---
layout: post
title: "Portable Pi: Cheap Raspberry Pi Zero Hacker Terminal"
date: 2020-09-16
---


*I recently came across [the incredibly cool design](https://n-o-d-e.net/zeroterminal3.html) for an "ultimate Raspberry Pi computer"* by NODE and was inspired to create my own "portable" Pi device. Although, with my concept, I decided to set a few restrictions on the build:

- I wanted to keep the total cost as low as possible 
  - including the Pi Zero *and* extra hardware
- I wanted to avoid any custom casings or need for 3D printed materials
- I wanted to make the full design extremely portable / lightweight
- I wanted to keep the build as user-friendly as possible (no soldering, odd hacks etc.)

With these constraints put in place, I built my very own Raspberry Pi Zero "hacker" terminal. You can see the finished product below:

![Portable Pi front](/public/images/portable-pi-1.webp)

![Portable Pi back](/public/images/portable-pi-2.webp)

I'm pretty happy with the final outcome and best of all - you can easily recreate this yourself with little-to-no effort!

So enough chit-chat - let's build this bad-boy!

> **Note:** Most items in the hardware section are Amazon affiliate links

## Table of Contents

1. [Setting Expectations](#expectations)
2. [The Hardware](#hardware)
3. [The Software](#software)
4. [Getting Setup](#setup)
5. [Final Summary](#summary)

<h2 id="expectations">Setting Expectations</h2>

**This hardware will not** replace your laptop or any other "high-powered" portable device. Honestly, you're mobile phone would (most likely) work better in terms of a compact-sized computer. The concept behind this "portable pi" project was to make something *for fun*.

Please reserve any sassy comments about how buying a cheap $50 laptop off eBay would be more efficient than building out something like I have done here. You're missing the point entirely.

Moving on for those still interested... 

<h2 id="hardware">The Hardware</h2>

I live in Canada, so some of the options are based on available hardware near my location. You're likely to find similar hardware close to your own country for better pricing / shipping costs.

> **Note**: I've decided to use a wireless, USB dongle-based keyboard. You can opt to use a bluetooth-based keyboard, but I just find them more trouble than they are worth (keeping a charge, losing connections, interference from other devices)

- SBC: [Raspberry Pi Zero WH](https://amzn.to/3jCVXHG)
- Storage / OS: [64GB Micro SD Card](https://amzn.to/2GHm01R) (Always have an SD backup!)
- Battery HAT: [Li-ion Battery HAT](https://amzn.to/3jGq8xp)
- Battery: *This depends on your location. I was able to order [online through Walmart](https://www.walmart.ca/en/ip/Brand-New-4-Pcs-2500mAh-TR14500-3-7V-Rechargeable-Li-ion-Battery-for-Flashlight-Torch/PRD3Z73LMZZ3VK9), but if you live in the USA there are plenty of battery-specific vendors available. Find whatever works best for your needs!*
- Display: [KeDei 3.5-inch TFT Display](https://www.buyapi.ca/product/3-5-inch-raspberry-pi-tft-display/)
- Keyboard: [Mini USB Wireless Keyboard](https://amzn.to/2Gqkwt6)
- Adapter: [Micro USB OTG Cable](https://amzn.to/36I6T3c)

#### Raspberry Pi Zero WH

You will need a Raspberry Pi Zero W with GPIO header pins already soldered on to the board. (You could also do this yourself manually if you have the tools and skill to do so)

#### Li-Ion Battery HAT

This HAT holds a single li-ion battery and for our purposes will connect with our Pi Zero via the GPIO header pins. You could also look into double-set battery HATs if that is something you would prefer - for my needs a single rechargeable battery works fine.

Since our main "OS" is purely terminal based, I find you don't really need a li-ion battery with a massive amount of power storage. 2500mAh will easily last a handful of hours mucking about with emails, files and web browsing. Plus, you can always carry a few extras for swapping out on-the-go.

#### 3.5-inch TFT Display

A simple and fairly cheap touchscreen display. We won't require our display to render videos or pretty graphics (since we will be entirely terminal-based) so this works just fine for our needs. I am using version 6.3 for this build.

#### Micro USB OTG Adapter

As mentioned above, this item is optional if you feel more comfortable with using a pure bluetooth keyboard. I just personally prefer this method.

