Ask HN: How are you using your Raspberry Pi?

55 points by lenwood 3 years ago | 75 comments

What creative uses have you found for the Raspberry Pi?

ep_jhu 3 years ago |

I'm running a Twitter bot that tweets out sunrise/sunset timelapses, and also does on-device object detection and classification to tweet out helicopters that fly by the field of view.

https://twitter.com/dcskycam/with_replies

It's a Pi 4B with the HQ Cam (6mm lens). The ML models are trained on my MBP, converted to tflite, and run on the pi itself.

The main use case is the timelapses, but after seeing that that most of the helicopters that flew by weren't transmitting ADSB, I figured I could help out the @helicoptersofdc crowdsourcing project (run by someone else) by contributing heli spots in an automated manner that might otherwise go unreported.

I also have a 3B+ running pihole on the LAN.

mindcrime 3 years ago |

Artificial Intelligence research[1]

I also have one dedicated to running the RetroPie[2] distribution and I use it for playing old video games.

I have another with an RTL-SDR dongle[3] attached, and running the OP25[4] software, and I use it as a scanner for listening to local fire/police/ems dispatch channels.

I had given some thought to doing a "cyberdeck"[5] project, but honestly it doesn't have much (if any) practical application, and most of the parts and stuff I bought for that have been repurposed for the "AI box" thing instead.

[1]: https://news.ycombinator.com/item?id=32310799

[2]: https://retropie.org.uk/

[3]: https://www.rtl-sdr.com/

[4]: https://github.com/boatbod/op25

[5]: https://www.reddit.com/r/cyberDeck/

bediger4000 3 years ago |

I've got one of mine collecting weather data

https://github.com/bediger4000/station

I'm hoping to detect the "tide" in the atmosphere with barometric pressure readings, but I haven't done anything towards that.

I'd also like to have an automated way to pick out high/low temperature for the day. I've got 2 thermometers taking temperatures. There's data loss caused by both sensors quitting and operational issues, so I have a lot to learn and figure out in processing the raw data.

mindcrime 3 years ago | |

I wouldn't mind building a weather station at some point as well. It's not something I really need but it would be neat. In conjunction with that, I could also use an RTL-SDR dongle to make a receiver for satellite weather data from various publicly available weather satellites.

The other idea I've toyed with is an automatic plant watering system, in service of my aspiration to start growing my own hot peppers (ghost peppers, habaneros, carolina reapers, etc.)

so I have a lot to learn and figure out in processing the raw data.

If you're interested in weather / environmental "stuff" in a broader sense, you might also be interested in a lot of the other data the USG (and others) make available. NOAA, the USGS, etc. put out all sorts of neat datasets. You can get all the obvious stuff (temp, barometric pressure, etc.) as well as water levels in various creeks and lakes and rivers, discharge volume for same, ground conductivity, stuff about lightning, severe storms (tornados, hurricanes, etc.), wildfires, etc., etc., etc. I'm pretty sure somebody creative could find some really interesting applications for all of that stuff.

bediger4000 3 years ago | | |

DO NOT use a DHT-11 or DHT-22 sensor. Absolute garbage. Spring for the Bosch sensors.

As far as processing the raw data, I'm more interested right now in deciding if I should average which two of the thermometer or barometer readings I've got, and also deciding what to use as a high/low temp for the day - I've had some data dropouts and server crashes where I missed the noon/1pm high temp.

I did get GOES satellite data with a RTL-SDR once a couple of years ago. The antenna is more important than they'd lead you to believe, as is where the antenna is - you pick up a lot of fuzz up to some degrees above the horizon if you place the antenna in an urban setting.

kingcoleman 3 years ago | |

I've got mine collecting dust in a drawer along with a few other impulsive purchases (why did a buy a jar of ferromagnetic fluid again?). I'm a few months into 3d printing I'm seeing the value of using an RPi as a print server to monitor long prints. Now that I see how it could make my life a little easier I'm more motivated to get it set up.

ungawatkt 3 years ago | |

I'm doing something similar on my rpi3, but indoor. A few environment sensors + a basic thermostat script to control my box-fan-in-the-window-plus-smart-plug "HVAC" (not that its been anything interesting as far as control during the summer: ON). Data collection is mostly temp, CO2, and PM since I can somewhat calibrate those, plus pulling down the 24 forecasts from NOAA twice a day, all into a sqlite DB with grafana on top. I'm hoping to get some exterior sensors running as well, maybe off a zero or something smaller, but we'll see.

