I have a unused RPi4 (the 8Gig one) running DietPi.
I did use it as a playground but ever since I am renting a Hetzner machine for (playground) stuff that I want web accessible, I don't have particular use for the Pi.
I am currently running (outdated) Home Assistant on it but there isn't much I can connect it with (yet, getting the flashable/compatible ikea smart lightning zigbee? bridge thingy is on my bucket list).
Obviously I do have a pihole there.
Shoot me any other ideas I could run there.
Some kind of monitoring of my rented infra would be cool (I already have uptime kuma on the dedi hetzner box). One idea I had was if there are some OSS security scanning "daemons" I could use on to monitor my other infra.
About a minute, 1:30 maybe (edit: per page on a pi4). I use an app to upload jpegs though, I don't have a normal scanner at the moment. The higher quality scan and smaller file size may make some steps of the process quicker (no need for alignment and color correction for example) if you use a normal, proper scanner.
It doesn't matter though. When I get home and see I got a letter I scan it and by the time I drank something, put away my clothes and stuff i had with me, the pi is done and I can edit the metadata in the web ui.
Most people seem to just want to use RPIs as a very slow Linux server for some reason...
Use it to play around with hardware integration with the GPIO pins. Get a sensor HAT and start recording temperatures, write some code that turns on/off an LED, build a robot controller, etc. There are lots of kits and documentation on the various things you can do!
It is! Especially if you want to write the code yourself. It's an interesting design problem if you start to consider cases where the PI may be offline (mobile on a battery in my case). Do you lose that data? Store and forward? In memory or to a local data store? It's a fun rainy-weekend project.
Word of caution - HATs can be a rather inaccurate in their temperature monitoring. The Pi gets warm. I had done my work using a PTC thermistor that was distanced from the Pi itself. I've got a friend using a HAT and it's been very off (up to 10C above ambient!). A Pi Zero may not give off as much heat as, say a Pi4 though. YMMV.
SBCs like the RPi are kind of awkwardly in-between a microcontroller like an Arduino or ESP32 that you can actually trust with handling GPIO and data logging, and a real Linux system that can actually do meaningful computational work.
Pretty much the only task I've found them reliably appropriate for is running OctoPrint, really really light computer vision tasks for robotics, or hooking up an RTL-SDR to use as a police/HAM scanner. Outside of those, it's so much easier to use either a cheaper and more reliable MCU or a much more powerful old laptop or desktop.
You can write code that has access to more resources. I had a RPI once that showed code build status on an led strip (red failed, green passed). It was a Java program that connected to AWS SQS for build event notifications. A micro controller would be much harder to do that on.
Unluckily last time I wanted to do sensor stuff the ~20 euro air quality multi-sensor (co2, pm1-10, humidity, voc?) board got lost in transit and I didn't bother since :(
The original plan was use it with my esp32 dev board (wroom32, so wifi) to have a portable sensor, this RPi was supposed to be the collection server (mqtt, influx, grafana).
I should revisit this idea soon, thanks for reminding me!
This! Im planning on getting this set up on a spare pi one of these days™. You get a free premium acc on the tracking sites, so you can track where tf all those planes and helicopters above your house are going
To report back, my system is up and running. Used my spare odroid xu4 with dietpi for it. Put it all in a case and attached a cheap Nooelec stick. Waiting for my antenna today and to decide where to put it under the roof.
Fine tuning for best reception location will be taking a while to be honest.
I did this for a hot second (already have RTL-SDR set here) but the current location of the RPi is just bad for reception and moving it closer to some window would mean connecting through wifi (can't lay ethernet cables, renting) and that's bad for other services where low response times are preffered/needed (pihole) :(
Instead of connecting it to WiFi, have a look into power line adapters. They route your internet through the copper wiring in your house.
I have a router in my subterranean ground floor linked to a power line adapter, a wired router in my front room a floor up so my PC, TV, Playstation, etc are connected via LAN, and another power line 2 floors above that plugged into another WiFi router running in bridge mode, which supplies WiFi to the top two floors, and another playstation wired in to that router
Basically it means that my ground floor router is hooked to the internet and everything else in the house that needs wiring in is wired in because of the power line, and the WiFi is coming from 2 routers, one on the top floor and one on the ground.
