Guerilla Mesh Nodes

In my view mesh communications are a vital and core part of remaining free as the United States slips further and further into fascism. While the internet continues to be beaten relentlessly by politicians from across the political spectrum with bills that limit freedom and anonymity, I fear a day may be coming where it is simply unusable as a secure method of communication.

Furthermore mesh networking supports community building through the strengthening of our ties and bonds with our neighbors as we make a united effort to connect to one another and connect those without the means to contribute directly.

Project Goals

I live in Rochester, NY so the node has to have some serious battery capacity in order to defeat the long stints of rain and snow we're subject to on a regular basis. Additionally the node will be in an extremely public place so it has to be discreet and blend in with the existing infrastructure. Finally, due to it's public positioning, it will need to be absolutely low maintenance or maintenance free and must provide it's own power.

[image] rochester weather

The Base Unit

This Solar Node Base Unit sports an 8W panel with 5V output. It's made from ABS and claims to be suitable for outdoor use. It also features a complete charge controller and a bank with space for four flat top 18650 cells. The outside has a physical waterproof power switch and windows to view the battery charge indicator and charge LEDs. The kit includes an antenna which I opted to use. It felt sturdy and was quite a bit longer than anything else I had laying around. I don't have a VNA to test with but if I encounter issues I'll update this post later. While the kit comes with mounting hardware it's very sad and thin feeling plastic and isn't the appropriate type of mount for the target which is going to require something a bit more robust.

[image] rear cover opened [image] the node

The Radio

The radio is a WisBlock Meshtastic Starter Kit. There are a lot of variants of this kit. The main radio here is the RAK4631 which is extremely power efficient and all the rage right now. I chose the RAK19003 base board with no additional modules to keep the cost down and the profile low though there is certainly room in the base unit for something larger. It could easily support a heltec for example, but since this is sitting in a solar node we aren't going to have access to, that's a lot of cost and hardware and little to no reason to have it. We don't need a screen, you won't be able to see it anyway. We don't need GPS, the node isn't ever going to move so we can take advantage of the static location feature in Meshtastic. The RAK19003 succeeds in providing exactly what we need here and nothing more for a very low price. The WisBlock starter kit includes a bunch of bits and pieces that might be handy down the road to stash for later such as low profile LoRa and Bluetooth antennas so stash that stuff for a future build or to give out to people who might need it down the road.

The Battery

For this first build I settled for some IMREN 18650 flat top cells off Amazon for my battery. The original listing is gone but I'm linking a similar one which includes all four cells you'll need. I'm in a rush to get this first guerilla node up and didn't have the time to wait but for subsequent nodes I'll purchase cells from a reputable 18650 dealer. I've had 18650BatteryStore recommended to me in the past. If you're trying to decide on a cell for this I would go with capacity over output power since our project here is going to sip near nothing from this battery at a leisurely pace.

Assembly

Remove the six screws from the rear cover of the base unit and set them aside. Find the included o-ring and fit it into the perimeter of the shell where the rear cover makes contact to keep moisture out. Peel the paper adhesive covering and press mount your radio into position. Find the Bluetooth antenna included with your radio, peel the adhesive covering and mount it to the interior wall. Connect your LoRa and Bluetooth antennas to the radio via the U.FL connectors. The connections are clearly labeled on the radio, just press until they snap into place. Next find the lead from the charge controller and plug it into the small white connector on the radio. In my base unit the charge controller polarization was correct and the connector matched the radio so it was hassle free. Once that's done insert your four 18650 cells into the bank making sure they're oriented correctly. Finally replace the rear cover, replace the screws and you're done. Flip the power switch and you've got a working solar powered Meshtastic node.

[image] node internals

Software

I'm not covering software in depth this guide but may come back to it later in a future post. There are so many resources out there on how to flash up-to-date firmware and configure your node. The official Meshtastic website is an excellent source and a great place to get started.

As far as the absolute basics I'll be running this node as a router after considering the vast amount of coverage it will be supplying for it's target location. Remote administration is configured with Bluetooth OFF and Managed Mode ON to prevent malicious access. This node will also be running power-saver mode since it won't be connected to directly for communication purposes and that will substantially cut down on it's power consumption overall.

[image] estimated node coverage

The Mount System

I underestimated the mounting situation. The base unit is really not equipped to be pole mounted so I had to get creative but I'm happy with how things ended up. I tapped into my videography roots and put together a solid kit that gets the job done in a dependable way. The ball head mount will be the first piece we're adding to the base unit. The base unit sports a ¼” mount on the rear which is going to be our mount point for this build. It is far from the strongest ¼” mount so do not over torque the ball head mount. You want it just tight, and then leave it be. Since this is intended to be permanent I secured mine with some clear two part epoxy to strengthen the hold after the fact. Next we'll attach the ¼” to 3/8” adapter. The ¼” end goes to the ball head mount and the 3/8” end very conveniently screws tightly into the sign mounting bracket. I'd throw a 3/8” locking nut on the back if I were you but I didn't have any at the shop so I hit that with some two part epoxy as well just to lock everything in place. With that done all that's left is the op.

¼” – 3/8” Adapters ¼” Ball Head Mount Two Part Epoxy Sign Mounting Brackets 3/8” Locking Nut Pole Banding

[image] a shitty picture of the mount

Deployment

Deployment is simple if you've planned ahead. Have a low profile backpack set aside with everything you'll need to deploy. The bag should be packed with:

Cut three lengths of banding in advance for 14”, 8” and 6” diameters. This allows you to change targets on the fly and ensures you'll have a banding prepared for whatever diameter pole you're interfacing with. MOUNT AND TEST YOUR WORM DRIVE IN ADVANCE. The last thing you want to be doing on a street corner is fiddling with getting the drive installed and secured or dealing with jams. Terminate one end with the drive and make sure the opposite end of the banding feeds through the drive smoothly. If you are experiencing jams cut a small amount of the banding off to try to get a smoother edge and try again. Once you have your three pre-cut lengths with drives mounted and a smooth action you're ready to move on.

I think a night-op has the highest chance of success without interference, though if you have balls of steel you could attempt this in broad daylight. Most people aren't going to bat an eye at what you're doing and if you run into a cop you're fucked either way and the op is over.

Park at a closed business about a block from the site and unload your gear. Don't forget to put on your hi-vis vest. Your gut is going to tell you to be as dark and discreet as possible but your gut is wrong. This is a hide in plain sight situation. A dark hooded figure fucking with public infrastructure is going to stand out like a sore thumb to anyone who happens to drive by while you're executing.

Walk from the parking location to the site on foot and remove the supplies from the bag. First grab the banding and check all three pre-cut lengths for fit. Once one is selected we thread the banding through our mounting bracket and place the node against the pole. In most cases with few exceptions the node should be south facing as to gather as much of the daytime sun as possible.

Holding the node in the desired location you then thread the banding into the worm drive on the north side of the pole and use the power drill to quickly secure it. If your worm drive is jamming after your dry runs, you have extras and they can be swapped out easily by hand or with a small pair of pliers. Mounting the node while keeping it in place can be tricky to do alone so if you have a dumb friend you can talk into giving you a hand that's a plus and will keep your op time short. Finally, use your tin snips to snip off any extra banding, pack, lose the hi-vis vest in the bag and bail out.

From the time you arrive at the target site to the time you are walking away should be about 60 – 120 seconds, less if you're fast, practiced or have a friend.

If we work together we can create a mesh network that will support our efforts to resist fascism and tyranny in America, strengthen our bonds we share with our neighbors and help create the networks that will keep communication free, open and resistant to censorship for years to come. Be safe out there, love each other, go fast and don't get caught.

~Six