zivilyn861, did you ever get your code working? I’m just getting started on a project using a Video Experimenter to provide an Uno with the synchronization needed to generate LED blinks to calibrate and/or test a low-light video camera. For starters, I’ll be satisfied starting the LED blink during the vertical blanking interval (VBI), though eventually I’ll want to time it more exactly within a frame or field. I’m getting up to speed on the necessary code, and came across this discussion. I’d appreciate learning how your project worked out