My ISP thought a WiFi router on the ground floor of a 4 storey house was a great idea, but they're stupid. WiFi should be in the highest point of your house.
With a few Power line adapters you can sort your internet out for £25
Vaultwarden is super, but I'd be hesitant to run it on a Raspberry Pi unless I had good backups in place. I've always run stuff off MicroSD cards with Pi's, but I'm sure there's a way to use real drives which would make me feel better.
You don't need permanent backups of it. Vaultwarden is more like a secure "syncthing". I crashed a system with vaultwarden had to rebuild everything but after connecting it to my devices I got the passwords from them back again and nothing was lost.
I ran HA on mine for a while before I moved it to a VM. Right now I'm using my Pi as a secondary wireguard VPN in case my primary is down for some reason.
Also, quick tip, I found that ikea zigbee bulbs work really well but have really bad coil whine when off, don't use them for bedside lighting.
Already got ssd as a nfs share in my openwrt-based router before that I did have it set up on the rpi. I did want to do offsite backup into that disk originally but I've got "only" ~100Mb/s up/down speed here so I didn't want to risk slow-downs etc (but now that you remind me, borgbackup should be rather light on traffic!).
NEMS being a whole OS is a pitty, I like the possibility to have multiple different services there.But you are absolutely right I could have a offsite resource monitoring for my Hetzner setup with these, thanks!
I run a modded Minecraft server for my friends, PiHole for my home network, DDclient, and a discord bot for my discord server on a RPi4 8GB. I also use another as an emulation station.
Immich! It's an amazing self hosted Google Photos replacement.
Zigbee definitely fun with HomeAssistant. I have an SLZB-06M adapter which has PoE (important for me) and is a fairly "open" product (don't need to jump through hoops to flash firmware). I read somewhere that it may offer Thread support at some point but wouldn't count on that.
You can setup a tunnel from your Hetzner VPS to your home with say Netbird and then run stuff that would be a bit to expensive to run on rented hardware. Like say Nextcloud, Matrix or game servers, on your RPi while still having them web accessible thanks to the tunnel.
I rent dedicated machine so the HW I have is the limit - I pay the same rate every month, no matter the usage, so with the bit outdated but still performant Ryzen 5 3600 and 64GB of RAM I was very happy to throw minecraft/zomboid/vallheim servers at it and few more services, aye aye;)
Though the possibility of tunneling services out from the RPi is something I am aware of, but except for stuff that would benefit from video HW accel there isn't much that would be better to run on the RPi instead of on the server directly.
Cool, but I'm guessing that ain't especially cheap right? I pay $60 a year for 4 cores and 8 GB RAM (400 gb storage). Which I consider a pretty OK price. $5 a month.
Ah; then host the OpenVPN server from hetzner, the pi as a client, then configure the server to route traffic out through the pi client into your LAN. Your own little vpn tunnel, instead of using something like cloudflare tunnels.
Use it to make a webcam server. You could probably afford to plug in multiple webcams since it has USB 3. Great for checking on the home when you're away.
Make it into a router and access point. Connect your phone to the AP and use tcpdump to capture packets from your phone for a few minutes. Look through the packets with Wireshark and see how much data is being leaked.
First, you should something decent, not DietPi. You've Armbian for a ready to go experience or official Debian.
Once you get into something Debian 12, you can run LXD/LXC as a containerization / virtualization solution and use the same Pi to run the official HA VM image and whatever else you would like.
Why is dietpi a worse choice? it's still basically debian (11).
I've chosen DietPi because of their sane defaults that I would have to setup myself like vm swappiness, fs noatime, tmp journal, and some more I am not even aware of.
Armbian has sane defaults for SBCs as well (yes log2ram so you won't burn SD cards) and it is way more stable and polished than DietPi with less overhead. About bare Debian, you've the images I linked to and you can make it log to the ram with a simple line in systemd's config.
Storage=
Controls where to store journal data. One of "volatile" (...) If "volatile", journal log data will be stored only in memory, i.e. below the /run/log/journal hierarchy (which is created if needed).