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First full test of DDS gen

A project log for Funktion Generator

An AVR DDS function generator.

tim-savageTim Savage 03/02/2017 at 13:280 Comments

Completed revision 1 of DDS output schematic and built up on breadboard/prototype. I might want to improve the power supply with more rails. Currently the power supply is only providing two +-5V rails, might be a better idea to provide a +-5 Volt for output amplifier, a separate 5V for running the AT Mega and possibly a 3.3 if I go down the path of using a ESP8266, otherwise the second 5V rail will suffice for both. Another thing that might be worth investigating is boosting the output rails to 9V to allow +-5V amplitude. Clipping starts to occur at around +-3.5V.

In this setup I'm driving the DDS generator via I2C from the bus pirate. Letting me adjust frequency and wave-forms. Giving a nice output:

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