IcedRaktajino

By popular demand from this post, here's the write-up for my version of that travel server.

The travel server is shown with the, currently, bare 5V UPS board to its right. One day I hope to have a 3D printed case for both of those, but they're currently separate as my 3D modeling skills are basically non-existent. The power cable is wrapped in aluminum foil and then wrapped in electrical tape due to EMI from the wifi adapter causing random glitches. A ferrite bead would probably solve that more elegantly, but I didn't have any on hand so made due with what I have.

Hardware

• Banana Pi M4 Zero
  • 1.5 GHz Quad Core ARM64
  • 4 GB RAM
  • 32 GB eMMC
  • 1 TB Samsung PRO Plus SD Card (bought before prices went nuts)
• Li-2B UPS Board + 2x 3,000 mAh 18650 batteries
• USB-C to USB-A 90 degree angle adapter
• USB Nano Wifi adapter

Note: Unlike the Pi Zero, these have two USB ports. One is configured in host mode and the other in peripheral mode.

Features and Capabilities

• Multiple wifi clients can use this for network access
• Multiple "WAN" options
• Multiple VPN connections (OpenVPN, Wireguard, IPSEC) e.g.
  • Privacy VPN for general internet traffic
  • Wireguard to connect back to home network
• Ad-blocking via PiHole
• Local file sharing via Samba/SMB
• Locally-hosted web applications with valid hostnames and valid SSL certs (via Let's Encrypt).
  • SearxNG
  • Jellyfin
  • Pairdrop
  • CodeServer
  • Snapcast Server
  • myMPD (MPD web UI)
  • Kiwix (including full Wikipedia dump with images)
  • NodeRED
  • CalibreWeb

Travel Router / Access Point

For internet uplink, there are multiple options depending on need. By default, the internal/bulit-in wi-fi is the internet uplink and the USB wi-fi adapter is the client-facing AP interface. This is how I normally keep it configured in my use-cases.

Alternatively, the built-in wi-fi can be used as the client-facing AP and the uplink to the internet can be provided by a USB-tethered smartphone or a USB ethernet adapter --OR-- the internet uplink can be omitted entirely and either the USB or built-in wifi adapters can serve clients (or both: one in 2.4 GHz mode and the other in 5 GHz mode). Fortunately, the built-in wifi chip in the Banana Pi works well in AP mode but that's not always the case (cough Orange Pi Zero W2 cough).

If a PC is connected to USB0 (the OTG port), the device will act as an ethernet gadget. The travel server will add its end of the usb0 interface into the LAN bridge along with the client-side AP. This means the connected PC will be on the same LAN as the wireless clients.

It's also possible to add a USB ethernet adapter and bridge it into the LAN side as well.

Depending on configuration, a small USB-C hub may be needed. I've got one that includes a USB A port, ethernet port, and additional USB C port.

VPNs can also be configured as needed. I've got a privacy one that can route all traffic as well as a Wireguard one that connects back to my home LAN when I'm using it remotely.

DHCP and DNS are both provided by PiHole

Reverse Proxy

All applications hosted on the travel server are fronted by Nginx and use valid Let's Encrypt certificates. This eliminates the need to install a custom CA cert in end devices or have the clients accept an untrusted self-signed cert.

This also ensures all applications are protected by TLS which is required for full functionality of some applications.

How does that work?

The hostname of the travel server (mobile) is a subdomain of my personal, project domain (mydomain.xyz). All applications are a subdomain of that (e.g. jellyfin.mobile.mydomain.xyz), and I simply request a wildcard cert from Let's Encrypt for *.mobile.mydomain.xyz. Currently, Let's Encrypt requires the use of DNS validation when requesting wildcard certificates.

Movies/TV

Movies and TV shows are provided by Jellyfin and are stored on the 1 TB SD card. I've tested 4 simultaneous streams, and the travel server didn't even break a sweat. Granted, it's not transcoding anything so I believe I'm mostly limited by USB, wifi, and/or SD card bandwidth in that regard.

For reliability, the Jellyfin database is stored on the internal 32 GB eMMC rather than the SD card. This both reduces wear and tear on the card as well as proves to be faster and more reliable.

CPU transoding is a non-starter, and the GPU drivers for these boards isn't exactly well supported. The GPU drivers also rely on V4L which Jellyfin has deprecated for hardware transcoding, so I opted to forego transcoding entirely.

To load movies/TV shows on here, I pre-process them with ffmpeg in the following way:

• Scale to 720p to save space
• Encode to H.264 in an MP4 container (including subtitles as mov_text if available) in yuv420p pixel format to avoid the need for remuxing or transcoding
• Map only the primary English audio and subtitle streams to further save space
• Downmix multi-channel audio to two-channel stereo

Music

Music is provided by a combination of MPD and Snapcast and the library is also stored on the 1TB SD card.

MPD manages the music collection while Snapcast allows synchronized multi-room audio and connecting receivers via wifi.

For local playback, I use myMPD web UI and use its streaming feed or use the MPD and Snapcast clients on the end device. There's also a Snapcast client installed on the travel server itself, so if you add a USB speaker it can playback music directly.

