Meshtastic Solar Easter Egg 🐇

Looking for a fun, eye-catching way to build a solar-powered node that’s lightweight, weather-hardy, and tough enough to handle life’s little surprises—like curious kids, rogue squirrels, or a gust of spring wind? Meet the Solar Egg Node, a fully self contained device tucked inside a jumbo 10-inch clear plastic Easter egg!

Its round, self-righting shape means you don’t have to worry about it tipping over, whether it’s sitting on your patio, tucked into the corner of a garden, or part of a techy scavenger hunt. This design is especially great for temporary setups where permanence isn’t possible or preferred.

This cheerful build is perfect for anyone who loves clean energy, colorful enclosures, and experimenting with off-grid communication or sensor projects—whether you're sharing data across your backyard or giving your next springtime STEM project an egg-stra dose of sunshine!

Let’s crack this egg open and see what’s inside!

Unlike my previous Solar Buoy project where space was at a premium, this one has tons of room for the Easter Bunny to "hop" across town!

Feel free to substitute whatever supplies you already have. I used a couple of small wire nuts to connect my solar panel instead of soldering everything. You might find something cheaper to use as a counterweight... My first prototype used a couple of dead C-cell batteries. Personally I think the baseball bat weight looks great for a finished product. UV resin worked perfectly to fasten my weight to the base and for attaching the solar panel I went with hot glue because it can be removed without damage to access the RAK board.

Due to the uncertainty of tariffs on shipments from China for AliExpress, I've attempted to find links that will ship from the US whenever possible. #affiliatelinks to help pay for more supplies. If you like this design, please consider purchasing my STL file on Cults3D.

Supplies:

1. Clear Plastic 10-inch Jumbo Easter Egg: Amazon | eBay | AliExpress
2. RAK19003 Meshtastic WisBlock Starter Kit: Rokland | (Sold out on Amazon)
3. 915MHz Antenna (no longer than 17cm to fit inside the egg): Amazon | AliExpress
4. Solar Powered Water Fountain, 16cm Diameter: Amazon | eBay | AliExpress
5. 3000mAh Flat Li-Po Battery Pack: Amazon
6. Custom 3D printed parts to mount the RAK board and antenna: Cults3D (STL download for purchase)
7. A baseball bat weight... the cheapest, heaviest thing on Amazon! Amazon
8. Flexible UV Resin: Amazon
9. UV light to cure resin: Flashlight or Curing Light
10. 2mm female JST connector (plugs into the RAK battery socket): Amazon | Rokland
11. 1.25mm male JST connector (for the Li-Po battery to plug into): Amazon
12. 1.5mm female JST connector (for the solar panel to plug into the RAK solar input): Amazon | Rokland
13. 1.6mm shrink wrap tubing for 22awg wires: Amazon
14. "Alien tape" or similar outdoor rated double-sided tape: Amazon
15. Clear "self-fusing" silicone repair tape: Amazon | eBay

Tools:

1. Wire cutter and stripper
2. Heat gun or hot hair dryer: Amazon
3. Soldering iron and solder (or four small gauge wire nuts)
4. Hot glue gun and glue stick

1) The water fountain comes with a small pump wired to the solar panel's power brick. Simply twist and pull the pump to remove it from the panel.

2) Cut the pump wire about half-way from the panel and strip about 3/8 inch of insulation from each of the solar panel's output wires. Save the pump for a future project :-)

3) Attach a 1.5mm female JST connector to the solar panel wires. I used some small wire nuts, but soldering is great too. This will plug into the RAK's solar input.

CHECK THE POLARITY! The solar input's red (positive) wire needs to face the center of the RAK board when plugged in. If you need to reverse the polarity, use a small screwdriver to pry up the plastic tabs on the plug and swap the pins. There is no standard polarity on JST plugs, so you need to check!

1) Mount your BLE antenna to the solar panel's plastic power block using the double sided adhesive that comes on the stock BLE antenna in the WisBlock starter kit.

2) Mount the SMA connector that comes in the WisBlock kit into the center hole of the solar panel. The barrel of the SMA connector is smaller than the center hole of this solar panel, but you can 3D print an adapter like I did, or glue it with electronics-safe adhesive. Use a lock washer and nut to secure the connector to the adapter.

The MakerFocus brand Li-Po battery pack I'm using came with a 1.25mm JST plug. That means in this project we have three sizes of JST plug to contend with. 2mm for the RAK battery input, 1.5mm for the RAK solar input, and 1.25mm for the Li-Po battery output. You could cut the 1.25mm plug off of the battery and replace it with a 2mm plug. However, since the connectors I purchased came with both male and female connectors, I chose to make a small adapter for the battery.

