Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Bouncing a LoRa message off the moon

electronics360.globalspec.com

Post reply on HN
Print view View original

41–50 of 71 posts

Re: Bouncing a LoRa message off the moon

#41

Post by snovv_crash »

Breefield wrote: post #5
jmole wrote: post #2

of all the things to bounce off the moon, why a consumer IoT protocol? Alien 1: The humans are talking again. Alien 2: What did they say? Alien 1: The front door is locked.

Just a guess: given that LoRa operates on line of sight, when trying to update a gateways with sensor status (e.g. GPS position of tracked item) the operator won't be able to get realtime reports if the gateway isn't positioned at a high enough altitude relative to the sensor. You can mitigate this by having many gateway/collectors at high points on buildings/hills, but bouncing signals off the moon seems like an int…

LoRa doesn't have to be LOS, it depends on the carrier frequency you use. 900MHz LoRa is used for building penetration of control signals for racing drones, for example, with the open source ExpressLRS system.

Re: Bouncing a LoRa message off the moon

#42

Post by gh02t »

intpx wrote: post #38
intpx wrote: post #34

Earlier quoted context omitted.

Wasn't it designed for sending sensor data from oil wells spread out over vast swaths of land or something? I've always though of it as shortwave/vhf for packets

Maybe i'm thinking zigbee?

Zigbee has always (or at least, for a long time) targeted a mixture of consumer and industrial applications and is focused on relatively short range mesh networks. It does have a lot of consumer uses now, it's one of the big protocols used for home automation. Not sure of the exact history of LoRa, but widely distributed oil well sensors would definitely fit the intended use of LoRa. Agriculture is another good use case.

Low power sensors infrequently reporting (mostly one-way) small amounts of data back to a base station over really long distances is what it was originally designed for, though people have done other stuff with it. Zigbee is all about the meshing AFAIU.

Re: Bouncing a LoRa message off the moon

#43

Post by ricardobeat »

metal_am wrote: post #8

I’m having a hard time seeing what’s special about this. This has been a HAM radio thing for a long time. https://en.m.wikipedia.org/wiki/Earth–Moon–Earth_communicati...

It’s basically Wi-Fi to the moon. At very low bandwidth, but still amazing.

Re: Bouncing a LoRa message off the moon

#44

Post by thedougd »

gh02t wrote: post #42
intpx wrote: post #38

Earlier quoted context omitted.

Maybe i'm thinking zigbee?

Zigbee has always (or at least, for a long time) targeted a mixture of consumer and industrial applications and is focused on relatively short range mesh networks. It does have a lot of consumer uses now, it's one of the big protocols used for home automation. Not sure of the exact history of LoRa, but widely distributed oil well sensors would definitely fit the intended use of LoRa. Agriculture is another good use c…

Zigbee has a serial bus mode that's identical to RS-485 in practice. There were/are so many industrial applications of RS-485 that they could instantly convert to wireless mesh with a zigbee daughter board or chipset. 'Pro' versions had ~1.5 mile range between nodes.

Re: Bouncing a LoRa message off the moon

#45

Post by fortran77 »

giantg2 wrote: post #3
jmole wrote: post #2

of all the things to bounce off the moon, why a consumer IoT protocol? Alien 1: The humans are talking again. Alien 2: What did they say? Alien 1: The front door is locked.

A consumer protocol, but also way over consumer power level (350W). No wonder it's the furthest LoRa message sent. Let's bump it up to 1kW and break the record again...

That was the Effective Radiated Power. The actual transmitter was outputting consumer output levels.

Re: Bouncing a LoRa message off the moon

#46

Post by nogridbag »

gregwebs wrote: post #40

The YoLink products use LoRa for home automation. I am quite happy using their water leak sensors now. You don't need the quarter mile range, but they communicate with low power successfully in situations where higher frequencies might have reflection issues.

I'm also a big fan of YoLink water sensors. I installed them under every sink and have probes going into the sump pumps to detect high water levels. We have a single hub in the basement and it has no issues reaching sensors two floors up at the far corners of the home.

Re: Bouncing a LoRa message off the moon

#47

Post by stavros »

numlock86 wrote: post #13
giantg2 wrote: post #3

Earlier quoted context omitted.

A consumer protocol, but also way over consumer power level (350W). No wonder it's the furthest LoRa message sent. Let's bump it up to 1kW and break the record again...

1kW? Are you crazy??? Let's see 25mW, which is the maximum you are allowed to use in Germany for 868 MHz ...

To be fair, it can do a few km at 25 mW, which is fairly good for consumer range.

Re: Bouncing a LoRa message off the moon

#48

Post by giantg2 »

fortran77 wrote: post #45
giantg2 wrote: post #3

Earlier quoted context omitted.

A consumer protocol, but also way over consumer power level (350W). No wonder it's the furthest LoRa message sent. Let's bump it up to 1kW and break the record again...

That was the Effective Radiated Power. The actual transmitter was outputting consumer output levels.

I thought most FCC rules are based on effective power and that this wouldn't be legal for terrestrial/consumer use?

Re: Bouncing a LoRa message off the moon

#50

Post by s800 »

giantg2 wrote: post #48
fortran77 wrote: post #45

Earlier quoted context omitted.

That was the Effective Radiated Power. The actual transmitter was outputting consumer output levels.

I thought most FCC rules are based on effective power and that this wouldn't be legal for terrestrial/consumer use?

Correct.
Post reply on HN