Dave Akerman

Many high altitude balloons these days use LoRa, because it’s simple and inexpensive to use in the balloon and in the receiver, and because it offers extra features such as uplinks that are difficult to do otherwise.

For other systems such as RTTY and APRS, the receiver can be a software defined radio (SDR) or a ham radio receiver. LoRa however is different, and requires a specific LoRa receiver.

Fortunately LoRa transceiver modules are cheap and easily available. Essentially, they just need connecting to a suitable computer which sets the frequency and some other parameters, connecting to a suitable antenna, then the module does all the hard work of receiving, demodulating and decoding the radio signal, delivery a packet (sequence of bytes) containing telemetry or imagery to the attached computer.

This article is about how to obtain or build such a receiver and what software to use with it.

Types Of Receiver

As explained, the LoRa module does all of the hard work, meaning that the attached computer can be quite simple. As simple in fact as a basic Arduino or similar microcontroller. Add some firmware and a small display, and you have something that can display the current position of the balloon. Add a GPS module and it can display the distance and direction to the balloon. What more could you need?

Well, you might want to see the balloon on a map. You might want to have on-screen and audio navigation to drive to the nearest road to the balloon.

Or you might be receiving from home, where you might want to manage multiple LoRa receivers so you can receive from multiple balloons. You also want to upload the telemetry and imagery to the online servers so th\at you can contribute to the tracking of someone else’s flight.

All of these are possible, using Arduno or ESP32 microcontroller, or Android phones or tablets, or a Windows PC. Below I describe the devices apps and programs that I have built and shared for you to use.

Standalone Arduino LCD Receiver

This is as simple as it gets – an Arduino Mini Pro connected to a good old text-mode 2-line LCD, with GPS for positioning and a Lipo for power, with USB charging. Simplicity is a good thing when chasing a balloon, and something like this will find your payload with very little fuss.

That photo is from during the build, before it got an Apple-esque single pushbutton for all functions, including frequency selection.

For more information, see my blog article and the github repository.

I want you to take great care of this equipment, Mr Bond.

If the above is a bit too boxy for you, how about chasing a balloon with a watch?

This is the TTGO TWatch2020, which doesn’t contain a LoRa module (their earlier but bulkier watch did), but does have bluetooth meaning it’s easy to link to a TTGO T-Beam which has LoRa, GPS, ESP32 processor and LiPo battery in one package. So the watch does the user interface stuff, allowing choice of frequency etc., and displaying the position of the balloon and the distance and direction to it, while the T-Beam (pictured in a 3D-printed box and attached to an aerial) does all the radio and GPS stuff.

See my blog post for details, plus the watch firmware and T-Beam firmware.

Raspberry Pi

Using a single or dual channel LoRa expansion board, it’s easy to build a LoRa receiver based on any Raspberry Pi (aside from the Pico). Uputronics sell a single or dual channel board for which I wrote the Pi LoRa Gateway program.

This is a popular choice for fixed receivers. The software is open source and provides the ability to tune in to, receive and upload both telemetry and images (SSDV). This is the oldest and most capable LoRa HAB receiver software available. Also, it can be linked to the HAB Base software below.

USB OTG Receiver

This is a commercial device that integrates a LoRa module with a pre-programmed microcontroller, for connection to an Arduino phone or tablet, or a PC, to provide a complete receiver setup including mapping and uploads to the central map and imaging servers.

The device is available from Uputronics, and by purchasing you are helping to fund development of the supporting software below:

• HAB Explora for Android Phones
• HAB PADD for Android Tablets
• HAB Base for Windows PCs

HAB Explora

Currently this targets Android only; if you are an iOS user then please get in touch. Its aim in life is to make it easier to chase balloons, by showing the position on a map and by providing navigation via phone navigation app.

Data sources (i.e. sources of balloon telemetry/imagery) include the LoRaGo product above, plus a DIY solution using my firmware. The app is free to use, with funding for development coming from sales of LoRaGo and my BuyMeACoffee account.

HAB PADD

Currently this targets Android only; if you are an iOS user then please get in touch. Its aim in life is to make it easier to chase balloons, by showing the position on a map and by providing navigation via phone navigation app.

Data sources (i.e. sources of balloon telemetry/imagery) include the LoRaGo product above, a DIY solution using my firmware, UDP (e.g. from auto_rx for Sondes), and up to two LoRa Pi Gateways (see above). The app is free to use, with funding for development coming from sales of LoRaGo and my BuyMeACoffee account.

HAB Base

This is a Windows program designed to make it easy to manage one or more LoRa receivers at a base station. If you want to use LoRaGo with a PC, this is for you. If you want a nice GUI to manage your Pi LoRa Gateway, this is for you. If you want to centralise control of multiple LoRa receivers, this is definitely for you!

For more information. see this article.

Again, this is free software, so donations are welcomed !