Bonus points, I can tinker with some probably over-complicated timeseries python classes for sqlite.

piceas 3 years ago | | |

My version is a zero 2 with a humidity sensor controlling a dehumidifier via the tradfri plug. Works great.

Time to first graph was quickest with influxdb for me.

Zerotier and nats.io connect the things.

I want to sprinkle some pico w's around for door/window position monitoring.

harryvederci 3 years ago |

Not creative, I guess, but I use a Raspberry Pi 3 for about 90% of my computing.

It's hilarious to use commandline tools to get a way better and faster experience than with a fancy machine. For example, watching Youtube videos faster, with LoWeRcAsEd titles for videos, and without clickbaity thumbnails, comments, etc.

Having to buy a new machine every X years is ridiculous in this day and age.

PenguinCoder 3 years ago |

I have a raspberry pi Zero W as my garage door opener[1]. Wired into the interior buttons and send relevant signals to an open or close the door. I got tired of replacing batteries in the remotes due to heat/freezing cycles. Hooked up a SignalWire SMS number to a webhook that the PI is listening on. Now I can send an SMS text to the garage door to get it to open.

Have other pi's doing many things, but that's the most creative so far.

[1] https://blog.penguincoder.com/garage-opener-1/

VTimofeenko 3 years ago |

Across the three currently live Pis I have:

* Adblocking DNS on unbound and nsd with policies to serve different results on WG mesh

* Tiny Tiny RSS

* Gitea and Youtrack

* Some home-built apps with Grafana and Postgres

* Homechart

* Wireguard mesh for deployment and on-the-go access to those services

Everything is managed through a Nix flake and deployed through deploy-rs.

Nextcloud, Zabbix and Docspell are running on an old laptop which I plan to migrate to a Pi4 when I can get my hands on it.

cbm-vic-20 3 years ago |

Buried inside a PiDP-11, connected to a VT420. Used mostly for IRC. Though I am considering using it to build a bedside radio/clock/alarm that doesn't report back to FAANG.

https://obsolescence.wixsite.com/obsolescence/pidp-11

electric_dreams 3 years ago | |

How do you know it doesn't report back to FAANG?

cbm-vic-20 3 years ago | | |

Because I will build it and verify the code (either open source or my own) won't report any telemetry to them.

jeffdubin 3 years ago |

Raspberry Pi B: Stream a local ham radio repeater (weather spotters) to Broadcastify

Raspberry Pi Zero: Brachiograph

Raspberry Pi 4B: Octoprint

Raspberry Pi 4B: Home Assistant

Raspberry Pi 4B: NAS (running Kopia as backup target w/ USB HDD, not speed-critical)

Raspberry Pi Zero 2W: ham radio-related software for portable use (e.g. WSJT-X, etc.) using cell phone via WiFi as display/input via RDP

To do: MiniDexed synth module, eInk display driver, network a UPS via NUT, RetroPie, Ham Clock, etc., etc. I've also used them previously as a fax server, digital signage for office lobby, and other things I'm forgetting

PenguinCoder 3 years ago | |

> Raspberry Pi Zero 2W: ham radio-related software for portable use (e.g. WSJT-X, etc.) using cell phone via WiFi as display/input via RDP

I would be interested in a write up about this or hearing more. I let my HAM lapse, but recent got into GMRS. No test required for the license, and way more 'simple'.

jeffdubin 3 years ago | | |

The very basics of it are that I'm trying to operate portable using HF (<30MHz, long range), including for digital comms such as FT8. Typically a computer generates the audio-band signals which are transmitted as RF by the radio. Skipping the laptop (less to carry/power), I've installed a few of these ham apps on the Pi, power it from the radio's battery, and use an adapter (Digirig) to give me serial and audio to the radio. I turn on my phone's hotspot, the Pi connects via WiFi, and I use RDP to remote into the Pi, using my phone as the input and display. The Pi Zero 2W is a little under-powered (mostly needs more RAM), but it does the trick.

