Instrument Case Computer
January 2019
This project was one that I had wanted to do after making my portable pocket computer because the restrictions the portable had: small screen, needed an external keyboard to easily use, low battery capacity, fragile. I started with a durable ABS instrument case, a large 10,000mAh power bank, a 7 inch lcd screen, a cheap usb hub, a small second hand keyboard from ebay and the pi.
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The main challenge of this project was creating mounts that would be as sturdy as possible while removing as little material from the case as possible.
The screen mount was the first part I made as its dimensions didn't have much room to change. In fusion I modelled the screen first just by using calipers. I then built a neater looking housing around it to print.
usb hub
The usb hub was going to essentially be the way to plug in any external usb device. Seeing as the keyboard, hub, touchscreen and a usb were going to be always plugged in having the ports accessible on the outside seemed redundant as they would always be occupied. I drilled 2 m3 mounting holes to attach the hub and 2 large holes at the rear of the hub 1 to run the wires through to the Pi and the other for the on/off switch.
I made a right angle mount for the Pi to keep minimal distance between the screens hdmi connector and the pi's. I had some concern about the strength. but was surprisingly strong.
Usb charging port
The battery case was very straight forward, much like the screen the dimensions were very dependant on the power bank I chose. It was mounted to the case with 6 m3 screws. I soldered a micro usb connector to make an extension cord to outside the case for charging, and the output of the power bank to the power switch. The other side of the power switch was soldered to a male micro usb extention cord that plugs in and powers the Pi.
Battery case
After settling on the larger of the 2 keyboard candidates I realised the holder from the pi was going to interfere with how I wanted to design the keyboard border. I redesigned and reprinted the mount for the Pi at an angle so I could design the border how I wanted to.
Revised Pi mount
The keyboard border was designed to have a slot at the bottom for the Pi GPIO and the opening at the top was for the hdmi and power cables for the screen. I printed the border in 4 separate sections and 3 corner brackets on the bottom to screw the keyboard to the case.the boarder was glued with epoxy to the keyboard and the 3 corner brackets. I had to remove some of the material from the lid with a rotary tool to get let the case close less tightly.
Keyboard corner brackets
After formatting the sd card with raspbian, plugging everything in and screwing everything that wasn't already screwed in place, the project is done! This was a really fun project and I now use this in place of my old laptop for pcb and schematic design, and programming other projects.
Fin~
