I plan to make a new case for my Pi 4B and 5“ touchscreen, modelled on the old scavenged housing I currently use with a PI 2B and the same screen. Perhaps not the best case shape, but I have grown attached to it. The end result will be used as a digimode radio headend for an otherwise headless ICON 7100 radio, and occasional retroPi gaming device.

20/02/21
Starting with my trusty OpenSCAD template, I found that I was able to use combined minkowski functions to get the two types of edge bevelling needed for the look.

An incremental refining of the case will take place in the background. Meanwhile, I have taken delivery of more items related to the Pi4, namely the heatsink and UPS batteries. I had bricked the OS whilst attempting to install the touch-screen drivers, so I diverted to reinstalling the same OS with the updated TS drivers for Kali, getting me ready to start on the I2C UPS comms for battery state tracking. Once I know this works, I can incorporate the UPS and battery space in the case design.

Install order:

1. Install Kali Rolling (kali-linux-2020.4-rpi4-nexmon-64.img in this case) on to SD card, fit the Waveshare 5" HDMI TFT to the Pi.
2. Add the following to the default config.txt to enable the Waveshare 5” HDMI full screen area and touch panel drivers from the get go.

   hdmi_group=2
   hdmi_mode=1
   hdmi_mode=87
   hdmi_cvt 800 480 60 6 0 0 0
   dtoverlay=ads7846,cs=1,penirq=25,penirq_pull=2,speed=50000,keep_vref_on=0,swapxy=0,pmax=255,xohms=150,xmin=129,xmax=3976,ymin=207,ymax=3975
   hdmi_drive=1
   hdmi_force_hotplug=1

3. Hook up Pi with a keyboard. Touchscreen drivers will work although calibration may be needed.
4. Start Bt and enable on boot.

   sudo /etc/init.d/bluetooth start
   sudo systemctl enable bluetooth

5. Add BT Keyboard & Touchpad as trusted device(s)
6. Fit UPS plus (EP-0136), LiPo batts, configure I2C for RTC and battery state, add scripts
7. Test the 18650 LiPo batts are real, then maybe against their specs, and maybe get some Fogstar Li-ion 18650 batts also to compare against.
8. install I3 window manager
9. Install OBCD onscreen keyboard
10. add onscreen KB helper to gdm3 window manager
11. Install HAM radio meta-packages
12. Add auto-mounting udev for USB storage (for radio contact logging)
13. Add I2C trackball ?
14. Install OverlayFS and RO/RW switching scripts

27/03/21

The hardware has been assembled and python scripts ran to check the hardware heat dissipation and stability. Everything is in the green. I plan to finish the case design for test printing next.