The simplicity of GMRS can be good, but for me I rarely use a radio to talk locally on repeaters. I like the idea of communicating as far as possible on very little power (QRP) with a small footprint, and the experimentation angle of it all.

asdff 3 years ago | |

With this many pis, what's stopping you from buying an old workstation that can run all of those systems concurrently?

solarkraft 3 years ago | | |

Management simplicity, probably. There are many pre-made images you can just flash on an SD card and have run perfectly. Computationally you could very likely run all of the services on a single Pi just as well.

jeffdubin 3 years ago | | |

Most of these live in different locations, or are portable.

l72 3 years ago |

I have one hooked up to a TV in my front room that gives me weather and live ETAs and visualization of the bus stops near my house:

https://blog.line72.net/2019/08/02/announcing-realtime-bus-t...

l72 3 years ago | |

I also have a very old pi hooked up to my other TV that is non-networked, and just plays random futurama (Original run only) episodes. No need to decide what to watch, my TV only plays futurama :)

khadgar25 3 years ago |

I'm running a Roon end point using RoPieee OS[1] which is connected to my DAC and amplifier. This also allows me to do Airplay or drop any streams on it so I can listen to it either on headphones or speakers connected.

[1]: https://ropieee.org/

indigodaddy 3 years ago |

PiMiga! https://youtu.be/KLJk8fTjQLw

Also Combian 64 is very cool https://cmaiolino.wordpress.com/

gsora 3 years ago |

I am lucky enough to have four Pi's, although only three of them are actively used:

- a Pi 4 8GB which runs Home Assistant along with Zigbee bridge, and PiHole - a Pi 4 4GB used to debug/flash my Precursor[1] - a Pi 3A+ currently in search of a use-case, after being used for a university research project - a Pi Zero 2WH for Pwnagotchi :-)

I was able to snatch the Pi 4 4GB and the Zero 2WH at very good prices by connecting the excellent RPILocator[2] to IFTTT (not sponsored :-)

[1]: https://betrusted.io/ [2]: https://rpilocator.com/

vintermann 3 years ago |

I won mine in a quiz competition, so I didn't have any special project thought out for it beforehand. I ended up using it as a piano synth: running Pianoteq and hooking it up to a digital piano, it gives much better sound than the digital piano's built in sound (and far more flexibility).

I was worried about latency, and that I would have to overclock it (the guides I read on the net suggested I would have to). Latency was a problem in the start, when using the Pi's built in audio jack, but once I switched to an external sound card the latency vanished. Didn't even have to overclock it, though I added a couple of cooling ribs just in case.

mindcrime 3 years ago | |

Yeah, the RPi is known for having a somewhat crappy built-in audio adapter. I was doing some stuff with speech synthesis using espeak-ng, and using the built in interface it was basically unusable. Now to be fair, the espeak-ng voices aren't that great to begin with... but they're usable on decent hardware! I switched to an external USB sound card and that made a dramatic difference. It's back to where the default English voice sounds kinda like WOPR from War Games, and some of the mbrola voices actually sound reasonable.

bjoli 3 years ago |

Printer server for turning a dumb printer into a network printer.

Sensor and pump control for a self-watering flower bed.

I used to run a server with my unifi controller, NAS gateway, and IRC server, but I found an old office PC that does that for me now with about 10x the performance.

jdwhite 3 years ago |

- Pi 4 to relay data from 433/915MHz weather station/temp/humidity sensors to MQTT using three SDRs and RTL_433 (consumed by Home Assistant, but could be read my anything subscribed to MQTT topic). One SDR for each 433/915MHz and a third that cycles between scanning 315, 345, and 868MHz every half hour.

- Two Pi 4s used as secondary DNS servers (with RPZ for blocking crap like Pi-Hole but using ISC BIND) for home network (fed from hidden primary).

- Pi 4 as a Linux workstation

- Pi 2 as a proxy between my solar inverter and WAN to intercept/decrypt traffic containing panel optimizer data not available from API

- Pi Zero W as serial console server.

solarkraft 3 years ago |

Not doing this yet for lack of a Pi 4 (or other SBC with USB 3.0), but I plan to build a simple and reasonably performant NAS with one and USB SSDs.

I've considered PCIe -> SATA adapters, the boards that do this nicely aren't available - Radxa Taco, Wiretrustee SATA board - or have too few slots - PiBox- and the performance gain, about 30%, doesn't seem worth it when accessed via the network anyway. Of course I'd love to be corrected (hey Jeff).

ksaj 3 years ago |

I use mine mostly for educational pursuits. For example, I have a clusterHAT with a bunch of Zeros on it, which I used to learn MPI.

I also use a pi as a home central server, and other pis for related things around that.

I actually love using the Pi4 with 8G RAM as a desktop with two monitors. I'm not a gamer, so I don't feel any lag.

Lately I've been re-learning a lot of my old electronics project material with the newer Pi Pico microcontroller. I'm actually putting a larger project together with it, that will hopefully go online and not just be for myself.

randomopining 3 years ago | |

Does it actually work as a desktop? I heard it can't even play youtube vids witout lag

ksaj 3 years ago | | |

Sorry, I missed this. Hopefully you'll see my reply.

