I am using an Arduino Pro Mini for this quantizer I am building, and it works fantastically when I power it via a USB cable from my computer, but when I started powering the controller via a +/-12v power supply everything stops working. Basically I am testing my circuit by quantizing an LFO signal (Vin) and then outputting the quantized voltage to an oscillator. It is working as expected when the Arduino is powered via USB, but once I start powering it by +12V the quantized voltage out (Vout) is no longer quantized - it is just a constant rising and falling voltage (much like the LFO at Vin).I am powering the Arduino with +12v via the RAW pin - which allows 5v - 12v input and converts it down to 5V. Everything else in the circuit gets powered by 5V. I have also attempted powering the Arduino using an LM7805 voltage regulator (as seen in my schematic) but I still get the same results. One thing I particularly suspect is the MCP4725 DAC I am using. Any recommendations or ideas of what is going on? Its obviously something to do with power... possibly a current issue?
I didn't find the right solution from the Internet.
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