Getting Root On Cheap WiFi Repeaters, The Long Way Around

What can you do with a cheap Linux machine with limited flash and only a single free GPIO line? Probably not much, but sometimes, just getting root to prove you can is the main goal of a project. If that happens to lead somewhere useful, well, that’s just icing on the cake.

Like many interesting stories, this one starts on AliExpress, where [Easton] spied some low-cost WiFi repeaters, the ones that plug directly into the wall and extend your wireless network another few meters or so. Unable to resist the siren song, a few of these dongles showed up in the mailbox, ripe for the hacking. Spoiler alert: although the attempt on the first device had some success by getting a console session through the UART port and resetting the root password, [Easton] ended up bricking the repeater while trying to install an OpenWRT image.

The second attempt, this time on a different but similar device, proved more fruitful. The rudimentary web UI provided no easy path in, although it did a pretty good job enumerating the hardware [Easton] was working with. With the UART route only likely to provide temptation to brick this one too, [Easton] turned to a security advisory about a vulnerability that allows remote code execution through a specially crafted SSID. That means getting root on these dongles is as simple as a curl command — no hardware hacks needed!

As for what to do with a bunch of little plug-in Linux boxes with WiFi, we’ll leave that up to your imagination. We like [Easton]’s idea of running something like Pi-Hole on them; maybe Home Assistant would be possible, but these are pretty resource-constrained machines. Still, the lessons learned here are valuable, and at this price point, let the games begin.

18650 Brings ESP8266 WiFi Repeater Along For The Ride

We’re truly fortunate to have so many incredible open source projects floating around on the Internet, since there’s almost always some prior art you can lean on. By combining bits and pieces from different projects, you can often save yourself a huge amount of time and effort. It’s just a matter of figuring out how all the pieces fit together, like in this clever mash-up by [bethiboothi] that takes advantage of the fact that the popular TP4056 lithium-ion battery charger module happens to be almost the exact same size of the ESP-01.

By taking a 3D printed design intended to attach a TP4056 module to the end of an 18650 cell and combining it with an ESP8266 firmware that turns the powerful microcontroller into a WiFi repeater, [bethiboothi] ended up with a portable network node that reportedly lasts up to three days on a charge. The observed range was good even with the built-in PCB antenna, but hacking on an external can get you out a little farther if you need it.

While it doesn’t appear that [bethiboothi] is using it currently, the esp_wifi_repeater firmware does have an automatic mesh mode which seems like it would be a fantastic fit for this design. Putting together an impromptu mesh WiFi network with a bunch of cheap battery powered nodes would be an excellent way to get network connectivity at an outdoor hacker camp, assuming the ESP’s CPU can keep up with the demand.

Hackaday Links: November 22, 2015

There’s a new documentary series on Al Jazeera called Rebel Geeks that looks at the people who make the stuff everyone uses. The latest 25-minute part of the series is with [Massimo], chief of the arduino.cc camp. Upcoming episodes include Twitter co-creator [Evan Henshaw-Plath] and people in the Madrid government who are trying to build a direct democracy for the city on the Internet.

Despite being a WiFi device, the ESP8266 is surprisingly great at being an Internet of Thing. The only problem is the range. No worries; you can use the ESP as a WiFi repeater that will get you about 0.5km further for each additional repeater node. Power is of course required, but you can stuff everything inside a cell phone charger.

I’ve said it before and I’ll say it again: the most common use for the Raspberry Pi is a vintage console emulator. Now there’s a Kickstarter for a dedicated tabletop Raspi emulation case that actually looks good.

Pogo pins are the go-to solution for putting firmware on hundreds of boards. These tiny spring-loaded pins give you a programming rig that’s easy to attach and detach without any soldering whatsoever. [Tom] needed to program a few dozen boards in a short amount of time, didn’t have any pogo pins, and didn’t want to solder a header to each board. The solution? Pull the pins out of a female header. It works in a pinch, but you probably want a better solution for a more permanent setup.

Half of building a PCB is getting parts and pinouts right. [Josef] is working on a tool to at least semi-automate the importing of pinout tables from datasheets into KiCad. This is a very, very hard problem, and if it’s half right half the time, that’s a tremendous accomplishment.

Last summer, [Voja] wrote something for the blog on building enclosures from FR4. Over on Hackaday.io he’s working on a project, and it’s time for that project to get an enclosure. The results are amazing and leave us wondering why we don’t see this technique more often.

Bringing WiFi Into A Mobile Hackerspace

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[Philipp Protschka] has a pretty awesome mobile hackerspace (MHS) trailer. The only problem? How do you get WiFi when you’re inside what is basically a Faraday’s cage?

He didn’t think he’d have a problem, since he has a fairly powerful router (Netgear R7000 Nighthawk), not more than 20m from the trailer. But as soon as he shuts the door, he loses all connectivity — he can’t even see his SSID. Leaving the door open a crack results in a signal with a speed of about 54Mbits — not bad, but when it’s cold outside this really isn’t an option.

The solution? Install a WiFi repeater with an external antenna. He’s using a TP link station with two antennas — he’s removed one and hooked it up to a rugged outdoor antenna that gives the MHS a bit of an FBI van look — awesome. With the repeater in place he’s suddenly got access to over 24 SSID’s in the neighborhood from inside! It’ll also be extra handy when travelling because with the extra range it means he’ll be able to hook into local WiFi networks with ease.

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200 Pound, WiFi Deploying Robot Ran Over My Foot

[Adam Bercu] and [Dan Landers] from Artisan’s Asylum in Somerville, MA brought a very, very cool toy to Maker Faire this year. It’s a two hundred pound WiFi repeater deploying robot able to amble across unforgiving terrain and my foot.

The robot is controlled through a web interface with the help of a front-mounted web cam with pan and tilt controls. All the signals are sent through a WiFi connection to a node.js web server; not the best way to communicate with a robot over long distances, but [Adam] and [Dan] have a few tricks up their sleeve.

On the back of the robot are two Pelican cases loaded up with a battery and a Linksys WRT54G wireless router. When the robot reaches the limits of its range, it activates a solenoid, dropping a WiFi repeater. This repeater has enough battery juice to stay powered for about a day and a half, meaning the robot can make multiple trips to deploy a wireless network through some very hostile terrain. Perfect for disaster and search and rescue operations.

There are two videos after the break: the first is [Dan] going over the capabilities of his tank bot and the second is a short demo of the bot tearing up the grass at Maker Faire.

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