#### Wireless Keyboard

In my product demo image at the beginning of the article, I'm actually using an old Logitech wireless keyboard since this one still hasn't arrived. I plan to swap them out once I have it - the Logitech is far to large to be deemed "portable".

<h2 id="software">The Software</h2>

- Operating System: [Raspberry Pi OS Lite](https://www.raspberrypi.org/downloads/raspberry-pi-os/)
- Display Driver: [KeDei 3.5 Driver](http://kedei.net/raspberry/raspberry.html)
- Email: [Neomutt](https://github.com/LukeSmithxyz/mutt-wizard) (via Mutt Wizard)
- Web Browser: [Lynx](https://lynx.browser.org/)
- Text Editor: [Nano](https://www.nano-editor.org/)
- Code Editor: [Vim](https://www.vim.org/)

<h2 id="setup">Getting Setup</h2>

I will be setting up this "portable pi" via [headless installation](https://www.raspberrypi.org/documentation/configuration/wireless/headless.md) with my main [Raspberry Pi 4 desktop](https://uglyduck.ca/my-pi-desktop/). Included below are some quick instructions on how to setup the Raspberry Pi Zero for `ssh` access.

#### Preparing the microSD card

- Use Raspberry Pi Imager to write the Raspberry Pi Lite OS to your microSD card
  - Once complete, remove the microSD storage device and then re-connect it
- Navigate to the `boot` folder of the microSD device - we will be adding 2 files here
  - First add a completely empty file and name it `ssh` (no file extension)
  - Next add an empty file named `wpa_supplicant.conf`
- Open the `wpa_supplicant.conf` file in a code / text editor and paste the following (be sure to change `country` to your proper country code, as well as properly setting your network name / password):


    ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
    update_config=1
    country=US
    
    network={
        ssid="Your network name/SSID"
        psk="Your WPA/WPA2 security key"
        key_mgmt=WPA-PSK
    }


- Unmount the microSD device, then place the microSD card in your RPi Zero
- Assemble the Raspberry Pi Zero with the Battery HAT (li-ion battery attached) connected via GPIO pins, and the 3.5 display connected on-top of the battery HAT's pins
- Turn on the battery HAT switch to power the RPi Zero. Give the device roughly 90 seconds to perform the initial boot

> **Note**: the display will turn on but only show a white screen - this is normal

#### Connecting to your Zero via SSH

Open the terminal on your Raspberry Pi desktop and enter the following command:


    ssh pi@raspberrypi.local


You will then be asked if you wish to trust this device (say yes), then prompted for the `pi` user's password - which is `raspberry`. After a moment you will be directly connected to your Raspberry Pi Zero. Hooray!

We just want to make a couple small configuration changes before going forward (mostly for security):

1. Run the command `sudo raspi-config`
2. Select "Change User Password" from the menu and change the password
  ![Raspberry config](/public/images/raspi-config.webp)
3. After that, select "Network Options" and change your device name
  - This will avoid any conflicts of connecting to newer RPi devices down the line

That's it!

#### Installing display driver

Next we will need to download and run the drivers needed for our 3.5-inch display to play nicely with our Pi Zero (just a blank white screen doesn't help us much). While connected to our RPi Zero via SSH, run the following commands:

    wget http://kedei.net/raspberry/v6_1/LCD_show_v6_1_3.tar.gz

If you have snail-paced rural internet like I do, now is a good time to go and grab a coffee while this download completes.

Once the download has finished, extract the contents and navigate to the new directory and install the driver:


    sudo tar xzf LCD_show_v6_1_3.tar.gz
    cd LCD_show_v6_1_3
    sudo ./LCD35_v


Once completed, the RPi Zero will reboot and everything should work as expected!

#### Installing software

I'm not going to jump into heavy details about installing terminal-based software for this setup. The links I've attached in the software section should provide you with more than enough information to get started. For reference, I'm using a very basic set of applications:

- Neomutt (emails)
- Lynx (quick and simple web browsing)
- Nano (writing notes / blog posts in a hurry)
- Vim (making any config edits or project work)

<h2 id="summary">Final Summary</h2>

There you have it - a terminal-based, portable Raspberry Pi Zero "hacker" device. 

Is it practical? Not really. Can it replace any other *portable* device you might own? Probably not. Is it fun to make and experiment on? You bet! And in the end - isn't that what matters most with pet Pi projects?