SEEEDpod EDC

Description

SEEEDpod EDC is the smallest possible footprint for the Seeed Studios nRF52840 kit. It’s slim enough to fit in your pocket, and can be post processed to achieve up to IP67 waterproof.

It houses up to an 18650 battery. There is enough headroom for a slim BMS. Shorter and or slimmer batteries can be used if a larger BMS is required.

It may be assembled with glue and or screws. Both should be used to achieve best results, but one or the other may prove adequate for your application. Glue may be used in situations where hardware isn’t available, and hardware may be used exclusively if the material doesn’t glue well (e.g. PETG).

Hardware needed:

• Two M2x20 socket cap screws
• Five M2x30 socket cap screws
• One 10mm OD 7mm ID O-ring

To waterproof:

Prime with a heavy coat of filler primer (be sure to mask the USB-C port), then finish with top coat of your choice. It may be helpful to smooth the O-ring glands with fine emery cloth prior to priming, and softer O-rings like silicone will make a better seal on an irregular surface. The smoother the surface and the softer the O-ring, the better the seal will be. Note that failing to glue the housing together will result in seams flexing, which may break the seals formed by the paint, allowing water to infiltrate. For best results, the housing should be both glued and fastened, but glue alone can be sufficient depending on the glue, material, and application.

Materials:

ASA is probably the best all around material. It’s stable even at higher temperatures, it glues well, and it takes paint well. PETG is a tempting material because it’s also stable at higher temperatures, but it doesn’t glue or take paint as well, making it harder to weatherproof. HTPLA, especially fiber reinforced ones, will perform better than regular PLA, and they are easy to print and take glue and paint extremely well. Ultimately, material choice just boils down to the intended use. For most applications, regular PLA and super glue will be sufficient; just don’t leave it in your hot car (for your battery’s sake as much as for the housing). Also note that color will have a MASSIVE impact on how much it will be affected by direct sun, with lighter colors being ideal. If regular PLA is used, it’s advisable to skip the O-ring and not overtighten the cap, as the creep associated with PLA will eventually cause the threads to fail if they are left under load. Carbon fiber should be avoided, at least for the antenna housing, as it’s electrically conductive and may interfere with radio signal.