Android Oscilloscope

Low frequency oscilloscope for Android using Arduino Uno or Nano. The input is to pin A0 of the Arduino which connected to Android device via USB OTG cable.

This scope is for low frequencies, up to 5KHz. The sampling is done by the Arduino ADC in a speed of about 10Kspm. The Arduino software is mostly in Atmel code in purpose to get wider bandwidth. The software for Android is in B4A basic for android.

The Arduino takes 60 samples of input, 60 samples create one screen. For lower frequency a delay of 1mS for each sample gives slower sweep.

To install the app on Android device place the APK file in the device, when you open the file it ask if you want it installed. Upload code to the Arduino and connect it via OTG cable. OTG (On The Go) is the cable that is used to connect USB devices (other than charger or PC) to phones or tablets.

Input is DC or AC not acceding 5V. The 100K resistors set the analogue input to 2.5V and that runs the line in the centre of the screen. Pins 6, 7 are inputs of analogue comparator, it detects rising of signal and starts a frame of sampling.