Lag certainly was a problem for me with earlier pi models as well. The Raspberry Pi 4 doesn't have the lags, or at least I don't experience any. It's actually smoother than my laptop with YouTube videos. And it's quite fine with both hdmi ports in use. Probably not multiple videos at one time, of course.

alphanumeric0 3 years ago |

I created a little DIY web-based dashboard that displays on my TV. I have a tiny bit of Python that runs on startup that turns on my TV via an API, then launches Chromium in kiosk mode and loads my webpage written in Elm.

I have nicely tiled widgets with CSS grid that displays real-time bus arrivals and current hourly weather forecast. I'm going to add live streams from my IP cameras around my place. Some kind of calendar widget would be nice too, to remind me of important events at a glance.

achairapart 3 years ago |

If only I could find ~30 Raspberry Pi4, I'd use them for a digital signage system. (For availability tips or suggestions, I would be very grateful!)

awiesenhofer 3 years ago | |

If its just digital signage why not use RPi3s?

achairapart 3 years ago | | |

Mostly because software was designed as a burnable ISO image tailored to Pi4 specs. I could also make a Pi3 version, but availability looks quite the same if not worse.

mercwear 3 years ago |

Learning. Right now I have my Pi running a Python script that will grab messages placed in an AWS SQS queue and scroll them across an LCD screen attached to the Pi via breadboard.

For me, projects like this make learning something I am not all that interested in but required to use for work (in this case SQS) much more fun because I get to learn something that interests me (in this case getting an LCD screen to work with the Pi)

swapsCAPS 3 years ago |

One running LibreElec and one as a web server running my Amsterdam ferry app https://pont.app. But the most “creative” has got to be the one that measures IAQ and CO2 in my office. It also runs Prometheus and Grafana as a front end. Custom 3D printed case for the sensors which are attached with embedded magnets.

jamesu 3 years ago |

Using a 4 as a wireless bridge. I've tried using them to host servers (mainly storing data) but been burned too many times using sd cards, and once I inevitably add in an ssd/hdd the value of using the pi vs just getting a cheap significantly more powerful x86 system starts to dwindle. Would love to come up with a project that makes good use of the GPIO pins though.

VTimofeenko 3 years ago | |

Recent-ish firmware allows to boot Pi from USB, which IME have been much more durable than sd cards

FlipEnergy 3 years ago |

I have a super old pi 1b connected to a small screen that just randomly plays Conway's game of life every couple of minutes.

daltont 3 years ago |

I have two Pi Zero/W with hard drives connected to them. I scp video files to them. I wrote https://github.com/daltontf/omxserver to allow those files to be played back via a web interface.

NoZZz 3 years ago |

I have a pi zero functioning as a doorbell (with camera & opencv) One pi 3 running moonlight to stream my win10 desktop (with gaming!) over ethernet to my living room tv. One pi 3 running a display in the hallway. (purpose: grafana/ip cam views/etc) One pi 3 operating a cnc machine (octoprint etc).

sandreas 3 years ago |

I use it as a media player for my daily workout (I used DVDs before) :-)

https://pilabor.com/series/raspberry-pi/media-player-with-li...

WillAdams 3 years ago |

Not particularly creative, but I have two in use (both rPi 4s):

- running Carbide Motion to control a CNC - running a backup of a wiki and forum which was taken off-line so that I can refer to it

I really should set up a media/file server and work up a suitable backup strategy.

random_0 3 years ago |

I'm using pi's for these works: 1. A pi 4B running jellyfin and aria2c. I use aria to download files, torrents and stream them on jellyfin. I have a aria2 web frontend for using it from browsers. 2. A pi zero wh running pihole. 3. Another pi zero wh for nginx

hidden-spyder 3 years ago | |

Can you explain the first usecase in more detail to me? I don't understand what's different in it compared to normal downloading.

random_0 3 years ago | | |

aria is a comandline download utility. Link: https://aria2.github.io/ Basically it's like idm which downloads files faster than your browsers.

azalemeth 3 years ago |

With the digital TV hat and Kodi, it's a fantastic smart TV that has the huge advantage of not actually being a smart TV. Also, TV headend lets you stream TV or Radio to any computer you want -- it's amazingly fast and quite low bandwidth.

herbst 3 years ago | |

For whatever reason I only had problems with Kodi on a Pi. Crashing, slow, ... Using it as app within an android stick now without bigger issues.

