Attiny2313: listen and repeat

It took about two hours, three evenings and twenty re-programmings to get it working. Though, it probably worked even the first time, since the problem was not in the code.

Once I had verified the 4x4 keypad was read correctly and mapped the Getkbd codes, my target was to send the FT817 a "VFO Toggle" command.

With one Printbin combination I could only get the radio to tune 10'101,01 kHz, while it was supposed to change VFO.

As a last resort I reduced the communication speed from 9600 to 4800 baud (on both the chip and the radio!) and it magically started working. I could also program a static VFO retune command. Cool.

Since the code was not changed I can only assume the internal clock is either not suitable for (fast) serial communications or it is way off the declared/programmed value.