More details about this project on Thingiverse : https://www.thingiverse.com/thing:2514014
Pursuing this exercise of integration and design of cases, here is the intermediate stage towards the development of a complete computer, in the UMPC size, running the Raspberry Pi version 2 board.
In this stage, it is the integration of a smaller screen but while keeping the same screen resolution of screen, which carries the work: the challenge consists here in not exceeding the size been imperative by the keyboard.
On the previous project Raspberry UMPC (https: // www.thingiverse.com / thing:2430252), the interface allowing to connect the screen mobilizes the GPIO port of Raspberry preventing the development of the other projects. That is why it showed itself simpler and more convenient to exploit the HDMI port but in a different format to authorize a big compactness but also an exploitation of the Raspberry port.
The stage is intermediate because the wireless connections is not integrated, the power is reduced compared with the third version of Pi, there is no sound and the battery allows a use, with WIFI and Bluetooth on, only for about twenty minutes. To finish, it is necessary to manage actively the strong heating of Raspberry Pi3.
Furthermore, this project is more complex and asks for an equipment (soldering for SMT component) and training to succeed in modifying electronic boards and in modifying the connector HDMI without destroying anything.
The first Raspberry UMPC project provoked a big interest for this computer to the point that he could possibly become a commercial project under the shape of a DIY kit for example. If you are interested, you can answer the following questionnaire to help to determine if this idea is viable: https://goo.gl/forms/Gfs5fyGjNHq9FU3E3. Thank you for your opinion !
Preparation of Raspberry : (you can follow this making of video : https://youtu.be/8U7VZhNOIM4)
To make before any modification of Raspberry : Prepare the SD card of Raspberry by following the instructions proposed by Waveshare for the lcd panel. Paired the bluetooth keyboard, parametrize the WIFI connection. Verify that everything works.
( Watch out, this intervention cancels the guarantee and can destroy Raspberry in case of errors)
To integrate Raspberry into the case, it is necessary to deprive it of practically all the connectors with which it is provided except the GPIO port. To do it, it is possible to follow the advice proposed by Adafruit: https://learn.adafruit.com/diet-raspberry-pi/steps
. Solder the FCP/FFP connector instead of the original HDMI one.
( Watch out, this intervention cancels the guarantee)
Tear down the keyboard, peel back and unsolder the battery (Warning danger of short circuit) so as to release the electronic deck.
Cable the deck for the supply in 3,7 volts taken by the Raspberry Pi board on Pad PP8 for 3V3 and PP3 for GND.
Prepare the screen by unsticking the LCD panel (very fragile Warning : break very easily...). Clean both surfaces: board and LCD backward by removing the adhesive tape. Deprive all the connectors, solder the connector FFC / FPC instead of the HDMI. Recut the electroni board. Keep the micro switch and cable the ignition of the backlight.
( Warning : respect usual precautions and manipulation of batteries Li-Ion which can catch fire and explode in case of bad manipulations)
Delete the connector of battery, solder the battery wires instead. Use the small switch and cable it to command the switched on of the powerboost. Cable the set according to the instructions for use proposed by Adafruit for his module.