I don’t use MQTT currently, but there’s several things you can do with it:

• Pass some messages as plaintext for use in, say, HomeAssistant
• Bridge meshes over the internet
• Send/receive ProtoBuf messages from an MQTT client to the Meshtastic node and the mesh
• Plugging in some of the mesh mapping programs to visualize the mesh

I tried setting up MQTT with HomeAssistant but couldn’t get messages to come in correctly. Most likely my own fault but I just never got back to it as I didn’t have a specific need in mind when I was setting it up.

Most of what I’ve dealt with were ESP32-based devices like the Heltec V3 (now V4) that have integrated LoRa radios. It should be possible to add on a SX1262 LoRa radio via SPI and flash Meshtastic firmware, but most people just start with a pre-built kit since they’re pretty inexpensive and have battery charging circuitry and everything already onboard (which you’d otherwise have to handle yourself with a vanilla ESP32).

I started with the Heltec V3, and the V4 improves several gripes I had with it. They’re easy to get started with, lots of case designs available, and generally good entry points.

SeeedStudio has a lot of pre-built options as well. My new daily driver is the SenseCap T1000e which is about the size of a few credit cards stacked together. Posted about it here: https://startrek.website/post/34105873

There’s two main flavors of Meshtastic devices: ESP32-based and nRF-based. The former are generally a little less expensive and have WiFi but are a lot more power hungry.

The nRF-based ones are more power efficient and can run longer from smaller batteries. The tradeoff is those only have Bluetooth and lack WiFi. I don’t really use WiFi with these, but it can be useful if you want to connect a node to MQTT.

Check out Seeed to see some of their pre-made options: https://www.seeedstudio.com/LoRa-and-Meshtastic-and-4G-c-2423.html

Definitely one of the “throw it on the pile” projects for me, too, but I’m for sure throwing it on the top of the pile. Have had quite a few severe storm warnings this year already and this could be pretty useful. I was originally just looking for a way to forward NWS/EAS alerts to Meshtastic from the internet, but getting them direct over-the-air is even better.

Only complicating factor is I have to fashion or buy an antenna for ~150 Mhz since I don’t have any adapters that will fit the RTL-SDR (I’ve just used the little stock UHF TV antenna that came with it for ADS-B and other playing around).

AFAIK, yes, memory. There are a lot more packets than just text messages. Telemetry, node info, positions/waypoints, etc.

This is from memory and anecdotal, so take it with a grain of salt.

On firmwares below 2.7, I think it only stored the last-received message on the node itself. 2.7+ may store the latest message from up to a few different contacts, but not more than that (if even that). Either way, it’s not really meant to operate as a “mailbox” where you can retrieve the messages later; they basically need to go somewhere as they’re received.

There’s a store-and-forward mode that can be enabled, but it stores all messages for everyone and is more of an infrastructure node role. It also requires hardware that has PSRAM which the Heltec V3’s don’t have.

Truth.

I just see those devices as mesh extenders waiting to happen lol.

I don’t even remember how I learned about Meshtastic. It was just one day I’d never heard of it and the next day I was obsessed and had multiple radios to play with. How I got there? Total mystery.

The irony there is that there’s a link between microplastics and Parkinson’s.

https://www.nih.gov/news-events/nih-research-matters/nanoplastics-may-help-set-stage-parkinsons-risk

You definitely want the batteries in a conditioned space. You didn’t say what type of batteries, but I’m assuming LiFePO4. You can store them at a fairly wide range (my hybrid battery does fine all winter parked outside) but charging/discharging them has much more restrictions if you want your batteries to remain healthy and happy.

• Discharging Range: Typically from -20°C to 60°C (-4°F to 140°F). This is the widest and most permissive operational range.
• Charging Range: A much stricter range, typically from 0°C to 45°C (32°F to 113°F). Respecting this range is critical for battery health.
• Storage Range: The ideal range for long-term health is between 10°C and 35°C (50°F to 95°F).

– https://www.anernstore.com/blogs/anern-solar-insights/lifepo4-battery-temperature-range-guide

Those are “absolute” limits but there’s a table on the linked page with the recommended temperature limits and they’re quite a bit more narrow.

Whether it makes more sense to condition the shed or run your PV output 30 meters from the shed depends on the amperage and voltage from the PV. The higher the voltage, the less amperage and thus smaller conductors can be used and less loss along the way. Not sure what your charge controller accepts, so you’ll have to check.

Nice. I’ve got the Anker version but it’s half the capacity at 1 KWh. It charges exclusively from 800W of PV input (though it can only handle 600W input) and can push out 2,000 W continuous and 3000 peak.

