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Inherently Programmable Pi

I’m teaching a small robotics class, we’re making the small Etch-a-Sketch plotter. Just a couple of kids, good eggs from the 5th grade X,Y coordinates class I teach every year. I’ve already done similar classes in various contexts, it’s a ton of work but very rewarding. One thing I always seek to improve is my Pi image management. Depending on the kids & material, we’ll go through some Linux CLI, or I won’t even want them to touch Linux but we’ll still have to click through some things to get going on Python to control GPIO pins.

What I’ve been wishing for for a while, is a Pi that’s always online everywhere, with the quickest way to get to just Python. Hopefully something web based so you don’t need anything other than your old faithful browser to start throwing code at GPIO pins.

Introducing IPP, the Inherently Programmable Pi! An image you can download, or build.

Step 1 – Python Forking Web Code Editor

And so step 1 is obvious, I want the Ace web based code editor, preset to Python settings, and served by the very Pi it’s meant to write code for. With a few buttons for running code, stopping it, and checking the output.

AI made that a breeze to code, it always blows my mind how well it understands even convoluted assignments. There’s some pretty gnarly stuff going on there. Python runs a web server that serves a coding environment that can fork another Python process, and kill it with varying degrees of prejudice when it won’t go away on its own. I want this packaged a a single Python file with all the bits and pieces bundled in. AI got all this with little help.

Step 2 – Zerotier & Public Bridge

For step 2, I want the Pi to be easily accessible online, no matter what crazy wifi it’s connected to. For this we’re using Zerotier, and an online bridge that is publicly available to forward traffic into it. In my case this is done with Traefik and a Docker container dedicated to forwarding into Zerotier. I unfortunately can’t offer this part of the stack with the image, but you can at least specify a Zerotier network ID as a tunable when building it.

This way, no matter what Wifi network your Pi is connected to, it will always be available via a public URL.

Step 3 – Local Wifi when Nothing Else

I wanted to take the script that turns PlottyBot into a hotspot if it’s not connected to the internet and modernize it for the newest Rapios (Trixie). I also want the web interface to let you connect to existing Wifi networks. This way you are either in a spot with no Wifi, and your Pi spawns a local one which doesn’t route to the internet but you can still program. Or there is pre-configured known internet Wifi within range and your Pi connects to that.

Of course AI yet again turned a multi-hour endeavor into a 30 minutes one. Well, it did mess up some fundamental things but still, I was spared hours of grinding.

Step 4 – Easy Imaging

Finally, I want to create Raspios images with all this and a few tunables baked in. No booting each one to install stuff & tune it for each kid. For this I’m using something I built years ago for mounting *.img files and tweaking them. It’s a Docker container you can pipe an image file into and out stderr comes the customized image. This might be worth its own post, I’ve used this for years to great effect, but that’s beyond the scope of this post. The point is it’s available to use, and here’s how:

Build Your Own Image

First download & decompress the latest Raspios:

wget https://downloads.raspberrypi.com/raspios_lite_arm64/images/raspios_lite_arm64-2025-10-02/2025-10-01-raspios-trixie-arm64-lite.img.xz
unxz 2025-10-01-raspios-trixie-arm64-lite.img.xz

Then download & decompress this project’s files to tweak it with:

wget https://ben.akrin.com/downloads/ipp_2025-11-11.zip
unzip ipp_2025-11-11.zip

Finally, create your customized Raspios image with:

sudo docker run --rm -i \
    --name=raspi-image-customizer \
    --cap-add SYS_ADMIN --privileged \
    --device /dev/loop0 \
    --platform linux/amd64 \
    --cpus="1" \
    --memory="500m" \
    -e HOSTNAME=mypi \
    -e HOTSPOT_WIFI_SSID=mypiwifi \
    -e HOTSPOT_WIFI_KEY=raspberry \
    -e ZEROTIER_NETWORK_ID="<ZEROTIER_NETWORK_ID>" \
    -e PIPASSWORD="raspberry" \
    -v ./ipp:/data registry.akrin.com/raspi-image-customizer:latest < 2025-10-01-raspios-trixie-arm64-lite.img 2> ipp.img

–cap-add SYS_ADMIN, –priviledged, and the loop0 device are necessary to mount a file as a disk inside the container.
HOSTNAME is evident
HOTSPOT_WIFI_SSID & HOTSPOT_WIFI_KEY are the settings for the local wifi network that the pi will spawn when it has no known networks to connect to.
ZEROTIER_NETWORK_ID is optional, if specified the pi will join it first chance it gets (when connecting to a managed wifi that routes to the internet).
PIPASSWORD is the password for the pi user, careful SSH is enabled in this image.

