“This is not real time oscilloscope! First you acquire signal by saving/logging it to SD card. Then you review the acquired signal on your PC. This oFFline oscilloscope is intended for automotive sensor diagnostic. 99% of automotive sensors work in range from 0v to 5v. Ideal for Arduino. Of course, you can use it wherever you like as long you obey 0v to 5v input range. There are many Arduino oscilloscope modifications. If you by some external hardware + arduino you will get usable real time oscilloscope. If you use only arduino as oscilloscope sampling rate will be very small, almost unusable for anything. After searching the web I found that arduino can fast log of his analog pins to SD card. Combining that with some “Processing 2” code you can have some sort of offline oscilloscope.”