AN EIGHT YEAR OLD PHONE BOUGHT BROKEN FOR THIRTY DOLLARS NOW RUNS A HOME SERVER ON NINE KILOWATT HOURS A YEAR
An eight year old Xiaomi bought broken for thirty dollars now runs a home server on nine kilowatt hours a year.
by postmarketOS community
HomeAutomation
- difficulty
- ●●●●○
- time
- a weekend-plus
- license
- GPL-3.0
- repo
- repo ACTIVE276 stars
●●●●○ · a weekend-plus · GPL-3.0 · 276 stars · repo ACTIVE
WHAT YOU’LL NEED
- Dev board / microcontroller — runs the project firmware
Partner
COMPAREE VERDICT
postmarketOS is a free and open source Linux distribution that extends the useful life of phones and tablets by replacing the closed software that usually kills them. Hardware Haven tested this with an eight year old Xiaomi Mi A1 bought beaten up for thirty dollars, chosen specifically because it has community-level support. The catch is device support: only a handful of phones run this properly, so check the list before you start. Installation went through fastboot and pmbootstrap to build a minimal image because Plasma Mobile was clunky on this hardware. USB networking let him SSH in and set up WiFi without touching the screen, and Docker needed firewall rules adding before container networking behaved. What runs on it now is Home Assistant in a container, and the numbers are the interesting part: about 0.024 kilowatt hours a day, roughly nine across a year, which came to about four dollars thirty eight in electricity. The phone battery stays in the loop and still reports 99 percent capacity at 4.28 volts, which makes it a server with a built in uninterruptible supply. His verdict on the software was not a sales pitch: clunky, with real issues, and genuinely impressive for what it is. The thing most likely to go wrong is buying a phone that does not have community support and discovering pmbootstrap will not build you a working image.
IN THE REPO
NOT IN THE REPO
- —postmarketOS is GPL-3.0, free and open source with no commercial restrictions.
- —Installation requires fastboot from Android SDK platform tools and pmbootstrap to build a custom image.
- —Only a handful of devices have community-level support — the Xiaomi Mi A1 is one, but the phone in your drawer may not be on the list.
- —Documentation exists but the builder says the process is clunky, with real issues, and requires SSH over USB networking to configure WiFi.
- —Docker container networking required firewall rules before it behaved; this is documented in the community but not always obvious.
- —No BOM or parts list — this is a software project repurposing an old phone, not a hardware build.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
Partner · KickstarterBluHub reads and burns Blu-ray/DVD/CD, adds USB-C, USB-A, SD/TF and 10 Gbps data — plug and play, grand-piano finish.
Videos
Broken phone as a home server (build by Hardware Haven)
No official tutorial or video linked in the payload; community walkthroughs exist but are not provided here.
Gallery
Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Check the postmarketOS device support list for your phone (Only devices with community-level support will work properly. If your phone is not on the list, this project will not work.)
- 2.Install Android SDK platform tools for fastboot(You will need fastboot to flash the phone.)
- 3.Install pmbootstrap and build a minimal image(Plasma Mobile was clunky on the Mi A1; a minimal image is the better answer.)
- 4.Use USB networking to SSH into the phone and configure WiFi(You can set up WiFi without touching the screen.)
- 5.Add firewall rules for Docker container networking(Docker will not behave until you do this; the builder documents it rather than glossing over it.)
Resources
Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.
KNOWN ISSUES
- Buying a phone that does not have community-level support in postmarketOS and discovering pmbootstrap will not build you a working image.
- Assuming Plasma Mobile will run well on old hardware — it is clunky, and a minimal image is the better answer.
- Forgetting to add firewall rules for Docker container networking, which will break before you realise what is wrong.
- Expecting this to be a beginner project — it requires command line Linux, fastboot, SSH, and the patience to debug when things do not work first time.
- Treating the power and cost figures as universal — they are the builder's own measurements on one device, and your mileage will vary.
Will this work on the phone in my drawer?
Only if it has community-level support in postmarketOS. Check the device list first — only a handful of phones are supported properly.
How much does it cost to run?
About 0.024 kilowatt hours a day, roughly nine across a year, which came to about four dollars thirty eight in electricity in the example. Your cost will depend on your local electricity rate.
Do I need to remove the battery?
No — the battery stays in and acts as a built-in uninterruptible supply. The builder's phone still reports 99 percent capacity at 4.28 volts.
Is this easier than a Raspberry Pi?
No. This is harder, clunky, and requires more debugging. The builder says so plainly. The advantage is the built-in UPS, low power draw, and reusing a device you already own.
Community builds
No community builds yet — be the first, we feature the best ones.
Discussion1
FROM THE COMPAREE TEAM
Nine kilowatt hours a year for a home server with built-in backup power — but only if your phone is on the support list. What would you run on yours?
postmarketOS community
postmarketOS is a free and open source Linux distribution for phones and tablets, maintained by a community of developers whose stated mission is to extend the useful life of consumer electronics and give people full control over their own devices. The project exists because what kills a phone is usually closed software, not worn out hardware.
Keep building — related projects
Same category, picked by how close they are to this build.
NO CAD FILESCasaOS: turn a retired office laptop into a private home server that replaces cloud storage
HomeAutomation●●○○○starter
NO CAD FILESTake your router back from its maker in ninety seconds
HomeAutomation●●○○○starter
Partner · KickstarterCodeeBot: build the robot from Lego-compatible bricks and program it by hand; a GPT tutor explains each step.
NO CAD FILESFree your smart plug before they switch the cloud off
HomeAutomation●●●○○moderate
NO CAD FILESTasmota: replace the cloud firmware in a smart plug so it runs entirely on your own network
HomeAutomation●●●●○advanced
DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM17d agoedited
Practical notes from our verification: the payload did not include a repository URL, device support list, or tutorial links, so those fields are left empty rather than fabricated. The builder's power and cost figures are his own measurements on a Xiaomi Mi A1, and he says plainly the software is clunky with real issues — this is not a polished experience, it is a proof that old phones can do more than sit in a drawer. The biggest trap is device support: only a handful of phones have community-level support in postmarketOS, and the builder chose the Mi A1 specifically because it is on that list. Check yours first.