Books

It runs Calibre-Web to manage my book collection which is also stored on the 1 TB SD card. When my phone is connected to its wifi, it can use my FBReader app to connect to the Calibre library over OPDS to download books.

Development

The travel server runs CodeServer which is an un-Microsofted web-based version of VSCode. You can set that up however you want, but I've got it setup for:

• React / NextJS development
• Python development
• ESP8266/ESP32 development with Platform.io

Other services it runs to facilitate development include:

• NodeJS and Bun
• Postgres (via Docker)
• Mosquitto MQTT
• Redis
• CouchDB
• NodeRED

Offline Knowledge

Kiwix is installed with a large selection of ZIMS for offline reference.

• DevDocs for React, Bun, NodeJS, ExpressJS, NextJS, etc. Pretty much every major libarary and framework I work with has offline docs
• Full text Wikipedia dump with images (approx 130GB)

Search

I installed SearxNG so I always have an ad-free, AI-free, no BS search engine available.

File Sharing

The travel server has a few different ways to share files:

• Samba (SMB) shared folder
• PairDrop for quick and easy one-to-one local sharing in the browser or phone app
• SSHFS (alternative method of accessing the SMB shares

Future Plans / Not Yet Implemented

• Add data passthrough to the UPS board so a host PC can charge the UPS/power the travel server while also enumerating it as a USB ethernet device. Currently the UPS board only passes power and plugs into the peripheral USB port.
• Add some kind of tile server and map viewer. Inspired by this project.
• Set up captive portal so Android (and probably Apple, too) devices don't freak out if there's no internet uplink. Currently requires an annoying "Stay connected to this network" and enabling airplane mode so that DNS will work over the wifi connection if there's no internet uplink available.
• Make a web UI to manage services/configs. Currently, config changes require SSH-ing in and modifying the config directly. I do have preset configs for different "modes" but you still have to swap them around by hand.
• Design and 3D print a case that can hold the UPS board and the travel server itself while allowing the travel server to be "ejected" (basically I imagine it slotting into it from the outside and connecting to fixed USB and mini HDMI connectors embedded in the case).

Decades before we had HomeAssistant, you could hook your IBM PC, Commodore 64, TRS-80, and several other vintage home computers into an X-10 interface and control your devices from your PC.

Our 1996 IBM Aptiva came with the IBM Home Director which was based on the same X-10 hardware and had a nice GUI.

The lone exception is Pudding in a Cloud because it's delicious.

DS9 S7E04 - Take Me Out to the Holosuite

Let's hear the runners up in the comments.

Edit: Finally got the reference video clip to upload

Just came across this site collecting the pettiest complaints from around the world and figured it'd be right up Lemmy's alley considering, well, how every 3rd post/comment is complaining about something. So channel your embitteredness and share what petty thing is currently annoying you.

It's got a leaderboard by country, so let's see who the whiniest country is.

Note I'm not affiliated with this site, just saw a few articles about it and had a good laugh after seeing some of the petty complaints.

For starters, yes, we have A/C and it works. I installed the first phase of my PV system last week and have been trying to go solar-only during this heat wave. Unfortunately, I only budgeted for 3 KW of solar in the first phase of this project, and the central A/C is about 3.5 KW. That means I can run the A/C fine during the day - drawing the difference from the batteries and charging them back up when the A/C cycles off - but at night, it's a straight 65 amp draw from the batteries. Due to the current heat wave, its also running more than it normally would, so the PV is struggling to keep the batteries up.

S.O. and I spent yesterday afternoon and evening downstairs in the basement where it was nice and cool and just turned off the A/C. It was about 11 PM when the movie we were watching finished so we decided to call it a night. Came upstairs, and it was 85 degrees. Yikes.

Rather than run the A/C to pump out almost 20 degrees of accumulated heat, we just opened all the windows hoping it would naturally cool down overnight and the A/C could cool it the rest of the way down in the morning.

We've also got a little 5,000 BTU (450 watt) window unit in the bedroom, so we brought the dogs in with us, closed the door, and turned that on. It's pretty easy on the house battery, and we slept comfortably.

When we got up around 6:30 this morning and opened the bedroom door, it was like walking into an oven. Despite the outside temp dropping to 70 degrees overnight, the house only cooled 2 degrees from 85 to 83. S.O immediately caved and turned the A/C on (don't blame him at all) and it's been been running constantly for about 2 hours now pumping out the accumulated heat. House battery is down to about 38% as of this writing, and the sun is just starting to hit the roof panels in useful amounts.

Today's forecast is 99 degrees and afternoon thunderstorms, so I may have to cave and switch back to utility power for the rest of the heat wave (the rest of the weekend is supposed to be cloudy and hot).

Lessons learned:

• Add more PV to the roof ASAP
• Buy S.O. something nice for going along with my solar-only shenanigans this week
• It would have probably saved energy in the long run to have run the A/C the whole time at a higher temp than leaving it off and then pumping out about 14 hours of accumulated heat.
• Updating the house's insulation is probably the next project I need to plan

Despite a painful familiarity with filling out Scantron forms, I've never seen the machine they were fed into. This video shows how they work, how the answers were programmed, and dives into its internals.

If you just want to see the guts of it, skip to about 14:30