Solar Meshtastic Node

A Station G2 Meshtastic node on a pole in the backyard, running on a 12-volt solar battery, with its battery voltage reported over the mesh

White fiberglass antenna on a metal pole beside a patio cover, with a small tan weatherproof box just below it — The G2 in its weatherproof box at the top of the pole, right under the antenna, about 12–15 feet up (click for the full photo)

Meshtastic turns small, inexpensive LoRa radios into an off-grid text messaging network. Every node repeats what it hears, so messages hop from radio to radio across town with no cell towers or internet. The more well-placed nodes there are, the farther the mesh reaches, so I put up a node of my own.

It's a Station G2 from B&Q Consulting, a Meshtastic radio with a built-in amplifier that puts out much more power than a typical handheld node. It's set to the Client Base role, so it relays traffic for the mesh. It sits in a 3D-printed holder of my own design inside a weatherproof box at the top of a pole, right below an 8 dBi fiberglass antenna. Power comes from a 12-volt LiFePO4 battery kept charged by a 100-watt solar panel and an MPPT charge controller, so it needs no wires to the house. The same battery also runs my LoRa APRS iGate.

The G2 is on my home Wi-Fi. A small server in the house reads what the G2 hears, along with its own readings, and passes it all to the Mesh page every 5 minutes. That's where you can see the G2's battery, how busy the channel is, and the nodes it hears.

Keeping an eye on the battery

The Station G2 is designed to run on outside power, so it has no battery gauge. Its maker explained why: it accepts a wide range of input voltages, so it can't know what a full battery looks like. Since the node was going up where I can't easily check on it, I wanted to watch the battery from a distance anyway.

The answer, from the Station G2 wiki, is an INA219 voltage and current sensor plugged into the G2's QWIIC connector. I built a new power cable, with Anderson Powerpole connectors, that puts the sensor right at the G2's power connector. Meshtastic reads the sensor on its own and every 30 minutes sends the voltage reaching the G2, which follows the battery, and the current the G2 draws. They go out as environment metrics, so they show up in the Meshtastic app and on this site's Mesh page.

The build

Parts on a workbench: an open gray weatherproof box, the Station G2, a power lead, a coax jumper, a mounting plate, a pole bracket and a white fiberglass antenna — The parts: enclosure, Station G2, cables, pole bracket and the 8 dBi antenna

A 3D printer with a freshly printed white holder on its build plate — 3D printing the holder I designed for the G2

The Station G2 mounted in the open gray box, with a short coax jumper looping up to the antenna connector — The G2 in its holder inside the box, with a short jumper up to the antenna

The closed gray box and antenna on a short pole in a garage workshop — Assembled on a test pole in the garage

A 100-watt solar panel lying on a patio, propped on two strips of wood — The 100-watt panel during testing

The 12-volt battery and the small MPPT charge controller, its lights on, wired together on a patio with the solar panel's cables — Testing the battery and MPPT charge controller before the move to the pole

Adding the battery sensor

A small red INA219 sensor board with red and black power wires, and a short QWIIC cable — The INA219 voltage and current sensor and its QWIIC cable

A finished power cable in black split loom with the red sensor board spliced in and connectors on each end — The finished power cable with the sensor built in

A cluttered workbench with the Station G2, wire, a soldering setup, crimpers and a hand-drawn wiring sketch — Soldering and crimping the new power cable, working from a quick sketch

The G2 in its box on the bench, wired through the new cable to a 12.8-volt 6 Ah LiFePO4 battery — Bench test with the sensor installed, on the 12.8-volt 6 Ah LiFePO4 battery

Parts

Station G2 (B&Q Consulting) Meshtastic node, role Client Base
8 dBi 915 MHz fiberglass LoRa antenna, omnidirectional, on a pole about 12–15 feet above the ground
IP65 ABS weatherproof enclosure, about 8 × 4 × 2.7 inches, with a hinged lid
3D-printed holder of my own design for the G2 inside the enclosure
INA219 voltage and current sensor on the G2's QWIIC connector, reporting as environment metrics
12.8 V 6 Ah LiFePO4 battery (76.8 Wh), shared with the LoRa APRS iGate
PolyEnergy 10-amp MPPT solar charge controller
100-watt monocrystalline solar panel
Anderson Powerpole connectors on the power cables

Links

Live: the G2 and the nodes it hears On the About page Meshtastic Station G2 wiki Meshtastic telemetry settings

Credits

Meshtastic is free and open source. Thanks to B&Q Consulting (Unit Engineering), the makers of the Station G2, for explaining why the G2 has no battery gauge and pointing me to the INA219 sensor.