Mar 03, 2016 ยท The CPU is $20 and the display board is less than $10, so this a lot of capability for a fairly low price. The ADAU1701 can be configured in many ways, but the load I'm using is 4 channels with 8 biquads per channel, plus delay for each channel, plus 8 shared biquads for overall EQ. That's a lot of DSP horsepower for such a low price.. The USBi is really easy to reverse engineer -- just use a USB enabled microcontroller and replicate the USBi's descriptors. If you use a tool like USBlyzer to capture the USB traffic, you'll see it's just packetized I2C writes that go straight to the ADAU1701.. "/>Adau1701 dsp board