Raspberry Pi 4 Case WiFi and Bluetooth modification and the addition of POE without a HAT.
WiFi problems due to poor case design
The problem with after-market cases for Raspberry Pi’s is that the designers fail to take into consideration the on-board WiFi and Bluetooth antennas. In the image below you can make out the Bluetooth slot next to the board fixing screw and the triangular WiFi slot to the right of it. This case was modified to allow both antennas to propagate.
Image showing case cut-out to allow WiFi and Bluetooth antenna propagation on Raspberry Pi 4B
Typical cheap Chinese MMDVM case where the WiFi port is restricted by the poor design of case.
Many Radio Amateur enthusiasts build or buy MMDVM Hotspots which is a Raspberry Pi Zero W with a MMDVM modem HAT. These are notoriously difficult to connect to some Access Points because of the design of the case. The simple solution is to cut-out the shape and then cover the side of the case with black plastic tape and cut out the hole for the Micro USB Power.
PoE without a HAT
The Raspberry Pi 3 B+ onwards includes a PoE header on the motherboard.
(See the areas indicated in the image comparison below)
Raspberry Pi 3B+ Raspberry PI 4B
Background to the project.
I needed a PoE – supplied headless Raspberry Pi running Kali using the on-board WiFi rather than a USB dongle. This is for a remote IOT project to monitor WiFi compliance using the on-board WiFi in monitor mode. The object is to have a box that can be deployed and plugged into a IT Rack at a location where the intended, supplied WiFi is suffering from interference from “other personal and prohibited” Access Points. When users at that location complained of poor WiFi connection in the past, luckily the culprits were found. However, their tactics and games is that they switch off and remove their own Access Points when the visiting Technical Team arrive (The give away is the white 4×4 and our corporate-branded clothes). You can imagine the wasted time travelling to the remote location to find all is well on arrival. Therefore, the Promiscuous remote IOT compliance device was born.
3A Buck converter and Diode Buck Converter fitted in Pi Case
Buck converter fitted in (fan assisted) case.
Many commentators say the buck converter reliability is poor. Maybe so in their design but the issue is cooling. The Voltage regulator in the cheap ones is soldered to the copper on the circuit board. In this design, the fan assist keeps the whole unit ventilated to avoid heat build-up. The PoE Pi was soak tested for 2 weeks in an IT rack in a non-airconditioned environment where the outside daily temperature is above 26’c during the coldest months. Note that the Pi is operating in Headless mode and therefore less power is consumed as a HDMI display is not driven.
The Diode is included as a precaution should the polarity be accidentally reversed.
Setup of the buck converter was made before installation, the potentiometer adjusted so the output was 5 volts. This is mandatory or the Pi will be permanently damaged if more than 5v is applied on the GPIO pins.
Connect Fan to Pin 2 and 9 and the 5v Power from buck converter to pins 4 and 6
Home Server based on a Raspberry Pi5 8GB
Most of my projects built on Raspberry Pi’s are radio related. Late to the game, I purchased my first Raspberry Pi’s in 2016, one of the Zero W’s and a Raspberry Pi 3. The Zero W was uses as a VHF noise and tracking generator for testing VHF commercial radios. The Pi 3 was used specifically as a IP remote USB to extend the distance from a Motorola DM4601 control station to the MotorTRBO server in a different room. I also used another Zero W in a security CCTV project which created its own WiFI hotspot and ran off one of the early Lithium PowerBanks. It was just to keep an eye on some of the office vehicles I had parked on my property for a couple of weeks. Also back in 2017 I used another Raspberry Pi3 to build a Retro game station. I managed to buy a mini Nintendo look alike case to house it in. I left all these devices in Mali where I lived for 4 years. Times move on!
Last year (2024) I managed to get a Raspberry Pi5 8GB model and a SSD interface. This is now a Home Server. Running Ubuntu server as the OS with Docker. I have projects running in containers and along with docker I have DVSwitch. The Containers have HamClock, ADSB server and a partially built packet radio BBS. This will get a overhaul when I’m back home since the family have had a new internet package upgrade and the installer decided to wipe all my settings in the router her re-used. All they did was swap the separate ADSL2 modem for a Fibre converter. Really? No one asked me why the mesh system had stopped working. I was rather cross with the installer for not bothering to ask if they wanted to keep the configuration.
The Raspberry Pi5 undergoing transferring the microSD card mage to the SSD
The Pi5 with its NVMe base and a WD Black SSD that they said wouldn’t work.