Mastodawn

Have my own little #meshtastic node now, and I have no idea what I'm doing. I already want to upgrade my antenna.

Paul Fenwick Jun 21

Genuinely impressed with #meshtastic thus far. I've got a pair of ThinkNode M2s, and the antennas that come with them are literally bits of printed circuit board, and yet they've managed to get a surprising bit of range (maybe 300m) out of them with suboptimal placement and no special care.

I can see that with a real antenna and an elevated position they'd go quite well.

https://meshtastic.org/

Meshtastic

An open source, off-grid, decentralized, mesh network built to run on affordable, low-power devices

Paul Fenwick Jul 3

Whatever stroke of luck that was giving my #meshtastic node access to the rest of the mesh is gone. Until yesterday there was an otherwise silent node out there that was forwarding packets to and from mine.

I'm now anxiously awaiting my new antenna to arrive, because it feels wrong for my tiny radio child to be cut off from its friends.

Paul Fenwick Jul 4

Baby's first solar powered LoRa #meshtastic node.

Still waiting on a better antenna.

Paul Fenwick Jul 5

…and the battery that comes with the M2 board is *almost* enough to power it through the night. It would probably be fine in summer.

Luckily batteries are pretty inexpensive as well.

Paul Fenwick Jul 5

I'm too impatient to wait for a larger capacity battery, so I'm disassembling an old laptop battery to see if I can find any usable cells, and if I can scrounge a lipo protection circuit from somewhere to go with said recovered cell.

Paul Fenwick Jul 5

Aha, looks like I need Maximum Power Point Tracking (MPPT) doodad for charging off a solar cell, and I doubt my $10 panel already has one integrated.

If I understand correctly, an MPPT doodad lowers the current draw from the panel to maintain enough voltage to charge; otherwise the battery charger can try to draw too much, which drops the voltage, and one gets nowhere.

A random blog post recommends a CN3791, which are only a few dollars, so I shall continue investigating

Paul Fenwick Jul 9

I've been trying to understand how antennas work, and it's all deep eldritch shit. Make sure your antenna is an exact fraction of the length of the silent whispers you wish to hear from the void. Make sure the antenna has a solid plane to bounce the whispers off, but somehow you can get away with just a couple of wires that suggests where a solid plane would go. Make sure your cable isn't a cursed length, which attracts unwanted attention.

RF engineers are heckin' magicians.

Paul Fenwick Jul 9

I really feel like #meshtastic would be an awesome thing to get high schools on board with, even if just informally.

If most schools had a node on a high building they'd mesh really well. Students could create their own channels, giving them a resistant, capitalism-free way of communicating as individuals and groups. Advertisers and social media bans can piss off, as students can create and manage their own networks.

Paul Fenwick Jul 11

Yesterday a new node showed up on #meshtastic with a huge amount of signal.

After some quick introductions it turns out we live in the same street. That got me invited to a group of radio nerds, and I'm going to a build day tomorrow to expand our local mesh.

This is how normal people make friends as adults, right?

john fink ok!! :goat:Jul 11

@pjf that sounds DELIGHTFUL, man. I hope you have a terrific time.

@pjf following this development with interest (looks pointedly at new LilyGo T-Echo sitting just beyond the keyboard whose mysteries are still an enigma to me)... have fun regardless!

WearyBonnie Jul 11

@pjf
It's how they wish they would make friends as adults, at the very least 😍

Cavyherd Jul 11

Oh hell yeah, this is an excellent way to make friends. Might actually be mil spec community building.

Ludwig Vielfrass Jul 11

@pjf This Is The Way.

Jon A. Cruz Jul 9

@pjf ooh, very good point. I was thinking this might be like the peppers in the '80s... but then recent events here in LA came to mind.

Get them kids going! Oh, and maybe have them read Little Brother.

Dimly Lit Corners Jul 9

@joncruz @pjf I would suggest going with #MeshCore or even #ReticulumNetwork instead? Better performance, better features, less security issues

Paul Fenwick Jul 9

@joncruz : The Red Hot Chili Peppers were used as a resilient communication network for teenagers in the 80s? I missed out on so much!

