This repository contains different housing designs intended to provide some protection for a SnapperGPS PCB V1.0.0, a battery, and an antenna or a SnapperGPS receiver V2.0.0 during testing and potentially during deployments.
Most designs (but not all) are intended to be either 3D-printed or CNC-milled. If you want to use any of these designs for a long-term deployment, we advise you to carefully consider whether the material is suitable for the deployment environment. It might be possible to make the housings more suitable by applying a finish to the outer surface.
Other housing options for packaging a SnapperGPS PCB for a deployment include:
- Heat-shrink tubing (light-weight, low-cost, and waterproof), and
- Vacuum packing (light-weight, low-cost, and waterproof).
- A commercial box.
While the 3D-printed housings are designed for the SnapperGPS receiver V1.0.0, these additional opetions also apply to the SnapperGPS receiver V2.0.0.
To avoid creating an electrical short when using a V1.0.0 receiver, we suggest to ensure that none of the components in the enclosure (PCB, battery, antenna) directly touches another one. For example, this can be done by putting some tape on the components if they would otherwise make direct contact.
- Waterproof sea turtle cases for V2.0.0
- Tray (APAM1368YB13V3.0)
- Tray (Echo 27 V2)
- Thin box
- Thick box
- Box with cut-outs
- Turtle case
- Waterproof case without threads
- Heat-shrink tubing
- Vacuum packing
- Heat seal bag
- Commercial box
- Acknowledgements
Unlike most housings below, these cases are intended for the SnapperGPS PCB 2.0.0. If produced with a CNC machine, they can be waterproof in more than 100 m depth. Each design consists of a top and a bottom piece. The top piece is to be machined out of POM while to bottom piece can be made out of transparent polycarbonate, POM, or aluminium. There is a smaller and a bigger version, which provide the same interior space, but differ in their outer appeareance. In addition, the big version can go with a thinner (5 mm) or thicker (7 mm) bottom plate. Both versions require countersunk M4 screws, 10 mm length such as these from RS-Online for the thin bottom pieces or 12 mm length for the thick bottom piece. You will also need a 50 mm (inner diameter) x 2 mm (cross-section) o-ring such as these from Polymax.
The tray holds a SnapperGPS PCB, a flat battery, and an APAM1368YB13V3.0 active GNSS antenna in place.
The tray holds a SnapperGPS PCB, a flat battery, and an Echo 27 V2 active GNSS antenna in place.
The box holds a SnapperGPS PCB, a battery, and an active GNSS antenna, e.g., an Echo 27 or an APAM1368YB13V3.0, in place and can be closed with a lid.
The same as the thin box, but with twice the wall thickness.
The same as the thin box, but with two cut-outs to attach a USB cable and to monitor the status LED without opening the box.
This is a design for a waterproof enclosure (if machined out of waterproof materials). It requires 14 countersunk 10 mm M4 screws, such as these from RS-Online. You will also need a 59 mm (inner diameter) x 2mm (cross-section) o-ring such as this one from Polymax.
You can design your own inserts based on the antenna and battery you are using. Alternatively, you can make a cut-out from a thick piece of packaging foam. Cut it slightly oversized so the components sit snugly when the enclosure is closed. Make sure that the tag cannot jiggle around in the tag.
If you machine any piece of the housing out of metal, ensure that none of the electrical components can come in touch with it to avoid shorts.
A version machined out of polyoxymethylene (for the top) and aluminium (for the baseplate) has been successfully deployed on nesting loggerhead sea turtles.
You can find more information on deploying SnapperGPS on (sea) turtles in this dicussion.
This design is a smaller and simpler version of the turtle tag. Instead of using machined threads, this design uses nuts to seal the case.
For this version, I had some 15 mm M3 Phillips Pan Head screws and nuts left over from this set. But if you have access to Fusion, you can also edit the .f3d file to fit other types of screws. I recommend getting nuts with nyloc inserts. They won't come undone as easily.
You will also need an o-ring with 2 mm cross-section and 48 mm internal diameter. I used this one from Polymax.
As before, I recommend cutting an oversized piece of packaging foam to hold the components in place. Make sure that the electronic components cannot jiggle around or short out by touching each other. I used insulation tape and double-sided tape to glue all the parts together. This makes the components easy to handle and prevents accidental shorts as well as unnecessary stress on the antenna and battery connector.
This repo contains a version with loop holes (pictured) and one without. The photos show a model 3D-printed out of PLA. As such it won't dive-proof but it's still a very sturdy, weather-proof case that you can cable tie to your backpack/bike/boat/flying car.
For a waterproof case, we recommend CNC machining the top out of polyoxymethylene (POM) and the plate out of aluminium (beware of shorting out the electronics).
Heat-shrink tubing is a light-weight, low-cost, and waterproof way to enclose a SnapperGPS receiver for deployments where no sturdy housing is required. For this, you need heat-shrink tubing that is wide enough to fit a SnapperGPS receiver. (A SnapperGPS receiver has a width of 27.3 mm and a length of 32 mm.) Cut a tube that is about 2 cm longer than a SnapperGPS receiver and place a receiver in the tube. Next, heat the tube, e.g., using a hot air gun, a lighter, or an oven, until the tube has shrunk and wrapped around the receiver. Finally, use hot pliers, a curling iron, or something similar to seal both ends of the tube.
Vacuum packing is a light-weight, low-cost, and waterproof way to enclose a SnapperGPS receiver for deployments where no sturdy housing is required. For this, you need vacuum sealer machine / vacuum packing machine. It can be a low-cost machine like one of those that can be used for food sealing at home.
Heat seal bags are another light-weight and low-cost way to package a SnapperGPS receiver where no sturdy housing is required and packaging size is not a tigh constraint. For example, these ones have been used in the past and could also be used for vacuum sealing.
Consider adding some silica gel bags inside.
You can also buy an off-the-shelf enclosure that fits a SnapperGPS receiver and its peripherals, for example, a plastic box like this one from the Hammond 1551 series for a SnapperGPS receiver V1.0.0 or this one from the same series for a SnapperGPS receiver V2.0.0. Always check that protection against water, dust, and mechanical force are aligned with your deployment conditions. For this, you might want to familiarise yourself with IP codes.
SnapperGPS is developed by Jonas Beuchert, Amanda Matthes, and Alex Rogers in the Department of Computer Science of the University of Oxford.
Jonas Beuchert and Amanda Matthes are funded by the EPSRC Centre for Doctoral Training in Autonomous Intelligent Machines and Systems (DFT00350-DF03.01, DFT00350-DF03.05) and develop SnapperGPS as part of their doctoral studies. The implementation of SnapperGPS was co-funded by an EPSRC IAA Technology Fund (D4D00010-BL14).