Meshtastic

I'm just digging in to it and setting up "Rnodes" with my heltec v3's and sending files and voice is cool.

The nomad network is a markdown internet, and it all works over Lora or any other network.

Lots to learn still but it looks promising as a mesh data network.

I'm interested in this project, but I am unsure if there's anything actually useful or fun you can do with it.

So tell me about the fun stuff you've built!

I have just unpacked and flashed my new t-deck and I'm very excited! Sadly, i had to use some google drive provided old firmware (2.5) since I can not figure out how to find(, build) and upload the firmware.

Having worked with esp32s in the past, i know of the many different ways to flash them (platform.io, webflashers, esptool, etc) but I'm missing something.

Where is the "fancy ui" actually from and how do you build it? I was just told to clone, build and upload the latest from github. (https://meshtastic.org/docs/development/firmware/build/) but that just flashes the crappy ui which I have no idea how to use.

Very thankful for any help! Thanks!

(alt text: picture shows t-deck with "fancy ui" and a chat of two people sending test messages, indicating that it works)

I have just unpacked and flashed my new t-deck and I'm very excited! Sadly, i had to use some google drive provided old firmware (2.5) since I can not figure out how to find(, build) and upload the firmware.

Having worked with esp32s in the past, i know of the many different ways to flash them (platform.io, webflashers, esptool, etc) but I'm missing something.

Where is the "fancy ui" actually from and how do you build it? I was just told to clone, build and upload the latest from github. (https://meshtastic.org/docs/development/firmware/build/) but that just flashes the crappy ui which I have no idea how to use.

Very thankful for any help! Thanks!

(alt text: picture shows t-deck with "fancy ui" and a chat of two people sending test messages, indicating that it works)

So there is a router 3.7 miles from my house that i can hear between 2 and 5 SNR but its hearing my transmissions between -4 and -18 SNR with a -10 average (5 traceroute tests). Shouldn't it be able to hear me just as well as I can hear it? I can only think of two possible causes for this.

1. The router has a much higher noise floor than I do
2. The router antenna is more than 33cm tall and has directional lobes and null zones.

However, that second explanation seems off simply because if it wasn't transmitting my direction, I shouldn't be able to hear it as well as I can.

Thoughts?

Edit:

3. My antenna is not a full 33cm So does not radiate the signal efficiently.

So I just saw a video where somebody made a bulletin board system over the mesh like it's fucking 1999 or something and it got me thinking Would it be possible to send web pages over the mesh as long as they were small?

I went to the DuckDuckGo homepage and copied its HTML source code into a text editor and found out it was something like 46,000 characters and with a 288 character limit it would take 145 messages to send that across. Each message would be something like 0.69% of that page.

It doesn't seem impossible, but you would have to make your pages very lightweight like they were in the 1990s in order to do it efficiently.

In densely populated areas, such as cities, it seems like it would be more advantageous to use shorter, faster presets, such as MediumSlow, MediumFast, ShortSlow, or ShortFast instead of the default LongFast.

How would you go about connecting these together without using the internet? I think MQTT could do it, but that would require at least one server somewhere that has no net connection and one radio for each speed. Is there another way that I might be missing?

I think you would also have to be careful with how much data you put onto the slower speed network.

Edit: example: MediumSlow is 82% faster than LongFast.

Last night, my node showed that it received information from a node 100 miles away, and I dismissed it as just a weird artifact. But tonight, my node is showing that there are three nodes that are around 220 miles away. I do not have MQTT enabled on downlink so they are definitely over RF. But how is that even fucking possible? I live in an area where the mesh is not super well built up and there are only a few people locally that have nodes and I would expect to get nodes from a lot closer than 200 miles away or even 100 miles away considering there are two decently large cities only 70 miles away. Also, so far I have only gotten these messages at night.

Edit: Correction, they are between 270 and 320 miles away.

I just bought a SeedStudio SenseCAP T100-E. I only see 1 node in my area on meshmap.net and doubt i will be able to hit it. I will just have to add myself to the mqtt map to let others know a new node exists in my area.

