Quick Tech Post: Raspberry Pi is a really useful platform…

I have two Raspberry Pi computers. If you’re not familiar with the brand, they are a UK based company that has created a simple computer-on-a-card model with the intent of keeping cost down to allow the teaching of computer-related subject in developing countries. The original version was released in 2012, and I got mine in 2013ish, I guess. I bought it to teach myself a bit about Linux computers and, well, because it was such a cool idea! The Pi uses SD cards for storage, although it’s a simple hack to add an external USB drive if you want. In any case, after a couple of months the original Pi was replaced by my Dell server as I wanted to run things that needed a bit more horsepower than this blog.

In fact, for several years, until last week, the original Model A ($20) plus case, sat without a mission. It’s sibling, a Model 2 B ($35, plus case) was occupied as an SSH “front door” to my network and a personal proxy server. I’ve switched things around a bit in the last couple of weeks in that I re-purposed the Model 2 into a dedicated controller for my Reprap 3d printer.

Prior to doing that, I created an image of the SD card with the intent of re-flashing the Model 1 and installing it as the front door. “With the intent” is the notion upon which to to keep an eye… I wasn’t at all sure that it would work on the original Pi and had visions of reinstalling Raspian (Debian Linux based distro for the Pi) and configuring it from scratch. Not a huge deal, but still, I though that I’d rather go with the familiar server setup if possible.

The RPi 2 installed in its new location on the printer. I’ve since added an enclosure similar to that for the electronics (on the right). The USB cords on the left are for a webcam and for the printer. There’s also a network cable and a micro USB for power into the Pi.

The switch was actually simpler than I thought it might be. Imaging the Model B was quite simple. I downloaded an image of OctoPi, the Raspberry Pi specific distribution of Octoprint printer control software. The install instructions called for using balenaEtcher package to flash it to the SD and the backup image was self explanatory. Flashing OctoPi was simple as well and I was up and running within minutes after the flash. A couple of days later, when I started to miss my front door, I flashed the old image to the SD card for the Model A and held my breath while it booted. Long story short: the hardest part of the evolution was tracking down the IP that my DHCP server assigned the new Front Door so that I could SSH into the box and switch it to the IP formerly held by the other unit. I also removed some LAMP related software as it was not being used in this application. The Model A runs noticeably faster as a result.

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