All in one aluminum case for 80 mm instrument hole with Epaper display and Bluetooth - TomBric/stratux-radar-display GitHub Wiki

Everything you need for a full stratux installation in your airplane.

List of materials

Everything you need for a stratux with OGN transmit capabilities, see here on the main stratux page
- Stratux 3B+, welectron or other suppliers
- T-Beam, amazon or other suppliers. Use the version with Neo 8M GPS
- NoElec SDRs, amazon or other suppliers
- GY 91 sensor (BMP280, MPU 9250), amazon
- Short USB cable, many types, e.g. amazon
Step-Down power converter to connect to 12 or 24 v: LM2596 (lots of suppliers), ebay
Rasperry Pi Zero 2 W, many suppliers, e.g. welectron
3.7 inch Epaper display 18381, waveshare, e.g. supplied by welectron
Epaper Driver Hat 13512 (universal) waveshare, e.g. supplied by welectron
SD card extender to be able to access the SD from the front, e.g. supplied by reichelt
Aluminum sheets 0.5 mm thick for the case and a small part Aluminum sheet 1.0 mm for the back of the case. The case has dimension 72 x 44 x 150 mm (There is no need for aircraft grade aluminum, simple AlMg3 works good and is easier to bend)
3D printed front. I suggest ASA material, e.g. 3Djake
3 x micro switches 6x6 mm, length 17mm or 20mm (lots of suppliers, reichelt or ebay)
silent cooler fan Noctua NF-A4x10 5V, e.g. available here amazon
distance holder (brass) and screws 2.5mm, lots of suppliers, e.g. amazon
I use simple BEC connectors to connect to the aircraft power, e.g. here ebay
M3 screws to build the aluminum case and M4 or M3 screws to fit the instrument into the airplane.
small black M2 screws for fixing the epaper-hat and the micro switches, e.g. amazon
depending on your installation, you additionally need external antennas as well as an external gps receiver, e.g. reichelt

3D print files

OpenScad (if you want to modify something) source
STL-File (for direct printing) source

Hints for building

First 3D print the front, consisting of 3 parts: front, cover and latch for the micro switches.
First mount the Epaper-adapter into the space inside the front (use 2 mm screws for that)
Connect the epaper display (be careful). If you want, you can just clue it on the front.
Put the cover on top of the epaper and front and push slightly. The epaper display should now be held exactly in the front/cover.
Install and solder cable to 3 micro-switches (17 mm or 20 mm long switches). Install the micro-switches in the front, using M2 screws and using the printed back-latch
Install the sd card extender in the front and fix it from the back with hot-glue
Cut the aluminum case consisting of
- part 1 "main": cut (57+9+30+9+57)mm x 150mm from aluminum 0.5 mm. Bend 45 degrees 4 times at 57 + 9 + 30 + 8 + 57 (see pictures below)
- part 2 "top cover": (10+9+30+9+10)mm x 150. Bend 4 times at 10 + 9 + 30 + 9+ 10.
- part 3 "backside": cut 1mm aluminum with a size of 76 x 60 mm. Draw lines horizontally at 8 + 7 + 30 + 7 + 8 mm. Vertically at 8 + 7 + 53 + 7 + 8 mm. Cut all corners at 8 + 7 = 15mm. Bend inside all 8 mm flanges 90 degrees. 1mm aluminum is preferred here to be able to top the thread into the aluminum.
put the case together and drill holes at the front and the backside. Tap 3 mm threading into the front and the back.
Install the T-beam on the left side of the case with 5 mm brass holders. Connect the antenna and gps via an ipx-sma cable.
Install the Pi Zero 2 W on the bottom of the case. Take care to face the sd-card to the back, so that you can access it from the back. Solder the epaper-hat cables to the GPIO-Pins of the Pi Zero.
Install the epaper-connection-hat partly over the T-Beam. You can use 3 12.5 mm brass holders and partly overlap it over the T-Beam.
Install the LM2596 step down converter also on the left with 5 mm brass holders.
Install the fan on the right side using the noise dampeners. Cut opening holes to get enough air out or in on the right side.
Install the raspberry 3B via at least 20 mm long brass holders on the right, just on top of the fan.
Install all 4 SMA connectors at the back. Cut holes in the back to get air flow into the case.
Adjust the LM2596 step down converter to an output voltage of 5 V. Do this by connecting the input to some voltage between 8 and 40 V. I use an old laptop power supply with 19 V.
- Connect all cables. Some hints for the connections:
  - Power connections to raspberry PI 3B: You can solder power cables to the Pi 3B by
    
    Cable Connection Point on Pi 3
    
    VCC + 5V PP2 point (near the USB mini power connector)
    
    GND Solder to large fixing point of network or USB connectors
  - Power connections to a Pi Zero (if you use one) : Since the zero has no voltage protection, you can directly solder the power cables into the GPIO holes:
    
    Cable Connection Point on Pi Zero or Zero2
    
    VCC + 5V PIN #2 or Pin #4 at GPIO
    
    GND PIN #6 at GPIO
  - Connecting the GY-91 Gyro Sensor and Barometric Sensor: Solder the cables on to the GY-91. On the Pi you either have to solder cables to the GPIO pin or the better choice is to connect via crimping of "Dupont" connectors to the GPIO pins
  Connection on GY-91 Connection Point on Pi 3
  
  VCC +3.3 V PIN #1 at GPIO
  
  GND PIN #9 at GPIO
  
  SDA PIN #3 at GPIO
  
  SLC PIN #5 at GPIO

Cable	Connection Point on Pi 3
VCC + 5V	PP2 point (near the USB mini power connector)
GND	Solder to large fixing point of network or USB connectors

Cable	Connection Point on Pi Zero or Zero2
VCC + 5V	PIN #2 or Pin #4 at GPIO
GND	PIN #6 at GPIO

Connection on GY-91	Connection Point on Pi 3
VCC +3.3 V	PIN #1 at GPIO
GND	PIN #9 at GPIO
SDA	PIN #3 at GPIO
SLC	PIN #5 at GPIO

All in all the space inside the case is limited, so it will take some consideration and care when putting it all in. But it works and fits. Cooling should not be a problem, the fan cools enough for all components.

As a final step install stratux on the Pi 3B using the sd card in the front. Install the display software on the Pi Zero.

Here are some pictures from the building process.

Building process