EasyTransferI2C with 3 Arduinos - trouble w/ Master Tx & Rx

Thanks Pylon. But, I'm still stuck... I'm having trouble understanding your feedback, with regard to how to implement this via EasyTransferI2C. I had assumed that some of this is handled by the library. Are the "wire.onRequest" and "wire.onReceive" needed? Do I use the ".sendData()" in stead of the ".write()"?

Further troubling was that this combination would not compile

Wire.onRequest(requestEvent);           // register event
void requestEvent(int numBytes) { }

with the following error:

:136: error: invalid conversion from 'void ()(int)' to 'void ()()':136: error: initializing argument 1 of 'void TwoWire::onRequest(void (*)())'

I've trimmed out the multiple structures and simplified things a bit.

New files are here:Dropbox - Bedini_AutoTuner - Simplify your life

...Not sure exactly where to go from here. Any thoughts?