Meshtastic or MeshCore DIY Solar Node using a Hampton Bay Solar Garden Light

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A classic DIY reference station for an outdoor solar node.

Existing designs for Meshtastic/MeshCore solar nodes involve using Harbor Breeze (Li-ion battery) solar garden lights. A RAK4630 or RAK4631 core with a RAK19007 or RAK19003 base board can also run using LiFePO4 batteries, a superior choice for outdoor nodes running in extreme weather due to their temperature stability. Additionally, they are generally safer and more environmentally friendly than Li-ion batteries. The design supports a compact N-Connector antenna such as the Alfa (aoa-915-5acm). But if you decide to go with an externally mounted antenna, the external SMA jack on the design will support that. My nodes running this configuration are located in the high desert, where temperatures are extreme. Total cost should run you around $65 to $75 USD depending on where you source your parts, and becomes very cost-effective if building two or more units since you'll have the parts.

Designed to be durable enough for a high-elevation router in harsh environments, it achieves an ideal angle for your solar panel for maximum power generation in North America and Europe. Most other solar nodes are have panels positioned at sub-optimal angles or risk loosening/tilting.

CHECK YOUR POLARITY! When wiring things up, remember that the JST PHR-2 connector is in reverse polarity (compared with most JST PHR-2 wiring). The JST connector should be soldered straight to the battery leads to supply the nominal 3.2V to the base board.

I recommend printing in PETG.

The installation instructions are based loosely on this article.

BUILD TIME

Approximately 45 minutes excluding print time.

MATERIALS NEEDED

• RAK4631 and base board kit (you'll need the MHF to SMA adapter in the kit). Cost: $35

• "120 Lumen Black LED Weather Resistant Outdoor Landscape Solar Spotlight with Color Changing and Adjustable Head" light from Home Depot, model # 72302-003-New. Cost: $13

• A compact N-Connector compatible antenna such as the Alfa (aoa-915-5acm) ($8 - $20).

• JST PHR-2 connector or similar to solder to battery leads: COST: < $1

• "Ahoaepy 2PCS SMA N Female Connector 4 Hole Flange Panel Chassis Mount Adapter, Low Loss N Female to SMA Female Panel Mount Adapter for CCTV, WiFi Radios, Antenna" product on Amazon. COST: $4 each

• 4 x M3 stainless steel screws that are 6mm to 8mm long (6mm being ideal), with accompanying nuts. COST: < $1

• 12" coax with SMA male ends: $10 or much less if you build it yourself. I recommend building cables using marine-grade shrink if possible. If not, waterproofing tips below.

• 4 x #8 1-1/4" exterior screws.

• Soldering iron and flux.

• Screw driver or drill or impact gun with a Phillips head bit for mounting.

• PETG filament.

• OPTIONAL: Outdoor silicone sealant, Temflex 2155, Super 33, Loctite 242 (blue).

BUILD AND INSTALLATION

1. Unscrew the six screws on the solar panel assembly. Open, being careful of existing wiring.

2. Locate the wiring coming from the LED portion of the light and unplug the PCB plug. Cut ONLY the wires going from the solar panel assembly down to the LED light. Discard the PCB plug.

3. Being careful not to lose the nut, unscrew the screw located between the solar panel assembly and the lower LED light assembly. Keep the screw and the nut handy - you'll need this for the mount.

4. Remove the cut wires leading from the solar panel assembly to the LED assembly. You may discard the wires and LED assembly.

5. Solder the JST PHR-2 to the battery leads (check polarity).

6. Drill a 1/4" hole on the battery side of the solar panel assembly. The antenna will be connected here. Think and measure first before you drill. See photo above for approximate location of the hole.

7. Install the antenna SMA to MHF converter in the hole you just made on the solar enclosure, optionally applying exterior (door/window) silicon sealant to the joint from the inside. The weep hole that comes standard with the enclosure will drain away excess moisture. Once complete, attach to the RAK core.

8. Install the RAK unit inside the solar panel assembly. Optionally print a small standoff board (example standoff print) before installing to avoid moisture accumulation on the board's components.

9. Close the solar panel assembly using the six screws from Step 1.

10. Connect the N Connector to SMA adapter to one end of the 12" SMA coaxial cable. and optionally waterproof this connection (see "waterproofing" below). Afterward, the mount the N Connector to SMA adapter to the mounting you printed, first by passing the free end of the coax through the mounting hole. You will need 4 x M3 screws that are 6mm to 8mm long to attach the adapter to the assembly. Optionally apply Loctite 242 to the screws where they will engage the nuts. This will prevent wind from potentially loosening the screws over time.

11. Mount the completed assembly to a post or 2x4 using 4 x #8 1-1/4" exterior screws. If you are mounting to a pole, you can use something like a 1-7/8 in. Galvanized Steel Wood Post Adapter depending on your pole diameter. Ideally, face the solar panel to the south if you live in North America or Europe.

12. Use the screw and nut from Step 3 and attach the completed solar enclosure to the mount assembly. I recommend Loctite 242 here as well.

13. Connect the other end of the 12" SMA coaxial cable to connect to the solar enclosure's SMA port. Optionally and carefully waterproof this connection (see "waterproofing" below). 

14. Grab a beer and appreciate your handiwork.

WATERPROOFING: To waterproof all connections, including the antenna, I recommend wrapping each joint first with Temflex 2155 and then Super 33 electrical tape. This is a trick used by hams, and can last 10 to 20 years depending on environmental conditions and the quality of the application.

CHANGELOG

[v3.0] - 2025-1-21

• Added N-Connector antenna attachment to the design. If the antenna attachment is not needed it can be removed with a suitable slicer (e.g., Prusa Slicer).

• Old designs still included, but "wedge" removed.

[v2.0] - 2025-12-28

• After some extreme 75+ MPH winds, I've added a "limiter" to the design to prevent the unit from tilting, plus a small wedge that can be used if you want to reduce play.

• Added HamptonBayNodeMount-WithLimiter.stl - This file contains the new limiter design. It will remove the ability to tilt the solar unit, but makes it impervious to winds.

• Kept HamptonBayNodeMount.stl - The old design with no limiter.

• Added HamptonBayRepeaterMount-Wedge (OPTIONAL) - A small wedge that can be used if you want to completely eliminate any play. The overall design is meant to accommodate a variety of antenna angles, but this can be used to completely "lock" the unit.

[v1.0] - 2025-12-22

Initial release

MAKER'S NOTE

If you need the design modified for any specific use case you have, particularly common use cases, let me know by leaving a comment! If you download and build this design, please rate it!