Broadcasting LoRa packets wihout a radio [video](youtube.com) |
Broadcasting LoRa packets wihout a radio [video](youtube.com) |
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 transmitter on the aircraft was transmitting telemetry back at 100mW throughout the distance)
Another related fun project is using raspberry pi gpio to work as an FM transmitter: https://github.com/markondej/fm_transmitter
The worst is when someones on your channel using the same modulation as you are. If he's louder he'll blow your packet out of the water. Keeping your packets short and using max power (cheezy grin) and retrying helps.
But even interferers on different channels will degrade your sensitivity and reduce your range.
None of this is unique to lora modulation.
The distinction is quite important because I imagine anything bigger than the tiniest of villages will be swamped with interference..
It’d be an ideal way to create a signal with the potential to reach, say, a large fraction of the galaxy without requiring a Dyson swarm to power the transmitter.
Of course there are so many modulations this might be combinatorially impossible unless we can make some rational guesses about what a rational intelligence would use for interstellar communication if they wanted others to notice.
So which directions you excluding?
The ideal range/speed is somewhere between 100 and 1000MHz, ideally you would want that entire range.
But how do you build a band pass filter that can cover the entire range?!
And imagine that, quality content without “be sure to like and subscribe!”.
>Because we rely on harmonics and aliasing, the primary frequency components emitted by your microcontroller are going to be in portions of the RF spectrum where RF transmissions are banned. Please filter your output or perform your tests in an area where you are unlikely to leak significant RF. The overall EIRP output is genreally ≪300uW across the whole spectrum spread out over hundreds of emission frequencies, but there is virtually no way a device deliberately transmitting on these frequencies could ever pass FCC part 15 compliance, even with filtering.
While low over the whole spectrum, on the desired harmonics the power is higher, just how far does it go. I'd also worry about getting into trouble experimenting with such things. Some wilderness areas utilize radio to track and monitor wildlife and resources, hopefully it wouldn't interfere with those. Though maybe it is not easy to get in trouble doing so because of the low power output.
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 situations. As someone above mentions, LTE on the 800MHz band with 900MHz control links are much more of a problem - I've had a failsafe for that exact reason at <200m total distance from takeoff.
The naysayers, even if they aren't strawmen, weren't "saying" anything of note. There aren't any mysteries or questions here: what can be achieved is predetermined by the factors involved. The key figures of merit are power, gain, path loss, noise and receiver sensitivity. Whatever those factors are determines feasible range, and they are all well understood.