Meshtastic and LoRa

[dogmush]

I know we have some nerds on here, so I thought I'd ask this.

My buddies and I are looking at getting a stand alone coms system set up in our local area for emergency use.  (Think Hurricanes, tornados, maybe localized rioting, not TEOTWAWKI)  We want to be able to talk to the group and help out/share supplies if the cell network and power goes down.

One of the ways we will be doing this is to try and set up a LoRa mesh network between our houses and use Meshtastic messaging app on our own channel.  There are going to be some hurdles with distance and terrain to get a good mesh set up, but we think it's doable.

In that vein I've ordered two Haltec V3 boards to flash and play with.  They should get here tomorrow so I can play with them this weekend.

Anyone ever done any radio mesh networking?  Had any successes and or issues?

We'll be addressing medium range voice communications separately.

[Ben]

I know nothing about it, but have you checked out S2 Underground's youtube? He does a lot of tutorials on this kind of stuff.

[dogmush]

Yeah I went down a YouTube Rabbit hole the last couple of days.  I'm ready to get the hardware and start experimenting.

There's some really cool solar powered repeater node builds out there, if you can find people that will let you put them up high somewhere.

[dogmush]

So follow up:

I got the boards and flashed them to run the firmware.  It was super easy to get them up and running, and pass encrypted coms between my phone and tablet.

Step 2: I mounted them in little Plano boxes with a USB battery pack and started moving them apart.  With the craptastic antenna that comes with the board (~3 SWR at the frequency range I'm using) and .21 W transmit power I put one radio on the top of a truck at work (~15 ft high) and the other on the dashboard of my car and drove away.  This was in Tampa proper so multi story buildings.  I got 0.3-0.4 miles away before I lost the ability to send messages, and the node dropped completely by 0.45 miles.  I'm thinking I could get a solid 1-1.5 miles with just good antennas and maybe mounting to the roof of my car.  Obviously less urban areas would help LOS.

Now I'm seeing how long the boards run on my little 5000mAh battery packs. and we'll go from there.

Off the top of my head: this would be awesome for a group of folks living and operating in a small to medium town. You could pretty easily set up a mesh that covered quite a bit of a city with "base" nodes on houses or other high points, and "travel" nodes with each person checking in with the "base" nodes as they travel.  An ad-hoc private cell network.  If you care to be all tactical you can run ATAK encrypted over this network, or just have a storm/power outage/mutual support group commo network. 

The other thing I'm going to experiment with is putting one of these in my bag, one in the wife's bag, and a GPS enabled one on the dogs when camping.  If a dog runs off after a creature or whatever, being able to ping their GPS anywhere within a mile or two and plot them on a map regardless of cell coverage or Commercial "Dog GPS Tracker" plans seems handy to me.

The whole thing is low power enough that you can build a node with a couple 18650 rechargables, and a 15W solar panel and it'll run indefinitely.  So remote/low maintenance nodes are a pretty easy thing.

[cordex]

Definitely something I've been thinking about, but they'd have to be stupid easy to use given most of the people around me that I'd want to be able to communicate with aren't particularly tech savvy.

How small are the units you'd mount on your dogs?  That's another neat idea.

[dogmush]

Once running the App is stupid person simple.  Bluetooth to the Node (in the app) and message in the app.  All the mesh handoffs are done in the background.  Flashing the firmware was pretty easy, but requires the ability to run a laptop and flash a microcontroller.  The Meshtastic Firmware is in a package and has an online flasher, so it's easier than an Arduino flash.  Once it's set up though it's super user friendly.  If you want it use it as an ad hoc modem for another app (ATAK for example, but there are others) you will need to be able to manage app plugins, and maybe sideload stuff to your device.

Dog nodes will be 2"x1"x5" (including antenna).  I'll drop it in a pouch either velcroed to their collar, or molle'd to their harness.  (Both pups have some Blaze Orange for wandering around in the woods, so they have vest space available.  They are also not purse dogs).  Dog Node: https://meshtastic.org/docs/hardware/devices/techo/ 

I could build a smaller one probably, but by the time I design and print a case for a smaller board, install the GPS chip, buy and use a COTS battery solution and put an antenna in it, I'm not saving much space or money.