project 2025-09-22 5 min read

Super Cheap Meshtastic Solar Node

First things first: I’m standing on the shoulders of giants with this. It wasn’t my idea, I’m just documenting my build following the excellent guide from BuffaLoRa.

Solar-powered Meshtastic node hanging on house siding for testing

Hanging on the siding while I test charging and stability

Flash your radio and set it up

Go ahead and flash your radio before you really dive in. (Make sure you leave the ~~crappy little~~ antenna it comes with connected so you don’t fry the radio.)

Xiao nRF52840 with Wio SX1262 module, very small in hand for scale

I went ahead and configured everything about my node at this step so I could move quickly to testing and hanging it up once the build was done.

Let’s build this thing…

Tip: Install the brackets right away so you don’t forget like I did on my first build.

Solar gutter light disassembled, ready to begin the build

Make a note of which end is positive — I know the negative end has a spring, etc, but belt and suspenders. Then take the battery out and set it aside.

Battery compartment showing positive and negative terminals

If you don’t plan on using the lights, clip one of the leads going to them. I confirmed that the battery doesn’t charge if you don’t have the switch in the “ON” position, so if you don’t want lights draining the battery overnight, or just lights in a weird place around your house, go ahead and snip that now.

Snipping the lead going to the LED lights

Solder the power leads to the battery contacts. My leads were already tinned, so I was able to just sit them on there and give it a boop with the soldering iron and they sunk right in.

Power leads soldered to battery contacts

Separate the Xiao module from the Wio module.

Solder the connector to the battery leads of the Xiao module. This is teeny tiny, so if you have bad eyes and shaky hands like I do, take a deep breath and just try your best. On my first one, the tinned leads just stuck to the pads. On the second one, there was much wailing and gnashing of teeth, but I put a little solder on each pad and then was able to get the wires to stick. YMMV.

Xiao module separated from Wio module, showing tiny battery pads

Battery wires successfully soldered to Xiao module pads

Once you have the wires soldered to the Xiao, you can connect the pigtail to the Wio and put them back together.

Now it’s time to make a hole for your external antenna. I know that’s optional, but it’s what I did. I measured roughly to the middle, both ways. If your pigtails are long enough, you can put it on whichever end makes the most sense for you. (Note: It’s a little crowded on the end with the charge controller.) Use a 1/4" bit. (Probably double check that, but that’s what worked for me.)

Drilled hole on the outside of the housing for external antenna