1) Cut the wires of both a 1.25mm male connector (for the battery to plug into) and a 2mm female connector (to plug into the RAK battery input) to about 1.5 inches long.

2) Cut two pieces of small shrink wrap tubing about 1.5 inches long.

3) Slide the tubing pieces onto the wires of one connector.

CHECK THE POLARITY! Make sure the red wire on the battery input will be facing the center of the RAK board when plugged in. If not, pry the plastic tabs up on the plug and reverse the pins.

4) Solder the connector wires together. Red-to-red, black-to-black.

5) Slide the shrink wrap tubes over both solder joints and shrink them with a heat gun or hot hair dryer.

1) Attach the RAK board to your 3D printed bracket using three screws from the WisBlock starter kit.

2) Use a piece of Alien Tape or other heavy-duty double-sided tape to attach the bracket to the underside of the solar panel.

3) Use another piece of Alien Tape to attach the battery to the underside of the solar panel.

4) Screw the antenna onto your SMA jack before plugging in the battery.

5) Plug the solar panel connector into the RAK solar input.

6) Plug the battery into the RAK battery input.

At this point the Meshtastic node itself is fully functional, albeit completely impractical, not waterproof, and goofy looking. Let's move on to the star of the show, the giant plastic egg!

There is advice online that waterproof enclosures may require a bottom vent to prevent and/or drain condensation that forms inside the enclosure. These eggs will never be air-tight and mine came with a small safety hole in both the top and bottom halves. I believe these are to prevent the eggs from becoming a suffocation hazard for children or pets. Since I don't want rain dripping in through the top, I decided to seal the upper hole and leave the bottom hole open as a condensation vent.

1) Use piece of Scotch tape to seal the upper vent hole from the inside of the egg.

2) Place a drop of UV resin in the outside of the hole and cure it with a UV flashlight

3) Remove the Scotch tape and place a drop of UV resin on the inside of the hole. Again cure it with a UV flashlight.

This part is important. You need your weight to be very securely fastened to the inside bottom of the plastic egg shell. If it were to come loose while your egg was being tossed around it could cause internal damage.

1) Place a baseball bat weight (12oz is plenty!) inside the bottom center of the egg shell.

2) Use UV resin or other strong electronics-safe adhesive to permanently fasten the weight to the shell.

Interestingly with this design the radio, battery, and solar panel can operate completely independently of the outer shell, yet need to be fastened securely to ensure the panel and antenna will always point upright. Additionally you may need to access the USB port on the RAK board to upgrade firmware or recharge the battery. With that in mind, I used some old fashioned hot glue to secure the panel in place! To remove the panel in the future I can melt the glue with heat and replace it without damage.

1) Place the solar panel assembly into the bottom half of the egg shell and level it so the antenna is pointing straight up. It should come to rest couple of inches above the bottom of the shell.

2) Use a hot glue to attach the top edge of the solar panel to the inside of the egg shell at multiple spots around the perimeter. Wait for it to cool.

Slide the upper half of the egg shell onto the lower half. It should fit snugly but it can easily pop off when you squeeze the shell or lift it with the handle since you now have something much heavier than Easter candy and fake grass in the bottom of your egg. Fortunately at the joint the upper half of the shell overlaps the lower, so the joint itself should shed rain effectively and prevent water intrusion. The cheapest way to keep the halves from separating might be to tape the joint with some heavy duty clear packing tape. To make the finished product look nicer I found this clear self-fusing silicone repair tape that does the job.

1) Unroll a few inches of self-fusing silicone repair tape and hold it over the joint between the halves of your egg, Be carefull not to touch the tape to itself because it will stick together almost instantly and is difficult to peel apart.

2) Carefully stretch the tape tightly around the perimeter of the joint taking care that there are no wrinkles. The tape will barely stick to the plastic egg itself, but the stretching tension should help hold it in place. Carefully peel off the outer protective wrap on the silicone tape as you go.

3) Cut the silicone tape to overlap itself by a couple of inches after going all the way around the egg. Keep tension on the tape and press it into itself for a few seconds. The silicone will quickly adhere to itself and form a solid band around the perimeter of the joint.

Remember those old fashioned weeble-wobble toys? This can do that and so much more!

Thanks for reading my Instructable. If you decide to build it, I'd love to see photos of where you decide to hide your eggs! Suggestions for improvements are always welcome as well.

Happy Easter!