[SuperMouse]

I'm currently thinkering of building a balloon with a 2.4GHz LoRa transmitter (SX128x) and a low-power STM32U microcontroller.

Why?

- You can repurpose 2.4GHz Wifi gear opening many doors

- You can easily include volunteers dumping data from HF into a IP sink for telemetry. TTGO offers boards with 2.4GHz LoRa.

- Theoretically you still can add a "low rate" 868MHz/433MHz and a "high rate" 2.4GHz for transmitting pictures and other stuff more quickly.

- BOM friendly. As the balloon might get lost you have to plan a bit for costs.

[Neywiny]

Why not use the STMs that have the LoRa built in?

[SuperMouse]

Not for 2400MHz LoRa.

For 433/868/915 they are great.

[iberator]

lol. WPRS works like 10.000km per WATT on HF. You can't do it with 2.4ghz.

Ham radio basics

[ErroneousBosh]

Why do they do WSPR on HF and not 2.4GHz?

What's the important part that defines what kind of range you can get?

[SuperMouse]

lol. 10.000km with a few bits of fixed-structure payload you mean.

Encoding basics