Handheld Raspberry Pi Computing Box

A Raspberry Pi is a nice Linux board to do just anything computer related that is not too intensive.
With its low power consumption and compact size, it can be ideal even for portable use, with a bit of DIY.

- Raspberry Pi (any model, I have a 3B, but the Zero might be better for its small size)
- Small enough display (mine is 3.5")
- Small keyboard of the generic TV box kind (see mine)
- Already prepared SD card, with the OS you like set up and all needed drivers (for example, for GPIO displays)
- A powerbank
- Some spare cardboard sheets and a carboard box
- Adequate cables to connect all your parts

Before we get into the actual work of making the handheld, let's start with an overview of the project.

We will get a Raspberry Pi, with a small screen and keyboard attached, powered by a powerbank, all inside a little box which can be closed and taken around safely in a bag, and reopened at any time to do work.

The image on this section should give you an idea of all the actual tech parts needed, still outside the box.

Before knowing what carboard to get, you should first get all your parts measured.

My box is 15x12x4 cm, which is good for my 14x10 keyboard and 5x10x2 powerbank. It's the best I could find around my house for this.

However, since it is still not perfect for all the elements, I needed to create some spacers, of course with cardboard.

The sheet spacer seen in the picture is needed to divide the box into two vertical sections:
- The bottom one with all the cables, the powerbank, and the Raspberry Pi
- The top one, with space for the screen and keyboard

The pillar spacers help to keep the powerbank in place, you will see why in a bit.

You might need to do some changes to the box, depending on how yours is.

I, for example, had to cut a hole on the side, to be able to expose the powerbank's USB port, where I would manually connect or disconnect the USB cable to power on or turn off the Raspberry Pi. If I had an USB cable with a button on it, this would have been much cleaner for sure.
Because the USB connector gets to the side of the box, I also had to cut off eccess cardboard from the upper flap, or the box wouldn't close without disconnecting the cable, and that wouldn't have been good for closing it temporarily (ex. for transport)

Now it's time to get into preparing the main functional parts.

First thing, get your mini keyboard, and disassemble it to remove the plastic back, necessary to make the whole system slimmer. I had to do this or the keyboard wouldn't fit how I will later show.

Start also connecting everything, (except for the powerbank, that would power up everything): the screen to the Pi, the keyboard to the Pi too (and make sure to turn its power switch on), insert your microSD in the Raspberry Pi, and also connect the USB cable for the powerbank to the Pi's micro USB / USB C port.

The project's core is the box, so let's put everything in it.

Starting with the powerbank, I put it on the bottom, with the output USB port near the hole made earlier. If you'd like, make an additional hole to access the port for charging the powerbank. I didn't, so I would need to take it out from the box when its battery goes flat.
The pillar spaces made earlier are nice for making sure the powerbank doesn't move away from the port when trying to connect the Raspberry Pi's power cable.

Then, I put in the Raspberry Pi itself on the left, with the power cable attached earlier going out the hole on the side.

Finally, I lay down the carboard sheet between the Pi and the screen, and also fit the keyboard in that small space, routing its cable below the cardboard.

That's all!

Look how the final result is, both closed and opened for use! You can do all the handheld Linux computing you want on something like this, and it should last some hours even on small capacity power banks.