Mesh Network Telephony Over Bluetooth On Android Phones

Telephony is a bit of a mixed bag. On the one hand, being able to talk to people in far off places is kind of neat, at least in theory. On the other hand, you’re usually reliant on a centralized network, which isn’t ideal to the mindset of most hackers.[Gautam]’s MeshLive project deals with that last one, offering a decentralized mesh network solution based on Bluetooth for Android phones that can handle both voice and video.

Rather than relying on dedicated hardware, this particular mesh piggybacks on your phone, and exists only as an Android application. Calls are end-to-end encrypted for both voice and video — though two-way video calling is still experimental. More testing has gone into video broadcasting, where a stream goes out one-way. The capability is available for voice, as well.

Each user has a unique identifier that can be scanned to create contacts, but it isn’t otherwise clearly identifiable to everybody. You’ll only appear with a random name that changes every 15 minutes to other users in range who aren’t your contacts. Range is of course the Achilles heel of this project, since it’s using the Bluetooth hardware of ordinary smartphones. It’s possible to extend the range of Bluetooth significantly with the right hardware, but we imagine most folks aren’t carrying directional antennas around with them. While every phone does forward the signal to as many others as it can, it can only do so for about 20 meters.

Of course LoRa remains the protocol of choice for mesh networking, though it’s normally used for text messages only. We have seen voice packets over LoRa, but anything LoRa requires dedicated hardware while this only requires an app.

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Meta Portal Given New Life As Extended Display

The Meta Portal and associated devices are effectively defunct, having been abandoned by the company in 2022. If you’ve still got one at home, you might be wondering what to do with it. That’s where Wormhole Display from [pgodlews] comes in handy.

The thing about the Meta Portal, and much of the rest of the related lineup, is that they were effectively just heavily branded Android tablets. The screens and speakers were good, and the basic functionality was all there — albeit locked down somewhat to prevent users from easily repurposing them at will. However, it’s possible to enable Android Debug Bridge (ADB) and turn the device to doing your own bidding.

To that end, [pgodlews] built Wormhole Display as an APK that can be dropped on to the Meta Portal to make it an extendable display for Apple devices. It shows up via AirPlay, letting you use it as a wireless display for your Mac, iPhone, or iPad. You can do screen mirroring or use it as an extended display, as desired, including use of the Portal’s speakers if needed. Under the hood, it’s an Android port of UxPlay, a Unix AirPlay server which uses Android’s MediaCodec and AudioTrack in place of GStreamer to take advantage of the Meta Portal’s onboard H.264 decoder.

Extended displays can be incredibly useful, so if you’ve got an old Meta Portal laying around, consider putting it back to work. We’ve seen it done with e-readers, too. If you’ve got your own hacks to repurpose old, forgotten hardware, don’t hesitate to let us know on the tipsline!

There’s A Whole Computer Inside This Mouse

[Gadget Industry] bills it as “a PC inside a Mouse“, but that depends on your definition of a “PC”. This is a Personal Computer inside a mouse, yes, but there’s nothing IBM-compatible about the tiny ARM board he squeezes inside what’s normally a peripheral — it actually started life as a smartphone, which only takes this build up a notch compared to starting with a single-board computer like a Pi.

Specifically, he starts with a Galaxy S21 5G. Starting with a Samsung means he can leave the stock Android alone and just take advantage of Samsung’s DeX desktop mode, rather than layer a Linux environment on top or replace the operating system entirely with something like Postmarket OS, which are both viable options.

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Quick Share Implemented On A Kindle

Quick Share is a useful tool for flipping files between Android smart phones in a fuss-free wireless manner. [unrealJune] has now implemented the feature on Kindle devices.

You’ll need a jailbroken Kindle to use this, which is running the Kindle Unified Application Launcher and KOReader as well. You’ll also want SSH access, and a machine that has Go and Docker for you to build the project. [unrealJune] steps through the steps to compile and install the Quick Share plugin to KOReader, as well as explaining how it works. Notably, it’s receive only—so you can spit files onto the Kindle, but you can’t send them from the Kindle to other devices. The Kindle will also automatically accept files, which is worth noting if you’re security conscious. If there’s no network, the Kindle is also able to appear as its own AP if needed.

