[HN Gopher] Velxio 2.0 - Emulate Arduino, ESP32, and Raspberry P...
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       Velxio 2.0 - Emulate Arduino, ESP32, and Raspberry Pi 3 in the
       Browser
        
       Author : dmcrespo
       Score  : 44 points
       Date   : 2026-03-27 20:44 UTC (2 hours ago)
        
 (HTM) web link (github.com)
 (TXT) w3m dump (github.com)
        
       | dmcrespo wrote:
       | Hey HN, I posted Velxio here a while back and got great feedback.
       | Since then I've shipped a major update
       | 
       | What's new in v2:
       | 
       | - 19 boards across 5 CPU architectures (AVR8, Xtensa, RISC-V, ARM
       | Cortex-M0+, ARM Cortex-A53) - ESP32 emulation via QEMU (lcgamboa
       | fork) -- real flash images, ROM function emulation,
       | GPIO/ADC/timers - ESP32-C3 and CH32V003 run on a custom RISC-V
       | core written in TypeScript, entirely in the browser - Raspberry
       | Pi 3B via QEMU raspi3b -- boots real Pi OS, runs Python -
       | Realistic sensor simulation: DHT22 (40-bit protocol timing), HC-
       | SR04 (trigger/echo), WS2812B NeoPixel (GRB decoding) - 48+
       | electronic components from wokwi-elements
       | 
       | Architecture:
       | 
       | - AVR, RP2040, and RISC-V emulation runs client-side (avr8js,
       | rp2040js, custom TS core) - ESP32 Xtensa and Pi 3 run on backend
       | QEMU - Compilation via real arduino-cli - React + Vite frontend,
       | FastAPI backend - Self-hostable via Docker, no account needed
       | 
       | Source: https://github.com/davidmonterocrespo24/velxio (AGPLv3)
       | 
       | Happy to discuss the emulation architecture -- particularly the
       | trade-offs between in-browser vs. backend QEMU emulation
        
       | dmonterocrespo wrote:
       | Velxio 2.0 is live.
       | 
       | A free, open-source emulator for 19 embedded boards: Arduino,
       | ESP32, Raspberry Pi, RISC-V , running real compiled code in your
       | browser.
       | 
       | The best part: it's fully local.
       | 
       | No cloud dependency. No student accounts. No data leaving your
       | network. Self-hostable with a single Docker container.
       | 
       | Universities and bootcamps can deploy it on their own servers and
       | give every student access to a complete embedded development
       | environment, for free.
       | 
       | I've been working on this for over a year, and just shipped v2.0
       | with ESP32 emulation (via QEMU), a custom RISC-V core, and
       | Raspberry Pi 3 support that runs real Python
        
         | exe34 wrote:
         | Is it easy to feed an elf or bin and run that (esp32c3)? I see
         | compilation available, but I'm playing with asm and have my
         | toolchain figured out already and would just like to emulate
         | the firmware.
        
         | mech422 wrote:
         | just curious - if it runs from a docker container, what is the
         | advantage of running the browser as opposed to just ssh'ing in
         | ?
        
           | dmcrespo wrote:
           | The main advantage is accessibility and ease of use: with the
           | browser, no setup is required on the user's side, no
           | toolchains need to be installed, and there's no need to be
           | familiar with SSH or terminal workflows
           | 
           | It also provides a more visual and interactive environment
           | (editor, peripherals, simulation controls), which is
           | especially useful for teaching and for beginners.
           | 
           | The Docker image is there so you can easily install it on
           | your own machine if you want to run it locally or work on
           | development
        
       | hex4def6 wrote:
       | First of all: Awesome work! Playing with it now.
       | 
       | One suggestion: The main splash screen image is nearly 8MB big.
       | It takes a noticeable time to download on my connection. I'm not
       | sure what bandwidth costs these days, but seems like that could
       | be something to optimize.
        
         | dmcrespo wrote:
         | Thanks a lot! Yes, that's something I have pending, I'm
         | planning to replace it with an SVG or an animated GIF to
         | improve loading time
        
       | radicality wrote:
       | I often write a bunch of Esphome 'code' , which I then use with
       | various esp32 based devices (mostly from M5stack) via
       | esphome/HomeAssistant.
       | 
       | Can this project help me in any way during dev stage before
       | uploading the code to device just to see it doesn't work ? Eg
       | could I use this to somehow compile&run those esphome yamls via
       | this emulator?
        
         | dmcrespo wrote:
         | That's a really interesting use case. I'm currently evaluating
         | integrating the ESPHome compiler into the project, so it could
         | potentially compile and run ESPHome YAMLs during the
         | development stage
         | 
         | It's still exploratory, but it could definitely go in that
         | direction
        
       | urbandw311er wrote:
       | This is a great idea. It's always been inconvenient requiring
       | access to the physical board just to be able to test these sort
       | of projects.
        
       | wumms wrote:
       | Nice work! One minor point for me: it wasn't immediately clear
       | that you need to press Compile before Play gets enabled (e.g.
       | Arduino IDE let's you upload right away and compiles if needed)
        
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       (page generated 2026-03-27 23:00 UTC)