products_id=87. Doesn't look like it'll be cheap, though - anyone know how much this is? EDIT TO ADD: A Papilio Pro plus an audio wing looks like it comes out at £77.80, ex VAT.

fhars 12y ago
If you want it for (hopefully) christmas, there is also the Papilio Duo Kickstarter: https://www.kickstarter.com/projects/13588168/papilio-duo-drag-and-drop-fpga-circuit-lab-for-mak https://www.kickstarter.com/projects/13588168/papilio-duo-dr...

cnvogel 12y ago

Look for "i2s" modules. E.g. there's one for ~20EUR that adds a stereo ADC/DAC (e.g. also usable for the raspberry pi). It has a "i2s" interface which is the canonical way to interface with audio ADCs/DACs. This can easily be connected to any FPGA. http://mbed.org/cookbook/RS-Audio-Codec http://mbed.org/cookbook/RS-Audio-Codec http://en.wikipedia.org/wiki/I%C2%B2S http://en.wikipedia.org/wiki/I%C2%B2S http://blog.koalo.de/2013/05/i2s-support-for-raspberry-pi.html http://blog.koalo.de/2013/05/i2s-support-for-raspberry-pi.ht...

VLM 12y ago

Unfortunately "decent" is vague with dacs and adcs because there's at least 3 figures of merit usually you only get to max out 1 at a time. Assuming your app needs to max out any of them. So if you want 24 bit input with a low noise floor good luck getting above "KHz" sampling ranges yet if you want 500 megasamples/sec you're looking at like 8 bits. Or if you want on board signal processing (differential inputs, maybe a built in multiplier, or 8 input mux on the input so you can read 8 things) you'll "pay" for that one way or another. The good news is this board has a pmod connector and go to digilent and search for pmods and there's some great COTS plug and play A/D and D/A. The bad news is there's... one pmod connector. That really sucks as the amount of fun you can have scales with about the cube or so of the number of peripheral devices connected. If only this "stick" had two pmod connectors. My go-to screwing around board is a mere $90 basys2 and its got 4 pmod connectors and a ton of onboard stuff. So I'm paying an extra $65 to basically not have a headache and have a ton of fun. I can deal with that. If you're willing to not go plug and play just get one of the breadboard to pmod adapter thingies and the RCA breakout and stick like two 8-pin DIP chips on, a D/A and a A/D and call it good. You have to decide if you're trying to minimize spend, or minimize effort (plug and play) and WRT effort are you more into hardware or software. One advantage not discussed about onboard peripherals is they work and are easily tested. There's always a certain distrust, did I blow that chip, can that GD thing actually successfully do I2C at all, etc. Well, if you've got a lot of onboard stuff, just load up the demo / test program if you're feeling worried... Also much as software programmers do a lot with extra added "print" statements for debugging, you'd be surprised what a FPGA dev can do with a bunch of onboard switches and LEDs.