Possumantha Jul 9

@pjf @joncruz really? What did you think F.L.E.A. meant?
Florescent Lensing Emissions Antena

Jon A. Cruz Jul 9

@pjf preppers. Stupid auto correct

Paul Fenwick Jul 9

@joncruz : Aww, preppers are way less exciting! I was all ready for some esoteric RHCP lore! ❤️

Jon A. Cruz Jul 9

@pjf hmmm... not sure if have more than the fact that he got together with Frank-N-Furter to do cartoon voices that my kids grew up with.

Paging @StefanEJones, this notion seems at least your-wheelhouse-adjacent?

@pjf This is an interesting idea which Safeguarding would veto in an instant. There are so many ways this could go wrong. School-provided tech has to be locked down to ensure most communication is restricted and all of it is monitored, as schools have a very strict legal duty to ensure the safety of their students. Ours is set so student accounts can't even email outside of their own school, and emails within are run through monitoring software that flags emails with key words for human review.

Kit Bashir Jul 10

@pjf my (yr12) kid and their bff were deeply intrigued by both meshtastic and CB when their school banned cellphones.

Schools in this country will never touch a tech they can’t censor, alas.

Jim Campbell Jul 9

Remember when CB radios in cars were the knees of the bees?

People would be talking about SWR like they were a descendant of Marconi!

@pjf If you want some proper black magic look up left handed metamaterials. These unnatural materials do everything backwards. They can be used to make cloaking devices. Googling produced a paper called "Quantum levitation by left-handed metamaterials".

Paul Bone Jul 9

@pjf Has anyone tried putting their antenna(s) into a pentagram? It doesn't seem either more or less silly than other RF stuff. Or HF stuff on circuit board design.

John Deters Jul 10

@pbone @pjf The KrakenRF direction finding SDR requires you to place five antennas in a perfect pentagram on the roof of your car, then drive around to locate an evil transmitter (encircling the transmitter is not technically required, but can be satisfying.) Once enough chanting has occurred, the Kraken will guide you to the summoning point where you can bring the demon scourge into the sunlight.

https://www.krakenrf.com

Home | KrakenRF

KrakenRF

@pjf I'm pretty sure it's all alignment with laylines.

Stoneface Vimes Jul 9

@pjf or you could always use a wire coat hanger bent into a circle 😉😉

@pjf The antenna design (at 868MHz) for a little gadget I got to market made magic look tame. The AA battery cells were part of it for example.

Ben Thompson 🐕Jul 9

@pjf I had a similar epiphany when I was looking up how to let inside the silent whispers bouncing off the thick stone walls of our house, so they could mouth their sweet incantations into our smart meter. Two pieces of precisely bent purest metal joined by a length of cable you say? what is this dark wizardry?

Tim Serong Jul 5

@pjf AIUI it's a bit more fancy than just lowering the current draw. MPPTs are meant to dynamically adjust the load characteristics to get the most out of the solar panel at any given point in time. That sentence is the extent of my knowledge of how the technology actually works though -- there's a whole bunch of other stuff that I don't understand properly at https://en.wikipedia.org/wiki/Maximum_power_point_tracking ;-)

Maximum power point tracking - Wikipedia

Kit Bashir Jul 5

@pjf I have a shedload of stuff in stock and have recently (last munf) evaluated a bazillion ways to do this. For your sitch you don’t really “need” mppt as your charger will limit current. happy to send regulators (or further advice) gratis if it turns out you need them.

Paul Fenwick Jul 5

@Unixbigot : But it will work better if I have a MPPT module?

My understanding is the lipo chargers will try to use constant current up to a point, but if the panel is small or underperforming (I expect mine is both), then trying to draw that much current will tank the voltage, leaving it insufficient to charge the cell.

If my panel was large and good, I wouldn't expect any issues; the cell's own protection circuit can handle it.

Am I understanding correctly?

Kit Bashir Jul 5

@pjf yeah you’re spot on. your mcu board probably has a tp4054 charger chip, there’s a resistor that sets the max current limit (typically 200-500ma). In marginal sun *coughvictoriawintercough* that practically means you’ll only charge if the insolation is good enough. with a smarter charger (mppt and/or boost) you’ll get some energy as long as there’s sunlight. Here in brissy i’ve always been content with a bare panel.

neoluddite Jul 5

@pjf go for a walk outside, see if you can find any vapes?

