Hi,
After switching ON printer, it will take some time to become active, in that duration it may give busy state,
so better you check busy also, else wait for 1 sec afer switching ON printer(for time beeing)
and give a delay between each charecter, that will do...
I prtefer using a 5V level signals, i doubt that(3.3V) may be problem.
One more precaution: Send two bytes 1BH,40H, (Esc,@)before sending and data to printer, this is initialization command used on many of the dot matrix printers.
KamalS: We can print graphics also using Esc/P commands. But we cannot assure that it will work for all dot matrix printers.
--Babesh.