Hello,
I'm trying to build a Computer DMX Interface so I used the Arduino IDE to program another external ATMega328P. Everything works fine at 1MHz Clock speed (except that the internal clock is too unacurate to send all DMX channels properly), but when go up to 8 MHz internal, SoftwareSerial is only connectable with baud 2400 instead of 19200 (as it would think clock is still 1MHz, although F_CPU seems to be ok) and DMXSerial is same as with 1 MHz. With 16 MHz Quarz DMXSerial canceles its Service completly and the baudrate sinks down to 1200... I don't knwo what the Problem is, but their must be another solution than using an 8MHz Quarz and CLKDIV8...
LG veecue