Follow this guide to make one easly Fit take a look at this in 3D using AutoDesk Fusion 360 Online . There are some key features. ? Have RTC & buzzer. ? Supports v2 Add-o. ? A track point to have mouse support with left, right butto. ? Gyro support using MPU6050 module & presure, temp and humidity support usin BME280 module. ? Able to turn of modules, Display, Add-o using keyboard button. ? Full poweroff using OS and keyboard key. ? 12 pin docking port beside Pi USB ports with UART, I2C, Charging and GPIO. ? 3D parts are more solid and reduce supports when printing. ? Able to read battery voltage using Pro Micro. ? 2 LED's connected to Pro Micro with PWM support and 1 connected Pi. Move the stema/Qt I2c connector bottom so it is acessible from outside. ? It is fully open-source hardware. So you can Hack it as you can make your expaion-card like gps, Radio etc and attach with it. ? You can use any Raspberry-pi form factor like Asus Tinker Board S / PINE H64 Model B/ Banana Pi BPI-M4B etc. You can use Raspberry-pi zero to 4. ? You can access all the ports of the pi and the back part is attached with 4 screw. ? It can hold a 4" or 3.5" touch screen. Also have a physical keyboard attached via USB. ? 18650 battery with charge and discharge protraction . ? You can use Littlevgl make UI that don't need a OS form here. ? It don't need any custom image of Raspbian. You can use vanilla Raspbian and itall the LCD driver, that's it. ? So little parts needed to make one. See the parts_list . ? You can use C Suite Application suite made more touch based device in this. This apps are suitable for small scree. See the C Suite. ? Added Adafruit STEMMA QT and SparkFun qwiic connector. Youtube channel. Here is the Project website. Project files in Gitlab . So make you and help us to make a Community around it.