I am currently working on controlling dc-dc converter using arduino. I am working with arduino atmega 2560 (fosc=16MHz) but I am facing a problem. The system (dc-dc converter) is very fast and it needs a sampling time of 13 usec (so small) apparently I had to go to the register level to sample every 13 usec this was not available in the built in function. but the arduino takes 8 msec to execute the main loop ..Do you feel the problem?? I need to sample, execute the control code and output a control action in a time less than 13 usec so that I can capture the next sample in the correct timing.