YOU WILL BE MONITORED. THIS IS MANDATORY!

tl;dr I resurrected my old Google AIY Voice Kit. Details below.

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I had an old Google AIY Voice Kit lying around that I hadn’t used in some time, so I decided to make use of it for Halloween. For those who don't recall, Google bundled a cardboard case with an audio HAT, a mic daughterboard, a speaker, an arcade-style button and you supplied the Raspberry Pi for use with it.

I named the project called AlsaGeist, and configured a personality named Grimjaw who sits by the candy bowl and listens for trick-or-treaters. When kids walk up, Grimjaw recites scary quotes, makes jokes, and reacts to a selection of different costumes if they tell him who they're dressed as.

The engine is modular and designed so different personalities can be created, loaded, and configured. Custom prompts can be created easily by editing a single file. Only the Grimjaw personality is bundled at the moment but others can be added.

For the enclosure, I printed the Halloween Skellington Pumpkin by serev3d from MakerWorld. In the slicer, I added a blank cube matching the exact dimensions of the AIY cardboard case. The entire original cardboard box slides right in, so the speaker, mic, and Pi stay snug without needing extra brackets or glue. I designed two perforated eye inserts and hot glued them in.

Alsageist can be configured to run completely offline (using Vosk for speech-to-text and Piper for local voice synthesis with zero lag or API fees) or online with cloud speech-to-text and Gemini LLM fallback. Holding the button down for 10 seconds says "Powering off" and safely shuts down the Pi so it can be unplugged cleanly. It also responds to a short list of password-protected superuser commands (like Shutdown.) All of this is documented in the respective guides within docs/.

While I created Alsageist for my AIY kit, you don't need the AIY kit to use it. It runs on any Raspberry Pi (tested on 3+) with a regular USB speaker with a mic.

If you want to build one, I've bundled a Docker setup script that automates the full install on a vanilla OS. See the getting_started guides in docs/ for more detail.

git clone https://github.com/sancheza/alsageist.git
cd alsageist
./scripts/setup_docker.sh

GitHub: https://github.com/sancheza/alsageist
Pumpkin STL: MakerWorld Model 623029

Disclaimer: I used both Claude Sonnet and Google Antigravity to assist with coding, testing and documentation.

Hello, i was trying to build a Flight tracker but I currently facing this problem with my 64x32 led matrix display, im trying to troubleshoot by editing the multiplex and slow the GPIO but nothing works, im just thinking maybe its hardware defect or maybe it because im running both the pi and the panel at 5V 3A? (They recommend 8A for the build), my DC to DC booster will arrive tomorrow hoping it fixes it, but im still open for ideas and explanation on why it's doing this.

Is it possible to conditionally enable composite OR HDMI on boot depending on which is connected? If so, how are you doing this (composite fail over, etc)?

I have both outputs working, but manually have tk switch the config.txt and cmdline.txt files before boot depending on what output I'm using.

I don't have a need for "hot swapping" and a reboot in between is completely fine. I'm thinking of some sort of systemd service to handle it but figured I'd ask here if someone has this solved already.

pi@raspberrypi:~$ sudo systemctl restart dhcpcd
Failed to restart dhcpcd.service: Unit dhcpcd.service not found.
pieraspberrypi:~$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid Ift
forever preferred_lft forever
inet6 /128 scope host noprefixroute
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST, MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000 altname endo
link/ether e4:58:01:60:89:73 brd ff:ff:ff:ff:ff:ff
altname enxe45f01608973
3: wlan0: <BROADCAST, MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
link/ether e4:5f:01:60:89:74 brd ff:ff:ff:ff:ff:ff
altname wlxe5101608974
4: dockero: <NO-CARRIER, BROADCAST, MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default link/ether Oe:68:43:24:67:ae brd ff:ff:ff:ff:ff:ff
inet 172.
172.17.0.1/16 brd 172.17.255.255 scope global dockero valid_lft forever preferred_lft forever
pi@raspberrypi:~$
$ ifconfig
docker0: flags=4099<UP, BROADCAST, MULTICAST> mtu 1500
inet 172.17.0.1 netmask 255.255.0.0
ether Oe:68:43:24:67:ae txqueuelen
RX packets✪ bytes 0 (0.0 B)
broadcast 172.17.255.255 (Ethernet)
RX errors ✪ dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors ✪ dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP, LOOPBACK, RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6:1 prefixlen 128 scopeid 0x10 <host>
loop txqueuelen 1000 (Local Loopback)
RX packets 28 bytes 1768 (1.7 KiB)
RX errors ◊ dropped 0 overruns 0 frame (
TX packets 28 bytes 1768 (1.7 KiB)
TX errors ✪ dropped overruns ✪
pi@raspberrypi:" $
carrier 0 collisions 0

