Oscilloscopes are expensive and largely reserved for makers or electronics engineers O who need to understand what a circuit is doing. We can’t make our own, simple oscilloscope and logic analyser with a £4 Raspberry Pi Pico, right? It turns out that with a Raspberry Pi Pico, some software called Scoppy and an old Android phone, we can do just that.
For the low, low price, we can’t expect the earth. This won’t rival an expensive setup, but for most of us, it is enough to understand and get to grips with the equipment before we open up our wallet.
In this tutorial, we learn how to configure a Raspberry Pi Pico as an oscilloscope and use the Scoppy Android app to read live data from a circuit. Note that due to the Raspberry Pi Pico’s 3.3V logic, we cannot measure voltages any higher, otherwise we risk damaging the Raspberry Pi Pico’s ADC pins.
Setting up Scoppy
While holding the BOOTSEL button, connect your Raspberry Pi Pico to your computer. Go to https://oscilloscope.fhdm.xyz/wiki/Installation-&-Getting-Started and download the Scoppy firmware for your Pico or Pico W. Open your file manager, go to the downloaded file and copy it to the root of the RPI-RP2 drive. This flashes the new firmware to the Pico. When done, remove the Pico from your computer and connect to your Android device. Depending on your phone, you need an adaptor to connect. The Raspberry Pi Pico uses a micro USB port, but our old phone uses USB type C. We’re using a micro-USB-male-to-USB-A lead, so a USB-A-to-USB-C adaptor is a cheap and easy way to connect the USB A side of the lead to the USB C port of the phone.
We now need to install Scoppy on our Android device. Open the Google Play Store on your device and search for Scoppy -Oscilloscope. Alternatively, you can open the store in your desktop web browser and manage the installation remotely by going to https://play.google.com/store/apps/details?id=xyz. fhdm.scoppy.
Open the Scoppy application and you are prompted to allow Scoppy to access Pico. This is the default name given to the Raspberry Pi Pico by the Scoppy firmware. Allow access and we are dropped into the Scoppy oscilloscope user interface. Initially this is quite an overwhelming experience.