I plan to burn a version of the HT20 arduino code with a start-up freq of 13.555 400.
So to verify I can do it, I compiled the current V2.0 code, 20M, used he correct Etherkit 5351a lib and got a good compile.
Burned a virgin 328P with default fuses via a TinyUSB ICSP. No bootloader.
On power up, the sidetone was very, very slow. It was the right CW just SLOW.
I noticed the Low fuse default is 0x62 which is Clock divide by 8. I changed it to 0xE2
which is NO /8 for clock.
That improved the CW speed and now it is about 1/2 of normal.speed. Still slow though.
The rest of the radio seems ok, it receives fine. Of course the 5351a synth has its own clock and only gets I2C commands from the 328P.
Some on the group have said that no changes are needed to the default fuses but that does not seem to be the case for me.
I burned direct ICSP, no boot loader with avrdude. Not using the bootloader should make no difference.
I tried to read the fuses from the stock micro supplied with the kit but it seems locked so could not read it. That would tell me a lot.
Some fuse settings on Atmel chips can lock out any further ICSP programming. That may be my case.
Does everyone program using the bootloader? Maybe I should try that?