Paul Armstrong Jul 5

@neoluddite @pjf It is shocking to me that there are disposable vapes. That's a lot of electronics etc to be disposable. :-(

@psa @neoluddite @pjf a friend collects the disposable vapes to harvest batteries. Amazing how many of them have charging circuits, but no exposed power socket.

Actually, did, or least not for much longer. They were banned in NZ last month.

Paul Armstrong Jul 5

@puck @neoluddite @pjf

In a bit of better news, the UK also recently banned them.

@psa @neoluddite @pjf Excellent! Timely given this article that confirms various concerns. https://www.acs.org/pressroom/presspacs/2025/june/metals-found-in-disposable-e-cigarette-vapor-could-pose-health-risks.html

Metals found in disposable e-cigarette vapor could pose health risks - American Chemical Society

Researchers report that some disposable vapes released higher amounts of metals and metalloids than older refillable e-cigarettes and traditional cigarettes.

American Chemical Society

Paul Fenwick Jul 5

@neoluddite : omg, this is brilliant!

Mike [SEC=OFFICIAL]Jul 4

@pjf I should jam mine back together and see if I can ping you!

Paul Fenwick Jul 4

@mike : Ooh, good idea! It'll be easy to spot my node name if you can.

Mike [SEC=OFFICIAL]Jul 4

@pjf mine *may* be online but I haven't looked at it for a while because there was a bug that kept resetting the node name. I'll dust off and update it and I'm pretty sure it'll have "Chinwag" in there somewhere.

John Cortexiphan Jul 4

@pjf that should be plenty of antenna. How far do you need it to work? I went up a hill once and got 20km on a bit of rough cut 1/4 wavelength wire. Lora is magical

Paul Fenwick Jul 4

@yakmoose : It *is* magical, but I'm in a built up area, so while I can see a node or two, it's not reliable, and most of the mesh isn't visible. I'm sure a better location would do waaaay better, but I don't have easy access to one.

Plus antennas are cheap.

Daniel Carosone Jul 3

@pjf there was a major vuln to do with cert issuance, and something in the update about blocking old certs. I don't recall details, but worth looking into

Paul Fenwick Jul 3

@uep : Already past that! Upgrading the node firmware was the first thing I did! 🎉

Incident Creator ❎Jun 21

@pjf
Following the cellphone ban, kids around here have developed an interest.

Paul Armstrong Jun 21

@pjf Is there much of a network around Melbourne?

Paul Fenwick Jun 21

@psa : Somewhat? You can see nodes on the map at https://meshmap.net/ , but that's only going to be a subset of them all. (Not all nodes report position, not all position reporting nodes agree to be mapped, and not all nodes are necessarily within range of a mapping node.)

Certainly the higher you get your antenna, the better your connection will be.

MeshMap - Meshtastic Node Map

A nearly live map of Meshtastic nodes seen by the official Meshtastic MQTT server

Paul Fenwick Jun 21

@psa : https://meshtastic.au/ also helped with setting things up.

@pjf you're sendin' bits and receivin' bits and the rest is just detail!

cafuego 🔭🤦🏼‍♂️Jun 18

@pjf There is a free antenna to be had in Goulburn.

Paul Fenwick Jun 18

@cafuego : lol! I think that one might be in excess to my needs!

Incident Creator ❎Jun 18

@pjf
Going to go down that rabbit hole with Young Grasshopper. Tomorrow's lesson is to make two Arduinos communicate over a wire. Probably another time we'll replace the wire with a 433MHz link, then move on to hooking up LoRa. Lessons move around semi-randomly though, so who knows where we'll actually end up!

Simon Cozens Jun 18

@pjf Heh. I remember getting into LoRa back in 2017 when my town in Australia set up a public network (they put repeaters on all the public buildings, radio masts, etc.). Very handy for controlling gates, pumps, temperature sensors outside of Bluetooth/ZigBee range.