Pi 4+ with case was about $100, the stick only $40

atmosx 3 years ago | | |

I run openELEC on a RPi3 without issues, apart from the fact that pushing large files to the Pi is really slow (3-5 MB/s).

ReaLNero 3 years ago |

Comment here if you're interested in learning more, but: I made an app that periodically checks the US embassy website for visa appointments and got my family a trip to my graduation just because of it!

brendanfalk 3 years ago | |

Interested!

teejmya 3 years ago |

I have a 4 by my wireless router doing DHCP, Pi-Hole DNS ad-blocking, and hosting a Wireguard tunnel.

I bought a nice case and M.2 SSD for it, and it has been running happily for almost two years.

woopwoop24 3 years ago |

i am using mine as gateways into my networks. All deployed with wireguard and traefik and authelia to let me login to anything with 2fa if i want it exposed, got tired of the very bad solutions some companies like synology provides with 2fa and dyndns.

no firewall ports just plug it in and ready to go in a second, and i use ssd's instead of sd cards for speed and reliability. Works without thinking about it for at least 1 year now.

Havoc 3 years ago |

I've got 3 of them for learning kubernetes. Another is collecting ADS-B data, and one is a backup pihole when the main server is rebooting / offline

earleybird 3 years ago |

one for each of the following

- Pihole

- Apache, subversion (proxied through Traefik on a 3 node x64 Docker Swarm cluster)

- NodeRed, MQTT (ESP8266 temp / humidity probes various locations around the house, running since 2017)

- OctoPrint for PrintrBot (3D printer circa 2015)

- OctoPrint, Klipper for Ender 3

Also, a 4 node K3s cluster each with 400gb ssd and 2Tb seagate managed by Longhorn

apparently I don't know when to stop :-)

atommclain 3 years ago |

Past:

* Kiwix server hosting Wikipedia offline among other info

* RetroPie

Present:

* Home Assistant (home automation)

* Zigbee2MQTT (non-propriety home automation hub)

* Pi-hole (ad blocker via dns)

Future(?):

* WireGuard VPN

* Micro weather station reporting

* FlightAware station (tracking Airplanes flying nearby)

dzikimarian 3 years ago |

Ha, nextcloud, wireguard, miniflux. All on single Pi 4B, booted from SSD. Honestly I'm surprised how much can it lift.

baremetal 3 years ago |

Still trying to find one to buy to replace the one that died. But they are out everywhere every time i check

kd913 3 years ago |

I am using multiple 4bs for WireGuard + pihole and cloudflare to setup my own global vpn.

polski-g 3 years ago |

I'm using it as an entry in my shopping cart, waiting for them to come back in stock

mindcrime 3 years ago | |

If you live within driving distance of a Microcenter store, it seems like they've had a modest amount of success in acquiring stock here and there. I haven't heard a lot of reports of people getting any anywhere else lately. I managed to score 1 8G model from Elektor earlier in the year, but haven't heard any news about them getting any more in since. :-(

schwartzworld 3 years ago |

I host my web projects on a pi 4 using a reverse ssh tunnel to a $5 linode box.

jethronethro 3 years ago |

Y'know, I still don't own a Pi. And I feel really guilty about it ...

mindcrime 3 years ago | |

Sadly now is not the best time to get started, as Pi prices and availability are in a Bad Place due to the Chipageddon[1] situation.

[1]: https://www.theguardian.com/books/2021/aug/27/chipageddon-ho...

blockwriter 3 years ago | | |

I don't know if I got lucky or not, but I went into a MicroCenter, because I burnt the RPi 4 I was using for a hobby project and they had the RPi 400 kit in stock. They somehow had one loose RPi 4 2GB. MicroCenter will only sell them in store, it seems.

jethronethro 3 years ago | | |

Sometimes, procrastinating can be a good thing :-)

visiblink 3 years ago |

My Zero W hosts a gopher site and an 'unfederated' email service.

type0 3 years ago |

one of the most popular use cases: as a dust collector in a drawer /s

jmkjaer 3 years ago | |

I have mine on a shelf. When visitors ask me what it is, I tell them about all the awesome things you can do with it. It's great until they ask me what I use it for currently.

galleywest200 3 years ago |

Used one for quite some time as a Samba share and Plex server for music.

dav43 3 years ago |

pi4B: Nextdns client, tailscale, shared network drive, log aggregator for other devices on my network and also data end point for some iOS Apps (Overland GPS tracker)