Hey! Yea I've been looking into energy harvesting a bit as well after watching this video: https://www.youtube.com/watch?v=TGbtzlWb-Kc

Generally the higher frequency you go, the lower range you get as a rule of thumb. It's also harder to design around higher frequency boards, though it's totally doable. That said, I'd love to see how 2.4GHz works out!

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Catbert59 3 days ago | parent [-]

LoRa is absurdly robust.

Someone maxed out the ranging mechanism of the Semtech SX1280 with a 5dBi rubber antenna. He reached 60km with LoS. And there's a report of 90km in a ballooning project.

(https://github.com/StuartsProjects/SX1280_Testing)

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yonatan8070 3 days ago | parent | next [-]

In fact, it's so robust that even when your antenna is a piece of wire hanging off a GPIO of a microcontroller with absolutely no dedicated radio hardware, you can still get several km of range. Truly crazy stuff.

https://youtu.be/eIdHBDSQHyw

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jotux 3 days ago | parent | prev | next [-]

In a previous job I pushed an STM32WL5 on a custom frequency over a private satellite constellation with a relatively large yagi antenna. Over 70k km round trip :D

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mpkendall 3 days ago | parent | prev [-]

Interesting, thanks for sharing! I'm interested in creating some form of live video/image system, thanks for this!

	▲	Catbert59 3 days ago \| parent \| next [-]
		The Semtech modems have several modulation modes which can be configured in great detail.. the datasheet is quite verbose about them. The latest generation of chips (AFAIR not yet released) integrated a mode that allows them to receive on all LoRa speed grades in parallel. Bit like the existing LoRaWAN basestation ICs. I remember reading a datasheet that one (already released chip) is also able to work on 144-146MHz. But that's not what standard Asia (ESP32+LoRa modules) offer. TTGO has AFAIR recently released a super new board that allows this band.
	▲	sciurus 3 days ago \| parent \| prev [-]
		If you haven't seen it, you may be interested in https://www.areg.org.au/archives/210334