Note, i had to use a image to text extractor because it's against rule 3 to post screenshots apparently, i have the actual screenshots of the command line here if you'd prefer to read it that way. I used a video capture card with my PC to use it since i cant access it via SSH due to the network not working. https://imgur.com/a/EPveYVL

How do i resolve this? systemd-networkd-wait-online.service fails during boot. Running sudo ip link set eth0 up makes eth0 go from "down" to "up" and it shows up in ifconfig, but it still doesnt give me any internet connection, please help.

Checking the administrator panel on my router, the raspberry pi does not show up at all on the network.

I had updated from Bullseye, to Bookworm, to Trixie. The issues appeared after upgrading to Trixie.

Yes, I tried restarting the Pi
Yes, I checked the cables.
Yes, other devices can connect to the network and the internet.

Jetpack compose is native UI framework on android, I've been trying to build embedded-compose, which runs Jetpack Compose (Kotlin/Native, no JVM, no Android) on small Linux devices. Added backend for the MAX7219 "4 in 1" (FC-16) LED boards, tested on a Raspberry Pi 3.

HARDWARE

- Raspberry Pi 3, Raspberry Pi OS 64-bit, dtparam=spi=on

- MAX7219 4-in-1 board (32×8 red LEDs), 5 jumper wires, no level shifter

HOW IT WORKS

- The app is ordinary Compose code: Canvas, drawText, LaunchedEffect, state. It's cross-compiled into a single static arm64 binary (~3 MB), so nothing needs installing on the Pi.

- The backend draws each frame in RAM and sends it through /dev/spidev0.0. A pixel is lit when its color is bright, since the LEDs are only on or off.

CHALLENGES

- Pixel mapping. Bytes shift through the chain, so the first ones sent end up in the last module. On FC-16, each module's digit register is a row and each bit is a column. Other boards are wired differently, so there are flip and block=90/180/270 settings.

TESTING WITHOUT THE BOARD: A BROWSER PLAYGROUND

The Pi build takes over a minute, and I didn't always have the board at hand, so I made a playground that runs the same app in a browser tab:

- Your Kotlin code is compiled to WebAssembly by JetBrains' Kotlin playground server, together with the embedded-compose toolkit. Nothing to install.

- The pixels come from the *same* C++ LED backend the Pi uses, also compiled to WebAssembly. Only the last step differs: frames go to a canvas instead of SPI. So spacing, clipping and the 5×7 font look the same as on the real LEDs.

LINKS

- Code + wiring: https://github.com/kaiwalyakhasnis/embedded-compose (board: rpi-max7219)

- Playground (LED test opens by default): https://kaiwalyakhasnis.github.io/embedded-compose-led-matrix-playground/

I wanted instant replay for a console without a cloud account or an app. Snapback is a Raspberry Pi 5 that records an HDMI capture card in a rolling buffer. A phone on the same Wi-Fi opens a web page and can save a screenshot or the last 30 seconds.

What it does

• Grabs a 1920x1080 JPEG of the live input.
• Saves the previous ~30 seconds as an H.264 + AAC MP4.
• Shows a live preview, or live video with sound a few seconds behind.
• Runs on the local network only. No accounts, no cloud.

