Nebra IP67 Weatherproof case build

[kc1awv]

I thought a writeup and questions should be handled here on my RAK build for Kaizen, the local area transport node and reference RetiBBS system I put together.

The case itself is a Nebra IP67 Weatherproof Enclosure that was apparently originally designed as some sort of IoT thing for Raspberry Pis and a LoRa gateway hat. I originally purchased it long ago from DigiKey to see if I could get Reticulum to work with that hardware, but the project got put off for other things. That was, until I saw the RAK 4631 get RNode support.

I designed a plate that can fit inside the Nebra case that holds a Pi and a RAK 19007 with a RAK 4631. I suppose I could have designed it for a RAK 19003, but I didn't have one on hand.

The case takes an M20 cable gland to pass through Ethernet, I found this on Amazon which fits the case nicely. Instead of putting a PoE HAT on the Pi, which increases the height of the device and may cause the lid to not close properly, I went with a PoE splitter that can provide 5v 4A of power, and a right-angle USB C plug adapter I had on hand. A pair of U.FL to N pigtails then pass through the antenna connections for the RAK 4631 to a couple proper antennas (2.4GHz and 900MHz) outside. The RAK board is connected to the Pi using a USB A to USB C cable.

The whole thing is still indoors for now, since it is winter and I can't (safely) get on the roof to install it on a pole just yet.

I did use a Pi 5 on this build, with an Argon40 low-profile heatsink and fan. Even indoors at 20C with the case closed, the Pi doesn't exceed 55C. I bet it would run cooler if I had it outside, where the ambient temperature is between -5C and 0C currently.

If you want to build this like I did, this is what you'll need:

• Nebra IP67 Weatherproof Enclosure
• M20 CAT 6 Ethernet Cable Gland
• PoE Splitter (5V/4A)
• U.FL to N bulkhead pigtails
• M3 Standoffs
• M3 SHCS
• M2.5 Standoffs, hex nuts, and screws
• Right angle USB C plug adapter
• Right angle USB A to USB C cables
• LoRa antenna with N connector (Make sure to choose one for your frequency band)
• Optional: 2.4GHz antenna for bluetooth or wifi
  • I added it because I had it, I'm not using BT or WiFi on either the Pi or the RAK. If you don't add this antenna, at least use the BT FFC antenna to the RAK just in case. Who knows if it'll burn out or not without it.
• Raspberry Pi (3, 4, or 5 are fine)
• SD Card (Your choice of size)
• RAK 19007
• RAK 4631
• 3D Printed plate

Assembly:

• Print plate face down
• Install short M2.5 standoffs and hex nuts to the plate (8 total, nuts are held captive by recesses in the plate)
• Install M3 standoffs in the case, matching mounting holes in the plate (8 total)
  • Standoffs should be tall enough to have the plate sit flush with the lip of the case, or enough to have room to fit the PoE splitter underneath the plate
  • I think I used M3x12 standoffs
• Install U.FL - N bulkhead pigtails
• Install M20 CAT 6 Ethernet cable gland
• Install PoE Ethernet / 5v 4A splitter, secure with self adhesive Velcro tape
• Install plate using M3 screws (I used M3x8 SHCS)
• Install Pi and RAK using M2.5 screws
• Route cables
• Install antennas
• Flash and install SD card
• Connect Ethernet cable from PoE switch
• Profit

[markqvist]

Oh, this is very nice man! Thanks a lot for producing the writeup and sharing all the resources!