A wise colleague once told me, "If there is something that can take any data, build a schema, and lets you mount it somehow, it's going to have many use cases." That sent me down the path of looking at ways to easily surface important details and to make querying that data responsive. By dynamically generating the needed information instead of building static representations, you can quickly integrate this data into other systems and can modify it on the fly without needing to change the underlying systems. I described this type of solution in my previous blog article, "Building a Federated Data Caching Appliance."
With the release of the 8GB version of the Raspberry Pi 4, there seemed to be an opportunity to build a low cost solution based around those principles.
Table of Contents
Part 1: Overview of the Components and Their Assembly
There are of course many options for building such a device. Keep in mind that this is 100% unsupported by Radiant Logic as it is not a supported platform.
I am breaking this out into four articles:
Overview of the Components and Their Assembly
Base Install and Configuration
Radiant Logic Install Instructions
Implementing the Use Case
There are many ways to do this. I have chosen these steps to make things easier for me. Please keep that in mind as you review these instructions.
I would like to recognize an article called “Getting Started with Raspberry Pi 4” by Crosstalk Solutions that helped get me started with the Raspberry Pi and its configuration.
Components
Before getting too far into this, I wanted to list out the various components I used in this proof-of-concept. I decided to simplify things by using Power Over Ethernet (PoE) instead of plugging in the Raspberry Pi’s. This made it easier for me to manage the jumble of cords I needed. If you do not have a switch with PoE capabilities, be sure to use a power supply instead.
A great way to get started with all of the needed components is by leveraging CanaKit’s Raspberry Pi 4 Starter Kits. I highly recommend them. I have no affiliation with the company. This gets you going with everything you need.
So, onto the list of equipment.
I used the following items as part of this build:
3 x Raspberry Pi 4 8GB - https://www.canakit.com/raspberry-pi-4-8gb.html
3 x Power Over Ethernet Hats - https://www.canakit.com/raspberry-pi-poe-hat.html
3 x MicroSD Cards: https://www.canakit.com/raspberry-pi-sd-card-noobs.html
1 x Micro HDMI Cable - https://www.canakit.com/raspberry-4-mico-hdmi-cable.html
1 x Micro USB Cable (Pi 4 kit) - https://www.canakit.com/raspberry-pi-4-complete-starter-kit.html
3 x Heat Sink sets - https://www.canakit.com/raspberry-pi-4-heat-sinks.html
1 x HDMI Display - https://www.amazon.com/gp/product/B07WW4GMVR/ref=ppx_yo_dt_b_asin_title_o06_s00?ie=UTF8&psc=1
1 x Keyboard - https://www.canakit.com/raspberry-pi-wireless-keyboard-rii.html
3 x Ethernet Cables - https://store.ui.com/collections/unifi-accessories/products/unifi-ethernet-patch-cable-with-bendable-booted-rj45
3 x HighPi Raspberry Pi Case for Pi4 - https://www.pishop.us/product/highpi-raspberry-pi-case-for-pi4/
3 x GPIO Stacking Header for Pi - https://www.pishop.us/product/gpio-stacking-header-for-pi-extra-long-2-20-pins/
3 x 2X2 Pin - https://www.pishop.us/product/2x2-pin-2-54mm-double-row-female-straight-header/
3 x Brass Standoffs, M2.5 x 15mm - https://www.pishop.us/product/brass-standoffs-m2-5-x-15mm-package-of-8/
Screwdriver (I didn’t use it, but it can come in handy)
I used 11, 12 and 13 in order to still have access to the GPIO pins and also to raise the PoE Hat enough to make space for the heat sinks.
Assembly
The following steps outline the how I assembled the Raspberry Pi’s. There are probably a million ways to do this. This works for me. Do it your way if you want.
1. Remove Raspberry Pi from box
2. Attach the heat sinks (please refer to the excellent diagram from CanaKit in their Quick Start Guide (https://www.canakit.com/Media/CanaKit-Raspberry-Pi-Quick-Start-Guide-3.2.pdf), which I also used to help identify these steps
a. Remove the heat sinks from the plastic
b. Peel off the protective film from the heat sink
c. Press the heat sink onto the Raspberry Pi using the CanaKit diagram above
1. Attach M2.5 x 15mm Standoffs, 2X2 Pins, and GPIO Stacking Headers
a. Attach the standoffs using the supplied screws to the board at the four hole points – I personally do this finger tight
b. Push the 2x2 Pins onto the PoE Header (see diagram in step 2) – Be careful not to bend the pins
c. Push the GPIO Stacking Header onto GPIO Header (see diagram in step 2) – Be careful not to bend the pins
1. Attach PoE hat
a. Remove the PoE hat from the box and static bag – you can discard the screws and standoffs that came with the PoE Hat
b. Carefully press the hat onto the GPIO and PoE Header pins
c. Screw the 4 nuts onto the standoffs
1. Put the Raspberry Pi in its case
a. Attach the feet to the bottom of the case
b. Flip over the case and follow the instructions printed in the case
c. First insert the front of the board and then snap it into place
d. Snap the lid into place
6. Set up a monitor and keyboard If Desired (we will use ssh in this set of instructions)
Attach the Raspberry Pi to a USB keyboard and HDMI display if desired. A HDMI television will work as well. The HDMI port on a computer will not work since it is out, not in. If you want to capture this onto the computer, use a capture card. Keep in mind the USB-C port on the Raspberry Pi is used to power the unit if you are not using PoE. I have a different keyboard in the image below, but it wasn't used in the configuration.
Refer to the diagram in section 2 for the connection ports.
This article continues in Part 2 - Base Install and Configuration