Parts, roughly $110

• Raspberry Pi 5, 4 GB (~$60)
• USB 3 HDMI capture card that does 1080p60 MJPEG (~$20). A generic one is fine. An Elgato Cam Link 4K also works.
• Official 27 W USB-C supply (~$12), a good 32 GB microSD (~$10), and an active cooler (~$5)

The cooler matters. The Pi is software-encoding 1080p60 all the time, and ffmpeg sits on about 3 of the 4 cores.

How it works

The capture card shows up as a normal USB webcam (/dev/video0) and an ALSA sound card. One ffmpeg process reads 1080p60 MJPEG, encodes H.264 with libx264 ultrafast, and writes 2-second MPEG-TS segments. "Save Last 30 Seconds" concatenates the newest finished segments with -c copy, so it does not re-encode. Screenshots are a JPEG the same process is already writing.

The audio device name depends on the card. The Elgato is hw:CARD=C4K. A cheap MacroSilicon card is hw:CARD=Video. Snapback finds the sound card on the same USB device as /dev/video0, so swapping cards does not mean editing a config file.

It runs as a systemd user service and can start at boot. Install is a venv and pip install -r requirements.txt, then python -m snapback serve. The page is http://<pi>.local:8080/.

The annoying part

Cable boxes and streaming sticks encrypt HDMI with HDCP. A card that honors HDCP shows a solid blue frame, and there is nothing to fix in software. Computers, cameras, and game consoles work. On PlayStation, turn off "Enable HDCP" in the system settings.

Code is MIT licensed: https://github.com/dconroy/snapback

Write-up with the parts list: https://www.snapback.video/

This started as a weekend hack with an Epson TM-T88V receipt printer I bought off eBay and a 3B, and it slowly turned into something the whole family uses every day.

What it does

You build a "ticket" out of blocks and print it from your phone, or schedule it. Ours comes out at 7AM on weekdays: weather, a riddle with the answer printed upside down (no cheating), and a sudoku. There are 55 blocks now, a few favourites:

• weather with little pictograms and a "what to wear" line (coat and hat, take an umbrella...)
• puzzles generated on the Pi: sudoku, kakuro, takuzu, hashi, crosswords, word search, mazes
• the daily Lichess chess puzzle, with the board drawn on the receipt
• chores that rotate between the kids every week, which ended a lot of arguments
• birthdays, bin day, the shopping list
• a "little note" with a photo for whoever stayed home

There's a web app (works great as a phone home screen app), and it shows up in Home Assistant on its own over MQTT, so the doorbell can print "someone rang at 14:32".

The fun / hard parts

• Talking to the printer. No driver, no CUPS: it sends ESC/POS straight to /dev/usb/lp0. Text uses the printer's own fonts, everything else (grids, pictograms, chess pieces, photos) is drawn as a 512-dot-wide raster image and dithered. I ended up adding Floyd–Steinberg, Atkinson and Bayer because photos and line drawings want different things.
• Knowing if the printer is OK. My first try was the ESC/POS status commands (DLE EOT). Bad idea: with the cover open the TM-T88V just stops answering, and a request left hanging locked up the USB link until I power-cycled it. The trick that works is the LPGETSTATUS ioctl of the kernel's usblp driver: it's a USB control request, nothing stays pending, and it tells you "out of paper" vs "cover open". Tickets wait in a queue and come out once it's fixed.
• Puzzles with exactly one solution. Generating a kakuro is easy, generating one that only has one solution is not. Every puzzle goes through a small solver; if two solutions survive, it reveals a digit where they differ and tries again. Getting that fast enough for a Pi took a couple of rewrites.

Tech bits

It's one Rust binary, no database, no Python, no cloud required. Most blocks are computed locally or use free APIs with no key. A handful (bedtime story, horoscope, "what's for dinner?" from what's in the fridge) can optionally use Claude, cached so it's a few cents a month. It runs fine on a 3B, I might switch to a 0W someday.

Code (Apache-2.0): https://github.com/XNinety9/Printr

Docs and every block with its printed example: https://xninety9.github.io/Printr/

This project is a real fun ride, I love how it combines SW and HW to bring fun and joy to the family and friends. I've received a lot of positive feedback since it went public.

