Well so far so good ( at least sending to the device) with just the little 12F675. I put the bit/byte patterns into eeprom and read them into bitstream output for each requested command to the device.
I built a control switch pad this weekend using A/D on one pin.
My next step is to include an encoded POT output device to control a second piece of equipment at the same time. I have two pins left..... oh boy !!

These chips is fun!!