I recently ordered some PCBs from Elecrow for the Vic's beer-measurement system I've been designing with Rob. While on the site, I noticed that they have a single-channel digital oscilloscope kit based on an STM32. This is a JYE Tech DSO138 which arrives as a PCB whose surface-mount stuff has been fitted, along with a whole bunch of pin-through components for you to solder up the scope yourself. There's a non-trivial number of kinds of components, so first you should prep by splitting them all up and double-checking them all.

Preparing the components

Once you've done that, the instructions start you off fitting a whole bunch of resistors...

Step 1, fitting resistors

Then some diodes, RF chokes, and the 8MHz crystal for the STM32.

Step 2, fitting diodes, a crystal, and chokes

The single most-difficult bit for me to solder was the USB socket. Fine pitch leads, coupled with high-thermal-density socket.

Step 3, the USB socket

There is a veritable mountain of ceramic capacitors to fit...

Step 4, all the ceramic capacitors

And then buttons, inductors, trimming capacitors and much more...

Step 5, buttons, inductors, trimming capacitors, etc

THe switches were the next hardest things to solder, after the USB socket...

Step 6, Switches, connectors, etc

Finally you have to solder a test loop and close some jumpers before you power-test the board.

Step 7, Test loop and jumper soldering

The last bit of soldering is to solder pins to the LCD panel board...

Step 8, LCD panel

Before you finally have a working oscilloscope

Working oscilloscope!

I followed the included instructions to trim the scope using the test point and the trimming capacitors, before having a break to write this up for you all. I'd say that it was a fun day because I enjoyed getting a lot of soldering practice (before I have to solder up the beer'o'meter for the pub) and at the end of it I got a working oscilloscope. For 40 USD, I'd recommend this to anyone who fancies a go.