JanOS: Turn your phone into an IoT board (2015) | Hacker News Reader

JanOS: Turn your phone into an IoT board (2015)

janos.io

164 pointsdanboarder30 comments

This appears to be based on Firefox OS (aka "Boot to Gecko" B2G). Unfortunately, that was terminated Sept. 2016 [1]. The links to FOS on the JanOS site (such as "View porting instructions" on the Device List page) no longer work, though there is still a home page on Mozilla [2].

Edit: JanOS project looks to be zombied. The "Read more on our blog" link on the front page returns "Server Not Found".

[1] https://groups.google.com/g/mozilla.dev.fxos/c/FoAwifahNPY/m...

[2] https://support.mozilla.org/en-US/products/firefox-os

I wonder whether all of the FirefoxOS build dependencies for all those devices have been preserved.

(When I built it for a few of those devices, it was layered atop Android, and IIRC the process involved fetching components from various places.)

Unfortunately not. For instance, some devices used repositories that got shut down recently (https://bye.codeaurora.org/).

https://capyloon.org/ is a living fork of Firefox OS

FirefoxOS still lives on as KaiOS for cheap feature phones. So in a way it's still around, just not very relevant for this purpose.

It should be required for vendors to unlock the bootloader on hardware devices that have reached EOL. Think of how much e-waste we could reduce if we were able to repurpose hardware we already own instead of it just going into a landfill or worse incinerated which is often the case with e-waste shipped overseas to low income areas for disposal.

When Galaxy Upcycling was first announced, it was extremely ambitious. However, the final product was cut down by a lot to make room for the economics.

https://www.ifixit.com/News/50450/samsung-galaxy-upcycling-u...

To be honest, it sort of makes sense, why would they want to open themselves upto unlimited brand damage liability from battery fires, while spending untold amount of man hours porting mainline linux onto obsolete platforms they'll never see a cent from anymore - whether it be in other products or through services revenue.

They should just provide drivers for something like Debian. From there on, people could run web servers, Docker, source control servers, NAS stuff, and so on.

Most of the time, Android vendors do provide the drivers (yay GPL), but they're so specific to Android or so poor quality that you'd better think twice about using them anywhere else. They're also out of tree patches, so porting them to a newer kernel is a job unto itself

Debian mostly only distributes mainline Linux kernels, so they should instead contribute to the upstream Linux kernel community.

Maybe it's different in the US, but in Europe, all Samsung phones can have their bootloader unlocked via a simple two-step procedure, so end users can flash whatever they like as the OS. They also have all their Linux kernel source code, along with any changes they've made to other open source components, available at https://opensource.samsung.com, so you can build custom kernels if needed, or port drivers to a mainline branch.

I've repurposed an old Galaxy S7 to run as a remote development server, via this method. I have it set up so it's just like logging into any other Linux box.

It's very different in the US. It's impossible to unlock the bootloaders, get root, etc. Occasionally someone finds a vuln, but as a general rule, no rooting etc samsung phones in the US :/

it's trivial. use this tool:

https://forum.xda-developers.com/t/patched-odin-3-13-1.37625...

do note, the patched out safety checks will definitely allow you to shoot yourself in the foot if you flash the wrong images

>It's very different in the US. It's impossible to unlock the bootloaders, get root, etc.

Sounds like the US would benefit from some EU style legislation.

I don't think it's legislation that causes this. Huawei sold un-unlockable phones in the EU while they were still around.

Folks who do this: how do you keep the battery from bulging and being a fire hazard after a year being constantly connected to a power outlet?

I wanted to do this with an older phone that just two wires going to its battery, so I thought I'd measure the voltage and then just use a step-down converter to supply that same voltage to those two pins. Unfortunately no dice, device can't be fooled to think this is a battery and doesn't even turn on.

I also tried just connecting a huge cap instead of a battery, but realized that if it runs empty the board night just assume the battery discharged too much and will refuse charging it. Also it still didn't work when I tried.

>device can't be fooled to think this is a battery and doesn't even turn on.

Depend on the phone, what battery charging and monitoring IC it uses, but the older ones from the Samsung S2 generation, the ones that still had removable battery, could easily be fooled by adding a resistor to the third BSI/BTEMP terminal (the one in the middle).

I feared that there was a sweet spot for this in the past. The few modern ones where you can still get to the battery have some proprietary connector with a dozen pins where I wouldn't even know where to start.

The one I had was some Noname device from China that really only had two wires going to the battery pack, which I've never seen on any other Android device yet, so I was quite positive given the cheapness that my simple trick would work, but alas.

Funny this project should turn up now. This project started with a container full of phones our company couldn't get rid of and the question "could we do something useful with them". The short version: not really. Phones consume huge amounts of energy and have tiny batteries relative to their power usage. If you want to repurpose them this isn't the way to do it.

Jan, who so modestly (ahem) named this bonsai'd Firefox OS after himself, has since done a lot of interesting things with LoRa and now machine learning. You can find him at http://janjongboom.com/.

If only I can actually run full Linux on the multitude of old phones I have. Its a very affordable k8s cluster!

Have you tried PostmarketOS? If your old phones are on this list[1], you absolutely can turn them into a very affordable k8s cluster!

[1] https://wiki.postmarketos.org/wiki/All_devices

Looks promising! However running a phone 24/7 on the charger is going to make that battery swell pretty fast.

Also can I use Ethernet with an external usb-c adapter?

Yes you can. You can even connect a usb hub and plug Ethernet there along with other needs like storage.

I always wanted to do this for a security camera it seems like all the hardware is there plus a rechargeable battery.

I really wanted to repurpose my old phone as a security camera , but android power management and lack of sensible way to automatically restart the app for an IP camera made it not very practical.

this could be a promising project but device support looks very lacking at this moment.

I also considered postmarketos but AFAIR for my particular phone it didn't support the camera, so I stuck with rooted android with some hacks to slow/pause battery charging (it is holding about 5min anyways)

Ok this is exactly the type of thing I was looking for. Is there work being done to open up the pool of possible hardware even further?

This does look pretty cool; but this could be revolutionary if the hardware support were to significantly widen.

Suggest appending (2015) to the title unless there’s evidence this is still active?

I added that, thanks. Are there any newer approaches to using a spare Android phone as an IoT board, as an alternative to finding a Rasberry Pi that is often out of stock?

Also I'm looking for breakout boards that make it easy to interface with GPIO pins, I've found a few that can do USB to GPIO on sites like Adafruit, but few review of what is available currently and if it works with recent versions of Android, etc.

These line up somewhat, I think:

https://phonk.app/

https://1-10.github.io/zigsim/getting-started.html#install

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