I got a LoRa hat for Raspberry Pi and my Pi 3 is broken, so I'm wondering if anyone has tried it on a Pi 2. I don't see it mentioned on the site and whenever I try installing meshtasticd it fails because of dependencies (not sure if that has anything to do with the Pi, but figured I'd bring it up in case.)

I've been reading a bit of the documentation before I get started. Meshtastic's target use case still seems muddy to me.
Between the different frequencies and modulation modes you can use that don't immediately seem interchangeable, it seems to me that Meshtastic is more meant for you to build out your own local mesh network with consistent settings, vs. a resilient WWAN mesh network covering your town or entire city utilizing stranger's nodes.

Am I misinterpreting that? Is there a "common" frequency/repeater setup that most people use to create a public node that would let me contribute to a network in my town? If it's something that can be used for that, maybe creating a communication network that could survive a largescale interruption in power/telecom (either political or physical in nature), I'm so down for it.

I'm still definitely going to get some hardware and likely set one of these up on my parent's ranch, with bluetooth repeaters in the vehicles to allow communication where cell service sucks. But I do need help understanding it's usefulness to a public service.

I'm going to do some a/b testing to compare to the rubber duck antennas I've been using. I don't expect much more, but perhaps a little bit more range?

Going from the little stubby coil of wire included with the heltec v3s, this should be amazing.

Edit: I tested it and it works just fine, or at least within the margin of error of my test. It wasn't significantly better or worse than the Amazon bought high gain rubber duck antennas, a little disappointing but 🤷‍♂️

As has been said before, height is might. Line of sight counts for more than increased power.

I'll still probably use them on some permanent nodes 🤷‍♂️

Just putting this here in case it's useful to someone else.

I'm still working on setting up my local nodes and meshing to my buddies houses. Part of my testing involved going to the top of the tallest hill in my town, (1300 feet above ground level, the rest of the ground is relatively flat around here).

The problem was that I couldn't connect to my home node, around 2.5 miles away, good line of sight. Testing showed that my home node received all my messages, but the return confirmations never made it back.

The problem? The tallest hill in town is also home to two fully loaded cell towers, blasting away, presumably deafening my node, overloading the front end with strong out of band signals. 900mhz GSM perhaps?

At any rate, I looked into band pass filters. I'm a ham and I've dealt with poorly filtered front ends by the likes of baofeng, so I know filtering can do a lot, and I wasn't sure how much a standard node came with.

The answer? Some, not much. Enough for most use cases. Oddly, most information I found on the subject, specific to Lora, advocated against using filters, saying they are usually unnecessary, etc etc.

While that's probably true most of the time, it's definitely not true all of the time. I'd be interested to see some a/b comparisons of 20-40 foot high nodes in urban environments, both with and without filters.

From experience I know that a baofeng 144mhz radio (known to have poor filtering) with a 1/4 wave vertical antenna up 40 feet, was mostly deaf to any distant signals, and actually performed better in some instances by just using the stock antenna and standing on the ground. Likewise when using the 40 foot tall antenna and adding a filter, the reception was massively improved.

Add to that experience my most recent test. I added a 915mhz band pass filter to my node and brought it on top of the hill, next to the cell towers, and was able to make full duplex communication with my home node.

I'll be doing more testing, some a/b testing with the filter on my home node to see if it improves my range tests.

Filters probably aren't for everyone. And they aren't free performance gains, you can't forget insertion loss. But don't be afraid to buy one and try it if you think you might be having desense issues.

Hear me out. I've been thinking about the best way to put up solar nodes in my area.

I live in Michigan so the winters are long and usually cold, and can get quite cold on occasion. Less so these days, but still. We all know that lithium doesn't like to be charged below 32f, so that's a problem.

I have one idea for a remote node on my property, to just use a 6v sealed lead acid with a 6v solar trickle charger, maybe a diode in series to the node if the voltage from the panel threatens to go over 7 or 8 volts. Or some kind of shunt, idk that idea isn't fully baked.

I'm also looking into a thermostatically controlled resistive heater. Bump up the capacity of the battery and make sure the panel is big enough to run the heater non-stop if need be. But that idea is also still baking, parts are in the mail and prototyping is yet to be done.

