The are a few arduino Oscilloscope projects but they only have a sample rate of 10k. I found this article by Glen Sweeny using the ADC interrupts by using 8 bits and a higher adc clock I should be able to run at higher speeds. Collecting a set of results and then sending them out serially would improve the speed. FirstlyI copied the program and got a compiler error. I removed sections of code and it turned out the compiler din’t like the global variables in the interrupt service routine.