You can burn the resulting ipp.img to an SD card. The first boot will be longer than the subsequent ones as stuff gets initialized, but eventually you’ll see a new wifi network pop up. Connect to it, and point your browser to http://hostname.local or if that doesn’t work http://192.168.50.1, you will see the coding web interface. Now that might be enough for your to start coding, but if you want you can click on the wifi network icon at the top right to specify a standard network to connect to. And if you do so, I recommend you have a way to “follow” your Pi, either via Zerotier, or because you manage that network and are able to see what IPs devices get assigned. And if you setup a Zerotier forwarder on top of all this, your pi essentially becomes online to the world the minute it’s on. Now that isn’t just convenient, it also significantly lowers the bar to start coding with kids.

Or… Download a prebuilt one

Here’s the link.

parameters used for building it are:

HOSTNAME=ipp
HOTSPOT_WIFI_SSID=ippwifi
HOTSPOT_WIFI_KEY=raspberry
PIPASSWORD=”raspberry”

No Zerotier, but still everything else.

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X,Y Coordinates

Some of the tools I’ve accumulated over the years lend themselves particularly well for teaching. I’ve gotten better at swooping in a classroom with some plotters and talking about math or machine drawing topics. I can make it very interactive.

One tool in particular is https://draw.mandalagaba.com.

It started not so much for teaching, but rather for collaborative art. Very much inspired by r/Place, I created a tool with real estate scarcity, but with my usual focus on drawing. The kicker would be that the art is rendered live on a plotter somewhere in the world, maybe in front of you in a public place, maybe a video stream and you know your pen strokes are executed by a machine thousands of miles away. You claim a square, coordinate with others to make bigger pieces, and a collaborative art piece is born. That was the idea at least. I’ve tried several permutations of this experiment, in public, on a stream, with various rules and online communities, and it simply never generated the enthusiasm I thought it would. I have 95% given up on the idea of a collaborative art piece of the sort. The big plotter still has me wondering hence the remaining 5%, but it is tedious and expensive to deploy for an experiment that has shown no promise at every iteration.

What this website became great for however is teaching as it allows for time sharing a drawing machine across several students. We can explore one concept or other, and then apply it and have the great motivator that we’ll get to control the machine by doing so. 3 years ago I taught a module on X,Y coordinates with the local 5th graders, I didn’t have this site then and it went fine. But the following year I figured I might as well use this dumb collaborative art website I made for something so I integrated it into the coursework. Now that second year The machine’s made an enormous difference in how students engage. Recently I ran this course for the 3rd year with the website and the magic happened again. Both times, kids were very much willing to go through teeth grinding (light X,Y coordinate based coding), and help each other out to see their work realized in the world by a cool machine. The first student that submits a drawing on the site inevitably has everyone jumping off their seat to see the machine move up close. Then they’re even more motivated to do it themselves. I help them with the mistakes they make at first, and once they get it I have a good half an hour of walking around and seeing the cool stuff they draw. During this time I might send one drawing machine on a more intricate plot that can finish quick. Having that plotter wield a pen expertly inevitably draws 2 or 3 kids who just sit and stare at the machine non-stop. I know what they’re going through. The whole experience has them asking so many questions, and I love interacting with the different ways in which they see the world. I also love the opportunity to get to know every kid in town a little better when they go through 5th grade.

I’m quite glad that these tools found a place in education. Sometimes I think of pushing further, there’s definitely something to this formula, and I know teachers often purchase various curricula or interventions that meet a standard or other. But I can’t push all the projects, and so far I’ve refused to let money taint anything plotter related.

Funnily enough, I even had an opportunity to guest lecture in the same way with college art students. Of course we don’t talk about 5th grade X,Y coordinates, and I’m not there to talk about art either. Rather we learn and employ tools and techniques for line art and single instrument machines. It’s only funny because I’m ashamed to admit I’ve been very dismissive of art (except music) my whole life. I never understood it and wasn’t a fan of the carefree personalities gravitating to it. I’ve seen the light now, and I do feel apologetic for the times someone showed me a something they had made and it went completely above my head. But I can’t say I was particularly impressed by the students. I’m definitely curious to try again and see if I can bridge more understanding. In the meantime, I have no issues resonating with 5th graders so I’ve got that going for me :). Except for keeping them focused, that is insanely hard.