“A 500kS/s oscilloscope built on stripboard using basic parts
In the previous guide we described how to create a simple oscilloscope on a breadboard using a Raspberry Pi Pico W (or Pico) and the Scoppy Android app.
Here we will describe how to extend the input voltage range, increase the input impedance and add some over-voltage protection. This project will be built on stripboard and again uses very basic and easily obtainable components.
The maximum input voltage range of this oscilloscope is ±16V. There is also a ±3.5V range for measuring lower voltages.”