A timer ISR should not block serial data reception at all, unless you are doing a ridiculously large amount of stuff in it, which it appears not.
You should not need delays, short or not.
Sorry I can't help more debugging code that I can't see.
A timer ISR should not block serial data reception at all, unless you are doing a ridiculously large amount of stuff in it, which it appears not.
You should not need delays, short or not.
Sorry I can't help more debugging code that I can't see.