1. Install the Android App
Install the Scoppy Android app from the Play Store.
2. Download the Firmware
Different firmware is available for the Pico and Pico W. The Pico firmware is not compatible with the Pico W and vice versa. Download the firmware by selecting one of the following links.
For the FHDM DSO-500K see here.
Older firmware versions can found here.
3. Install the Firmware
Push and hold the BOOTSEL button on the Pico, then connect it to your computer using a normal USB cable (Type-A male to Micro-USB male). Your computer should detect the Pico as a USB Mass Storage device. Release BOOTSEL once the drive RPI-RP2 appears on your computer. Copy the uf2 file to your Pico.
The onboard LED should start blinking.
4. Connect the Pico or Pico W to your Phone/Tablet
Communication between the firmware on the Pico (or Pico W) and app on the phone/tablet can be either via USB or Wi-Fi (Pico W only).
Attach the small end of the OTG cable/adapter to the USB input of the Android device (do NOT plug it into the USB socket of the Pico!). Then use a USB cable to connect the OTG cable/adapter to the Pico (or Pico W). You should see the status LED on the Pico start blinking.
Once you open the app and a connection is established between the Pico and the Scoppy app the onboard LED should stop blinking. You may need to tap the ‘Run’ button in the app if the scope is currently stopped (Scoppy will either be RUNNING or STOPPED. This status is displayed at the top right of the grid).
Please note that if you are using a Pico W and a connection over USB hasn’t been established within 10 seconds the Pico W will start listening to connections over Wi-Fi. To try connecting via USB again the Pico W will need to be restarted.
b. Wi-Fi (Pico W)
Please see Getting started with Scoppy and the Pico W. Once connected, continue to Step 5 below.
5. Connect a signal source
Attach the +ve output of your signal source to GPIO26 of the Pico and the ground to gnd. This will allow you to measure signals between 0V and 3.3V. Of course the signal voltage should be within the allowed range of the ADC pins of the RP2040. See section 5.2.3 of the RP2040 Datasheet for more information. For Channel 2, connect the signal to GPIO27.
You might want to insert a current limiting resistor (eg 100R) between the signal source and the pico ADC (GPIO26/27) to limit the current through the Pico ESD diodes in case you accidentally apply a voltage higher than 3.3V.
If you don’t have a suitable signal source you can view the test signal on GPIO 22 by connecting it directly to the ADC pins (GPIO 26 and 27). GPIO 22 is a 1kHz square wave with a duty cycle of 50%.
To measure signals outside of the 0 to 3.3V range of the Pico ADCs you will need some form of circuitry between your signal source and the Pico ADC. See the Analog Front-End documentation for more information.
Test signal connected to GPIO 26. Horizontal time/div needs adjusting :)
Logic Analyzer Mode
To use Scoppy as a logic analyzer tap the Menu button and then the Mode button and tap ‘Logic Analyzer’. The logic analyzer inputs are GPIOs 6 to 13. Please remember to only apply voltages of between 0 and 3.3V to these pins.