personal_site/_posts/2025-07-20-micropython-simulator.md

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MicroPython Simulator	post	Embedded Programming is fun again!	/assets/blog/micropython/simulated_display.png	/assets/blog/micropython/simulated_display.png	/assets/blog/micropython	A simulator for my USB C Power supply project using Micropython running in websassembly.	<script src="/assets/blog/micropython/micropython.min.mjs" type="module"></script>

This simulator lets me quickly try out micropython code drawing to a 240x240 pixel color lcd display. *

This particular display uses 5, 6 and 5 bits for each channel, respectively. The raw pixel data gets passed from micropython to javascript where it gets converted to normal RGB before being blitted to the <canvas> tag. Under the hood it uses the fact that the micropython VM supports being compiled to WASM.

I'm using a ttf font called gunship converted to bitmap format and frozen into the firmware along with other library code.

Building the code looks like:

cd /ports/webassembly
make min FROZEN_MANIFEST=/path/to/custom/manifest.py
cp ...wasm and ....min.mjs to your webserver directory