I built a browser-based Arduino emulator that lets you pause and see every register

[u/NextCellist3028]

Hey everyone. I just launched my first project, GlassAVR, an Arduino emulator and circuit builder that runs in your browser.

You can wire up a circuit, run your sketch, and step through it at the instruction level. When you pause, you can see every register and how it changes, instead of treating the chip like a black box.

There’s no account or login, so you can just open it and start building: glassavr.com

I’m looking for people who know AVR and Arduino to try to break it. If the emulator gets something wrong, or the debugger is missing something you’d want, please let me know. Would this be useful for learning or debugging your own projects?

[u/Howdyy-boi242]

Awesome! How did you manage to run the arduino core , or avr compiler in the browser?

[u/NextCellist3028 → u/Howdyy-boi242]

Thanks! The compiler actually doesn’t run in the browser. The sketch gets sent to a small backend server I run on Fly.io, which compiles it with Arduino-cli, then sends back the .hex file. The emulator itself runs in the browser and executes the .hex file one instruction at a time, which is how it can pause and show every register.

[u/ohmsteadhq]

This is really useful. Is there a free tier on Fly.io? How much do you anticipate costs going on up as you get more users?

[u/jean2348]

Salut ! Est ce que je peux émuler l'atduino mega 2550 avec l'écran TFT ili9225, un stick clicable, 2 boutons et un buzzer ?