Broadcasting LoRa packets wihout a radio [video]

Post by eternityforest » Wed, Mar 27, 2024, 7:48 PM UTC

thijson wrote: post #4

saidinesh5 wrote: post #3

I really liked the explanation of how he used harmonics to get to the frequency he desired. Also, LoRa is really good when it comes to low power data transmission. To share a recent example, with just ~100mW of transmission power, they managed to fly an RC plane to a distance of 100km: https://www.youtube.com/watch?v=CYJ2UOrlXgM .(Their transmitter from the ground station was configured at a higher power, but the tra…

I looked a bit into the LORA protocol. It does offer reception below the noise floor. LORA doesn't do anything to attempt to make other LORA transmissions seem like noise to a receiver that's attempting to lock to your transmission. This makes it possible for a transmission that's closer to the receiver to essentially jam a transmission that's far from it. I guess since LORA isn't used that much, it's not a problem t…

Post by FrankPetrilli » Wed, Mar 27, 2024, 9:59 PM UTC

topspin wrote: post #7

saidinesh5 wrote: post #3

I really liked the explanation of how he used harmonics to get to the frequency he desired. Also, LoRa is really good when it comes to low power data transmission. To share a recent example, with just ~100mW of transmission power, they managed to fly an RC plane to a distance of 100km: https://www.youtube.com/watch?v=CYJ2UOrlXgM .(Their transmitter from the ground station was configured at a higher power, but the tra…

Doesn't LoRa have a pretty constrained duty cycle? I read the regs on LoRa (for the US at least) and found that you're required to limit transmission frequency to 1% (36s/h). I'm guessing you'd have to go well past that to operate an RC aircraft in the conventional manner. If you're just commanding waypoints I suppose you could be compliant.

Post by jorvi » Wed, Mar 27, 2024, 10:36 PM UTC

FrankPetrilli wrote: post #32

jorvi wrote: post #9

Earlier quoted context omitted.

Were the naysayers saying 2.4GHz was impossible at all, or were they saying in a normal setting? The distinction is quite important because I imagine anything bigger than the tiniest of villages will be swamped with interference..

In particular, people used to plain FSK RC protocols like Spektrum DSM, FrSky D8, Futaba FASST, and similar which tend to failsafe around Also notably, LoRa does tremendously well with real-world noise and interference. Of course any receiver is susceptible to frontend overload, but in "normal" situations I never worry about flying 2.4GHz even in crowded cities, and have never had a failsafe even in some ridiculous s…