But then I had another idea. What about super capacitors? You can get a 5.5v 10F super capacitor on Amazon for $6. Some chatgpt math (and a proper understanding of the difference between power and energy, or rather ma vs mah) tells me that the storage 10F at 5 ish volts is equal to a nominal lipo at 3.7v and 10mah. Ignoring the fact that the capacitors voltage would drop sooner, and thus you'd lose some energy on the bottom end...

The T114 v2 has a built in solar charger circuit, a standby current of 9ma, and a TX draw of 150ma. So with a super capacitor you could get roughly an hour of idle time, or 4 solid ish minutes of nonstop transmitting. That's more than enough to account for a big cloud passing by, especially if you beefed up the solar panel, or easier yet just doubled or tripled the capacitors, they are pretty small.

The charging circuit might not like the low internal resistance of an empty capacitor every sunrise, but a couple ohm resistor in series would probably solve that.

Yes it's not ideal to have your nodes turning off every night, especially in the winter when days are short to begin with. But could it technically work? I feel like it could technically work. It'd be great in the summer,

My only concern would be the node getting stuck in a weird state if the sky is cloudy and the CPU browns out. It'd take a whole day to power cycle. Probably put a megohm resistor across the capacitor to ensure that it drains fully overnight in that scenario.

Are there any concerns with constantly hard power cycling a node like that? Data corruption?

The lead acid is probably the safest solution, though heavy. And the heater is probably the most compact solution, though more complicated and prone to catastrophic failure. But maybe there is room for super capacitors?

Sorry for the wall of text. Just spit balling.

Edit: HOLD THE PHONE! You can get 500F caps for $7! The reviews say they're actually more like 300F, but even that could idle a node for well over 24 hours, and TX nonstop for 2 hours, which is unlikely to happen. This is a game changer. This could solve the winter lithium problem.. I'm going to try this and I'll report back.

Edit 2: Various super caps and LiCs still on order. But I just came across this in the discord:

"Dendritic degradation happens when charging below freezing. However it’s a slow process. And the slower the charge, the longer the lifetime. With IoT devices the charge rate is quite low and not as critical compared to higher draw devices. Up here winters reach -40 sometimes, and in a lot of cases it sits below freezing for weeks, even months at a time. We’re now in our second winter on the same batteries with no failures (yet). Regular lithium Ion and LiPo. I’ve only done LTO for high traffic nodes that are very hard to access. Otherwise just plan to replace them when they die.

Slower the charge rate / the higher the capacity / the newer the battery / the better the quality the battery, all compound into longer cold weather performance.

There’s other factors too, like the higher the charge rate usually means the more sun/solar activity, which also means if you have a properly setup enclosure, the sun hitting it can be enough to increase the temp by over +20c or even more. This also doesn’t account for the charge/discharge heat being released by the batteries themselves in the enclosure." -Cully@KBOXLabs

So it seems to me I'm overthinking this whole thing.

Maybe a super cap or LiC would be good for extreme longevity. But a decent pair of 18650s might be plenty for something you won't have to touch for a couple years 🤷‍♂️

I'll still do some testing and report back, but I might not spend the extra money making each node supercapped.

I'm still fighting with Amazon to get my first pair of devices delivered, I went with heltec v3s to get started.

But looking at the meshmap.net, it's very very sparse around me. How likely is it that the are nodes that aren't on the map?

Hopefully I can check it out myself soon!

I mean, your smartphone already knows how to talk on 600 megahertz, 700 megahertz, 800 megahertz, 1.7 gigahertz, 1.9 gigahertz, 2.1 gigahertz, 2.4 gigahertz, 3 gigahertz, 5 gigahertz, 6 gigahertz, etc. I see absolutely no reason it would be unable to talk on 915 megahertz.

I have been an amateur radio operator for quite a long time and am starting to look into meshtastic and the Lilygo T-Deck. However, their site asks me which version I would want. The 915 megahertz, the 860 megahertz, or the 433 megahertz. As an amateur radio person, the 433 MHz would be the lowest frequency and therefore should be the longest range, but is that the most popular model? Would I be missing out on nodes if I were to use 433 MHz instead of 860 or 915?

Supplemental video by the creator of the blog post: https://www.youtube.com/watch?v=2Ry-ck0fhfw