I’ve got a splitter from the PV that goes to both the Anker and a DC-DC converter which then goes to a few 12v -> USB power delivery adapters. Those can use the excess from the PV to charge power banks, phones, laptops, etc while the rest goes to the Anker (doesn’t seem to affect the MPPT unless there’s basically just no sunlight at all). Without the splitter, anything above 600W is wasted until I expand my setup later this spring.

All I can say for it is that it absolutely rocks! On sunny days, I run my entire homelab from it, my work-from-home office, charge all my devices, and run my refrigerator from it if I feel like running an extension cord). It’s setup downstairs, so I also plug my washing machine into it and can get a few loads of laundry done as well.

All from its solar input.

To give perspective with a 3000 mah battery I am still lasting days.

Is that connected via bluetooth or just running the LoRA radio? Curious if the V4 is any less power hungry than the V3. I never did a rundown test with one of my 3,000 mah V3 units, but my daily driver had a 2000 mah battery and barely made it 14 hours before it was throwing the battery low warning. I kept it connected to my phone the whole time under most conditions.

Same conditions but with the nRF-based T1000e, it runs for about 2 days on a 700 mAh battery AND has GPS (I didn’t have GPS on my daily driver node). The difference is amazing.

Could be any or all of that, yeah. You can also set the level of precision for your reported location, but I don’t think even the lowest precision settings would put it 1,000 miles away.

I live near-ish to an airport, and I’ll occasionally see nodes that are 1 or 2 hops and 100-200+ miles away. Best I can tell, the airborne node is legit relaying those which I think is pretty cool. Not really useful, but cool.

LoRa is a proprietary radio interface, so I don’t how how FOSS you can go with it, but the Meshtastic firmware itself is FOSS.

What are your use-cases? Are you looking for something to use as an everyday carry? An outdoor solar node to relay messages in your area? A node to use as a base station? All of the above?

For everyday carry, I semi-recently bought the SenseCap T1000e and I love it. I did a post about it here: https://startrek.website/post/34105873

Seeed (the company that makes the T1000e) also makes a nice outdoor, solar powered node: https://www.seeedstudio.com/SenseCAP-Solar-Node-P1-Pro-for-Meshtastic-LoRa-p-6412.html

They’ve also got a lot of options for various other configurations as well: https://www.seeedstudio.com/LoRa-and-Meshtastic-and-4G-c-2423.html

Those are all “turnkey” devices, but I’ve heard good things about the Heltec V4 if you want to go a more DIY route and make your own case and add your own accessories (GPS, accelerometer, etc).

It’s theoretically possible but probably not practical.

There is a maximum hop count of 7 which means there can be, at absolute maximum, seven nodes between the sender and recipient. The default, though, is 3 hops.

While the radios may, in theory, be able to work at the range of “a few states over” as the crow flies, terrain, structures, and line of sight would likely prohibit them from working in practice at such distances. You’d also need a reliable series of hops to reach from you to them. Again, at those distances, you’d very likely exceed the maximum hop count pretty quickly.

From what I’ve seen, large meshes are generally regional.

There’s a way to join meshes over the internet via MQTT but I haven’t messed with setting that up and in some cases it can potentially overwhelm a local mesh.

My knowledge is incomplete as to what powers and restrictions you get with an amateur license, but I think the only real reason you’d want to use HAM mode in the US is if you wanted to operate on US 433 or maybe the 868 MHz block. Not sure if HAMs have access to the latter one or not, though. The 915 block is pretty permissive here for unlicensed use, so that’s usually sufficient.

Also, if a node is operating in HAM mode, it may not be able to mesh with other nodes not in HAM mode due to encryption being disabled. I could be wrong about that as I haven’t read into that specifically, but to my knowledge it tracks.

AFAIK, you only need to use it in HAM mode if you want to use licensed frequencies, a higher power transmit (assuming the radio supports it; US 915 can transmit up to 1W/30db and many radios only transmit at 22db max), or to go beyond the airtime limitations (no limitations on US 915). HAM mode also disables encryption if I recall. Also AFAIK, you’re not required to use HAM mode just because you are a licensed HAM operator.

Sources: Have read the docs but am not a licensed HAM.

Any new contacts? I’d always guessed that boats would likely be running nodes.

the remainder of the post contains references to reddit which may cause apoplexy in some viewers. :-)

Heh, I always forget about client_base. My device in that role is still on firmware 2.5.0 from last year and doesn’t have client_base as an option. Gotta get it updated stat lol.

Check out the SenseCap solar node. It’s way under $200 and professionally built.

https://www.seeedstudio.com/SenseCAP-Solar-Node-P1-Pro-for-Meshtastic-LoRa-p-6412.html

Probably the best configuration for it is as a regular client since that will relay like a repeater but without forcing other clients in the mesh to use it (which would be problematic unless you’re in a super ideal position).