I discovered this tiny oscilloscope kit the other week. It’s a DSO138 by JYE Tech – £30 from Amazon(UK) or less than £20 if you can wait for delivery from China 🙂
It took me less than 2 hours to build and worked first time! I’ve still got some soldering skills lol. It comes in two versions – one with the SMD components already soldered or one with completely bare PCB.

There’s open-source firmware available that supports data export to PC and it can be made 2-channel with the addition of a little extra hardware. Based on an ARM cortex A3 MCU, it can be re-programmed using Arduino tools.
Great little project for STEM & electronics education.

A couple of days after I’d built the DSO138 I realised there’s a newer/better version on the JYE Tech website – the DSO138mini, and I also came across another project – this one turning a STM32F429 discovery board (which I happened to have lying around 😉 ) into a tiny ‘scope:
(Updated version + link to the original project at https://github.com/deividAlfa/STM32F429-Discovery-Oscilloscope )
A couple of traces I captured with the “export via serial port”. Easy as cat /dev/ttyUSB0 > image.bmp

