2025-09-12 –, Ballroom 2
WebHorus and WebWenet are entirely browser based implementations of the Horus and Wenet radio demodulators which are commonly used for receiving amateur high altitude balloon telemetry and imagery. By producing web versions of these tools, it has significantly lowered the barrier of entry to set up a receiver. It's even possible to receive on a mobile phone connected to a USB software defined radio!
We'll be running through how we compiled the C applications into Python modules, built the Python modules for WebAssembly and finally how they are called from JavaScript. No server involved. Packaged into a progressive web app that even works offline.
Python is quickly becoming my favourite web programming language while HTML and PWAs are becoming my favourite way of distributing Python applications. Historically, a lot of the amateur balloon tooling has been based around compiling C apps, piping a bunch of binaries into each other, and hoping for the best. More recently, Project Horus has been moving to using Python to orchestrate the applications and in some places building Python libraries to interface with the C code.
What started as a joking "what if" turned into an entirely usable web application. First, harnessing the Python CFFI library to make Python modules for the C apps. Then by using Pyodide to bring these into WebAssembly, we've been able to get users decoding balloon data in their web browser, without them compiling or installing any apps.