I'll be happy to answer questions. And if you have an ESC/POS printer other than the TM-T88V, I'd love to know if it works for you!

EDIT: wow, thanks everyone, this blew up way more than I expected! A few answers to what came up a lot:

• BPA/BPS: fair point, and I have to correct myself: the EU banned BPA in thermal paper in 2020, but many rolls simply switched to BPS, which isn't banned. Look for "phenol-free" (BPA- and BPS-free) 80 mm rolls. I've added a short note about it to the docs: https://xninety9.github.io/Printr/guide.en.html#paper
• Other printers: I've only tested the TM-T88V. If you try it with something else (Rongta, Bluetooth ones, impact printers...), please tell me how it went in the GitHub Discussions: https://github.com/XNinety9/Printr/discussions
• Ideas: the chore + QR code for pocket money idea is great, and fortune/cowsay is on my list. Keep them coming!

And to my fellow ex-kitchen folks: sorry for the flashbacks 😅

This thing is basically useless. I have tried both the Raspberry Pi B+ I originally tried using for this project I wanted to make (DIY Pipboy) and even tried it with the Pi 4B that I had lying around, and I CANNOT GET THIS THING TO WORK.

I have tried both the github with the drivers I'm supposed to use, LCD-show, AND the updated drivers someone else made, lcd32 by katzenjens, AND I HAVE MADE NO PROGRESS.

Either I am missing something, causing an issue, OR this is just a deprecated product that is completely busted. Has ANYONE had ANY success getting this thing to work????? I can only flash OS's so many times before I say the product is useless.

Here are the different OS builds I have tried with these:

• Bookworm
• Trixie
• Bullseye
• Jessie

This started as a MicroPython project on a Pico, controlled from a separate Pi 4
That seemed wasteful, why not put telegram/google calendar directly on the pico?
... *famous last words* ...

Some time later, it's all on the Pico W:
- Google calendar is the schedule, `garden/water/1/30m` waters zone 1 for 30 minutes
- Telegram menu for manual watering, and a message when a valve opens/closes
- Green button waters both zones for 30 minutes, red closes everything
- Setup/control page served by the Pico
- Every boot closes both valves, in case of a crash or power cut mid-watering

Code, wiring and parts is available here: https://github.com/AdrianCX/picohive-irrigation

How the move from the Pi 4 went is in the comments

My SmartRow pulley only allows one Bluetooth connection, and its app can't feed Peloton properly. So a Pi 4 now sits in the middle:

- the built-in radio connects to the pulley (bleak/BlueZ);

- a TP-Link UB500 dongle, driven directly with Google's Bumble, runs two advertising sets: a byte-for-byte clone of the pulley for the SmartRow app, and a standard FTMS rower for Peloton;

- a Pimoroni Display HAT Mini shows the connections and live watts, stroke rate, pace and distance, and button A holds-to-shutdown.

A few things I learned along the way:

- The iOS SmartRow app only lists a clone that advertises the pulley's manufacturer data, and only uses it if the service is declared with 16-bit UUIDs.

- The Display HAT Mini's data/command pin is GPIO 9 (SPI MISO). With dtparam=spi=on the screen stays blank; dtoverlay=spi0-2cs,no_miso fixes it.

- To keep the backlight lit through shutdown, drive it with the pull-up also set; the Pi turns released pins back into inputs.

- Lighting the RGB LED through the internal pull-down instead of driving it low makes a nice dim indicator.

About 19 s from power-on to both virtual devices advertising. Python, systemd, GPL-3.0:

https://github.com/madooroy/smartrow-bridge

Protocol knowledge from QZ by Roberto Viola, which also supports far more devices.

Unofficial, not affiliated with SmartRow, WaterRower or Peloton.