Think of this as a nifty convenience if you find yourself regularly trying to truck files on to your jailbroken Kindle. It’s also a neat to see a Quick Share implementation from the open source world. Between-device sharing still sucks, as we’ve discussed before, but there are at least attempts being made to make it better. That’s something!

Hacking Amazon Echo Show 8 3rd Gen Via UART And EMMC

Even with Amazon’s Echo Show devices running Linux in the form of the Android-derived FireOS, using them for non-Amazon approved purposes can be a chore at best. In the case of the Echo Show 8 even simple workarounds using ADB and the bootloader have been locked-down, requiring more drastic measures. Here [Vowed] over at the XDA forums shows off one such hack, involving directly tapping into the device’s eMMC.

Suffice it to say that this is not a hack for the faint of heart, with even the iFixit teardown guide for this device being rather daunting. Even after you get access to the mainboard, you still have to remove or cut open the metal can that covers the eMMC, so that you can unleash an eMMC programmer on it. It’s best to make sure to make a backup image of the original contents too, just in case you have to restore things.

With the shield out of the way you can solder fine wires to pads that connect to the eMMC to program it. You also have to solder wires to pads for the UART, though if you’re fancy you can also create a custom pogo pin adapter. With a serial connection established to the original firmware you can then enable features like ADB, and courtesy of the connected eMMC adapter it’s possible to directly alter system files to make rooting as easy as possible.

In addition to rooting the system you can also do a straight replacement of the eMMC contents, such as the demonstrated Debian installation. Even if not the most easy of mods, it’s good to see that it’s possible to repurpose these devices.

(Top image: Amazon Echo Show 8 3rd generation mainboard. Credit: iFixit, CC BY-NC-SA 3.0.)

A phone running the XFCE desktop environment is placed on a desk, with a wireless keyboard in front of it.

Linux On Android Provides Inexpensive, Powerful Computing

In some parts of the world it’s common for cell service providers to sell new phones at a price significantly below market value, with the caveat that these phones are locked to that service provider alone. It’s questionable whether this practice is good for consumers, but as [Gabriel Broussard Korr] notes, it’s an opportunity for hackers: since it’s possible to run a Linux environment on these phones, they make an inexpensive source of quite powerful computing hardware.

In this case, [Gabriel] was using the Moto G Power 2024, which has 128 GB of storage, 12 GB of RAM, and costs less than $50 when carrier-locked. Rather than trying to install a mobile-oriented Linux distribution (such as postmarketOS), [Gabriel] installed Termux, a terminal emulator which provides a Linux environment within Android. Before doing this, he set up the phone and configured a number of settings for a better Linux experience. Since automatic updates can interfere with these settings, and since none of the provided settings effectively disable these, he used NetGuard to block Internet access from the updater app and from Google Play services.

The next step was to actually install Termux, as well as an X11 extension and an app which exposes an API for Termux. The desktop environment (XFCE in this case) was installed through Termux, and [Gabriel] wrote a shell script to go through the steps of starting it. XFCE worked well on mobile devices because of its full-desktop zoom capability. Even running Linux indirectly, the experience was smooth; [Gabriel] found that GIMP, Shotcut, and VS Code all performed well.

It’s not quite the same set of software, but we’ve previously featured a guide to setting up a similar Linux environment using Termux and AnLinux. Lindroid provides a similar containerized Linux environment; on the other hand, you can also use postmarketOS to make a server from an old phone.

Ask Hackaday: Do You Need A Tablet?

There’s an old saying that the happiest days of a boat owner’s life are the day they buy the boat, and the day they sell it. For me, the happiest days of an Android tablet owner’s life are the day they buy a new one, and the day they buy a newer one. For some reason, I always buy tablets with great expectations, get them set up, and then promptly lose them in a pile on my desk, not to be seen again. Then a shiny new tablet gets my attention in a year or so, and the cycle repeats.

You might be thinking that I just buy cheap junk tablets. It is true that I have. But I have also bought new Galaxy and Asus tablets with the same result. Admittedly, I have owned several Surface Laptops and Pros, and I do use them. But I can’t remember the last time I have used one without the keyboard. They aren’t really tablets — they are just laptops that can also be heavy, awkward tablets.

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