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Project Notes

#268 ChainBlocks

Testing some “Chain Blocks” and demonstrate an XY Plotter block (with an MCP42010 digital potentiometer) by drawing the PrexLab logo on an Oscilloscope.



My neighbour is developing a prototyping system called Chain Blocks by PrexLab, and passed me some to try out. Disclaimer: at no charge.

Chain Blocks?

Chain Blocks sit somewhere on the continuum of ideas that are trying to make electronics more approachable especially for novices:

  • the “building block” approach, perhaps exemplified by littlebits. These require no electronics or coding backgound.
  • the standard Shield/Cape/Hat approach and a miscellany or modules that can be directly wired to the microcontroller development board. These are moderately approachable by beginners but require some electronics to be learned along the way, and you must be ready to code
  • kit-assisted breadboard prototyping, like
  • and beyond that we get into standard protoboard/breadboarding techniques for those willing to dive head-first into electronics as a hobby

I started with a “Chain Nano block with one application block”. I turned the application block into an “XY Plotter Block”.


The XY Plotter Block

For a test, I decided to make an XY plotter block, based on the LEAP#265 XYplotter project.

It uses an MCP42010 dual digital potentiometer to draw images on an oscilloscope.



Test Sketch

ChainBlocks.ino is a test sketch that draws “PrexLab” on a scope.

The Python script is used to interpolate plotting points over the fundamental text structure. It generates the data.h used by the ChainBlocks.ino sketch:

python > data.h

The sketch produces the image below. I’m using a Hantek MSO5074FG oscilloscope, and the image was captured with the following settings:

  • XY plot mode
  • 0.2s persistence
  • display as vectors
  • average over 4 samples
  • CH1/X and CH2/Y offset to position the image


The time-domain plot for the generated output is like this:






Credits and References

Project Source on GitHub Project Gallery Return to the LEAP Catalog

This page is a web-friendly rendering of my project notes shared in the LEAP GitHub repository.

LEAP is just my personal collection of projects. Two main themes have emerged in recent years, sometimes combined:

  • electronics - usually involving an Arduino or other microprocessor in one way or another. Some are full-blown projects, while many are trivial breadboard experiments, intended to learn and explore something interesting
  • scale modelling - I caught the bug after deciding to build a Harrier during covid to demonstrate an electronic jet engine simulation. Let the fun begin..
To be honest, I haven't quite figured out if these two interests belong in the same GitHub repo or not. But for now - they are all here!

Projects are often inspired by things found wild on the net, or ideas from the many great electronics and scale modelling podcasts and YouTube channels. Feel free to borrow liberally, and if you spot any issues do let me know (or send a PR!). See the individual projects for credits where due.