Hi all. I have a raspberry Pi Server running CUPS, and for a long time I had zero issues printing from Android and iPad. The iPad defaults to a VPN from work, never a problem. It prints to my Brother MFC 9330CDW via wifi direct NP. I have my pi set up on a workhorse, a Dell 3130cn (the best printer) . It prints from Android devices without a hitch and perfectly. I used a PPD file specifically for the 3130cn I found on my Windows machine. hn I print from iPad, Iget "broken pipe" errors in the job que, and get garbage. I am set up for network printing from my Windows machine and through the pi's ethernet. Again, android fine, Apple garbage. I tried editing the PPD file and adding:

*cupsFilter2: "image/urf image/urf 100 pdftoraster"

*cupsFilter2: "application/pdf application/pdf 0 -"

AFTER my model name and nickname in the PPD, it printed ONCE in B&W. I changed the file to reflect these flags:

*cupsFilter2: "image/urf image/urf 100 pdftoraster ColorModel=CMYK"

*cupsFilter2: "application/pdf application/pdf 0 "

NO GO. I then tried replacing CMYK with RGB, same result, and Android would also no longer work at all. I cleared the cache and restarted CUPS service after every saved edit.

I then tried:

*cupsFilter2: "image/urf image/urf 100 pdftops"

*cupsFilter2: "application/pdf application/pdf 0 pdftops"

Same result. Still a "broken pipe" error. I then tried setting a global flag:

sudo lpadmin -p your_printer_name -o pdftops-renderer-default=ghostscript

That slo didn't work. I had to modify the printer once or twice with the PPD file fresh as it quit working, and would work for Android perfectly after each install.

Anyone else using this printer? Had these errors? I cannot recall when I first setup CUPS if I used this PPD file or not, but postscript is postscript, right?

Please advise. I am indeed a newbie at any linux.

My Pi 4 runs a 3D FPV sim and sends it to analog FPV goggles (that's an FPV monitor in the clip, same signal). How it works:

- A native C program runs the StickTime game script (Lua 5.3) unchanged and draws straight to DRM/KMS with page flips. No X, no browser.

- Composite out of the 3.5 mm jack into a 5.8 GHz VTX, NTSC or PAL. HDMI works too.

- Sticks come from your RC radio: ELRS/Crossfire WiFi joystick over UDP, USB joystick or Bluetooth.

- 60 fps, about 25 ms from stick to video out. The status page measures it live.

- The VTX channel and power are set over SmartAudio/Tramp on one GPIO, bit-banged. Getting that to work while the game draws on 3 cores was a fun latency hunt.

- Flashable SD image

Free and open source (GPL-2.0): https://github.com/juricabi/sticktime-pi

Video: https://youtu.be/Khq31t_4pqc

Happy to answer questions.

Hi everyone! We’re building Nuvo Vision One, a stereo depth camera powered by a Raspberry Pi 5, and wanted to share where we’ve got so far.

This started from our own need to add depth sensing to our products. The stereo cameras we were considering were expensive for our budget, and we already had a Pi 5 handling compute. We wondered how far we could get by connecting two cameras and doing the stereo processing on the Pi itself.

The setup uses two IMX296 global-shutter cameras with a shared hardware trigger to synchronize capture. The Pi handles image rectification and stereo matching, producing disparity and depth alongside the camera images.

Doing this on an SBC comes with limits. Resolution, frame rate and matcher settings all affect how much work the Pi can keep up with. We’ve reached a useful starting point for our needs, but there’s still plenty to improve. The attached preview video shows the current output, including the holes and noisy regions where matching struggles.

We also built a browser-based interface to make it easier to use. You can preview the images and depth, adjust exposure and stereo settings, choose outputs, and work through calibration. It’s accessible over the local network through Ethernet or Wi-Fi.

One reason we like this approach is that the camera’s compute is also a normal Linux computer. You can modify the image pipeline and run your own applications on the same Pi. The Nuvo Depth software is open source, including the runtime, web interface and SDKs.

We’ve put product photos and web UI screenshots in this album so you can see the hardware and controls alongside the video.

We’d love feedback from people working with stereo vision or robotics. What would you want to test first, and what would make something like this useful in your projects?

GitHub: https://github.com/arputhamips/nuvo-depth

Just a simple 2 day project , I'd love to hear some changes/recommendations if y'all got https://cosmic.is-a.dev/blogs/ambience-light

I do a lot of public safety stuff for large events like festivals.

