I've done digital signage, controlled servos, used them as cameras, the works.
Right now I have:<p>- A 5-node Pi 2 cluster running k3s.io (<a href="https://github.com/rcarmo/raspi-cluster" rel="nofollow">https://github.com/rcarmo/raspi-cluster</a>), and a separate Pi 2 I use as a Docker build box and local Docker registry.<p>- A Pi 4 as a "lab" desktop computer with an USB oscilloscope and FTDI cables to flash ESP8266 and Arduinos<p>- A Lakka.tv arcade/MAME box for the kids with a PS3 controller (no room for a proper PiCade, we just use the TV)<p>- A Pi 3A+ with a mic array for playing around with Google Assistant<p>- Another one that I carry with me as a “pocket server” to SSH into from my iPad over Bluetooth<p>- A Pi Zero W taped to the inside of my electricity meter trying to estimate power consumption (we have a spinning disk mechanical meter)<p>- Another Pi Zero W with an EnviroPi HAT that I use to demo Azure IoT solutions<p>- An ODROID U2 (Could be a Pi) running HomeKit and Node-Red for home automation, as well as a bastion container (all dockerized).<p>- A 3B hooked up to my 3D printer running OctoPi<p>And the list goes on. I have many older Series Bs lying around, and once used one to revive a dead synth whose MIDI keyboard still worked (I set up timidity and a sound font on it and it became the kids' piano).<p>I also ran a Plex server on a 3B until it became obvious that I needed to think about transcoding (but it worked fine for music).<p>You can do a _lot_ with Raspberry Pis.
I just hope they also beef up the 3A+ RAM at some point since 512MB RAM is too tight.
Built a marine navigation system as a fall-back chart plotter in the event the onboard system goes down while chartering.<p>After rolling my own OpenCPN on raspberian install I decide to go with Sailoog after a card corruption. The project has come a long way, Ive mounted in a Pelican case with IP67 USB ports and a touch screen. Have a USB gps antenna and an rtl-sdr dongle for AIS tracking. The whole thing is hooked up to a 20kmha battery that sits behind the screen. Works great for a whole weekend. The screen is only on when I need to look at it, otherwise it just runs and keeps my tracks for my log.
Showing the build status through a green/red LED (code available at <a href="https://gitlab.com/Piskvor/buildenlights" rel="nofollow">https://gitlab.com/Piskvor/buildenlights</a> ), displaying Very Important Numbers on a 7-segment display, tailing dev logs on the HDMI output, occasional SD card reader (only needs the card at boot for kernel+initramfs).
put together a tiny wifi hacking/testing stick with my pi zero w. i added a USB plug on it so i can just plug it into my laptop, ssh directly to it (not via wireless), and then use the wifi on the pi to do my wifi hijinx :).
this way i keep my host systems wifi "clean" and can use the pi zero as a standalone device without having to worry about power cables, wifi connections, etc.