A short update on the remote control project.
A preliminary version of the circuit layout is working on breadboard. It includes an ATmega168, a PCF8574A TWI I/O expander, matrix keypad and LCD display.
I have been able to read the keypad using interrupts and display keypress on the LCD. I have been able, with another piece of firmware, to read data from the FT817 and display it on the LCD.
Now it is "just" matter of putting both codes together and working on a firmware logic that combines a continuous frequency display, keypad input and a sort-of menu driven function selection.