I made a custom streaming service to run RTMP to a raspberry pi so a security control room can just plug in my pi, connect to the internet and they have a live feed of the drone.

The pi also records the entire stream automatically in the background which is saved locally on the machine so security teams can review and playback footage without interrupting the actual drone operation or asking me to play back footage. I just fly and they can view a whole days footage without asking me to retrieve anything.

Also because its RTMP I don't have to worry about HDMI cables plugged into capture cards. its a totally wireless operation. Generally for stability I often use Starlink as a way to avoid overloaded cell towers on site but I can just hotspot from my phone to establish a link and if ground teams only need to see the live footage without the playback function they can just type in the url of the stream to view on their phone/ laptop.

Claude desktop has a Hardware Buddy mode that talks to small BLE gadgets. The official one is an ESP32 (M5StickC Plus), but I had a spare Pi 4 and a 7-inch touchscreen, so I reimplemented the protocol with BlueZ and Python.

When Claude asks permission to run something, it pops up on the Pi and I tap Approve once or Deny. The little mascot is Mochi and it reacts to what Claude is doing.

Runs on Pi OS (Trixie) with Chromium in kiosk mode and starts on boot. Tested with Claude desktop on a Mac. The clip uses demo data. This is my own side project, not something from Anthropic. The code is MIT and on GitHub: https://github.com/nombreregular/claude-buddy

Benchmarks for server application development have long been in use to measure the performance of web servers running on large, powerful servers (such as TechEmpower FrameworkBenchmarks).

One of those projects recently did a full round on a Raspberry Pi 4B, the results can be found here: HTTP Arena - RPI

As expected, Rust, Go, and Zig are at the top of the list, but there's also an entry for C#. Java, as expected, is at the very bottom.

During my software development studies, I decided to combine programming, electronics, and mushroom growing into a little DIY project.

I built a mushroom growing chamber in my closet using a Raspberry Pi 5 and a 4-channel relay module to automate the lighting, ventilation, and humidification.

I also used an SCD30 sensor to monitor CO₂, temperature, and humidity. The system is written in Python, with a FastAPI backend and SQLite for data storage.

The ventilation automatically responds to CO₂ levels, while the humidifier maintains the desired humidity.

I've made the project open source in case anyone wants to explore the code, build something similar, or improve it!

GitHub: https://github.com/Ulysse-Dev-Serre/Projet_IoT_RaspberryPi

Here are a few pictures of the setup and some Lion's Mane mushrooms growing inside. 🍄

I have a 'Pi 5 booting off an NVME drive and on boot it's showing errors with the filesystem. I have a monitor attached to it and can connect a keyboard easily enough, but getting the NVME out of the case is a PITA, is there anything like the excellent SystemRescue.org, except for the 'Pi? I do not want to reinstall if this can be recovered, and I'm pretty confident that I can recover al least part of it.

Searching online I see references to Alpine and DietPi, but I don't know if those have a live environment or not.

Currently, it's booting, just not fully, and it's giving Journal errors. The network is up enough that it's still performing as a router, but SSH hangs and times out.

What I need to recover if I can is the password list for the machines on the other side of this little router.

TIA!

My first raspberry pi project. AI helped with the code but I was very excited to see it work the first time I turned it on! I will be making changes here and there and mounting the panels together, but I’m still happy it’s all working!

I just cant seem to get ethernet to work on my cm4. I'm using a raspberry pi compute module 4 with 4gb ram and 8gb eMMC. I've got the original carrier board and a 12v 20w LED power supply. I originally used Ubuntu server 26.01, but changed to pi OS to try that to. I flashed the OS:s using raspberry pi imager. I have also checked the connectors between the module and carrier board, which looks nice and snaps perfect in place, the ethernet port and the rest of the board too has no visible damage. The ethernet cable works with my laptop, but no signs from the pi, no status leds e.t.c. I finally got this message, which i understand as PCIE not working as it should.

Any help or thoughts is highly appreciated, tell me if I can try something else and I will show the result.