Send Old-Fashioned Pager Messages With New-Fashioned Hardware

In a world of always-connected devices and 24/7 access to email and various social media and messaging platforms, it’s sometimes a good idea to take a step away from the hustle and bustle for peace of mind. But not too big of a step. After all, we sometimes need some limited contact with other humans, so that’s what [EverestX] set out to do with his modern, pocket-sized communication device based on pager technology from days of yore.

The device uses the POCSAG communications protocol, a current standard for pager communications that allows for an SMS-like experience for those still who still need (or want) to use pagers. [EverestX] was able to adapt some preexisting code and port it to an Atmel 32u4 microcontroller. With a custom PCB, small battery, an antenna, and some incredibly refined soldering skills, he was able to put together this build with an incredibly small footprint, slightly larger than a bottle cap.

Once added to a custom case, [EverestX] has an excellent platform for sending pager messages to all of his friends and can avoid any dreaded voice conversations. Pager hacks have been a favorite around these parts for years, and are still a viable option for modern communications needs despite also being a nostalgic relic of decades past. As an added bonus, the 32u4 microcontroller has some interesting non-pager features that you might want to check out as well.

Thanks to [ch0l0man] for the tip!

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Hackaday Links: July 26, 2020

An Australian teen is in hot water after he allegedly exposed sensitive medical information concerning COVID-19 patients being treated in a local hospital. While the authorities in Western Australia were quick to paint the unidentified teen as a malicious, balaclava-wearing hacker spending his idle days cracking into secure systems, a narrative local media were all too willing to parrot, reading down past the breathless headlines reveals the truth: the teen set up an SDR to receive unencrypted POCSAG pager data from a hospital, and built a web page to display it all in real-time. We’ve covered the use of unsecured pager networks in the medical profession before; this is a well-known problem that should not exactly take any infosec pros by surprise. Apparently authorities just hoped that nobody would spend $20 on an SDR and an afternoon putting it all together rather than address the real problem, and when found out they shifted the blame onto the kid.

Speaking of RF hacking, even though the 2020 HOPE Conference is going virtual, they’ll still be holding the RF Hacking Village. It’s not clear from the schedule how exactly that will happen; perhaps like this year’s GNU Radio Conference CTF Challenge, they’ll be distributing audio files for participants to decode. If someone attends HOPE, which starts this weekend, we’d love to hear a report on how the RF Village — and the Lockpicking Village and all the other attractions — are organized. Here’s hoping it’s as cool as DEFCON Safe Mode’s cassette tape mystery.

It looks like the Raspberry Pi family is about to get a big performance boost, with Eben Upton’s announcement that the upcoming Pi Compute Module 4 will hopefully support NVMe storage. The non-volatile memory express spec will allow speedy access to storage and make the many hacks Pi users use to increase access speed unnecessary. While the Compute Modules are targeted at embedded system designers, Upton also hinted that NVMe support might make it into the mainstream Pi line with a future Pi 4A.

Campfires on the sun? It sounds strange, but that’s what solar scientists are calling the bright spots revealed on our star’s surface by the newly commissioned ESA/NASA Solar Orbiter satellite. The orbiter recently returned its first images of the sun, which are extreme closeups of the roiling surface. They didn’t expect the first images, which are normally used to calibrate instruments and make sure everything is working, to reveal something new, but the (relatively) tiny bright spots are thought to be smaller versions of the larger solar flares we observe from Earth. There are some fascinating images coming back from the orbiter, and they’re well worth checking out.

And finally, although it’s an old article and has nothing to do with hacking, we stumbled upon Tim Urban’s look at the mathematics of human relations and found it fascinating enough to share. The gist is that everyone on the planet is related, and most of us are a lot more inbred than we would like to think, thanks to the exponential growth of everyone’s tree of ancestors. For example, you have 128 great-great-great-great-great-grandparents, who were probably alive in the early 1800s. That pool doubles in size with every generation you go back, until we eventually — sometime in the 1600s — have a pool of ancestors that exceeds the population of the planet at the time. This means that somewhere along the way, someone in your family tree was hanging out with someone else from a very nearby branch of the same tree. That union, likely between first or second cousins, produced the line that led to you. This is called pedigree collapse and it results in the pool of ancestors being greatly trimmed thanks to sharing grandparents. So the next time someone tells you they’re descended from 16th-century royalty, you can just tell them, “Oh yeah? Me too!” Probably.

A Spectrum Analyzer For The Smart Response XE

Remember the Girl Tech IM-me? It was a hot-pink clearance rack toy that suddenly became one of the hottest commodities in the hacking world when it was discovered they could be used for all sorts of radio frequency shenanigans. Now they go for triple digits on eBay, if you can even find one. Well, we’re probably about to see the same thing happen to the Smart Response XE.

Thanks to the work of a hacker named [ea], this cheap educational gadget is finally starting to live up to the potential we saw in it back when a teardown revealed it was powered by an Arduino-compatible ATmega128RF chip. With a big screen, a decent QWERTY keyboard, and integrated wireless hardware, it seemed obvious that the Smart Response XE was poised to be the next must-have repurposed piece of kit.

Though as it turns out, [ea] isn’t using the device’s built-in wireless hardware. Step one in this exceptionally well documented and photographed project is to tack a CC1101 transceiver module to the SPI pins on the ATmega128RF. Then with the appropriate firmware loaded up, that nice big screen will show you what’s happening on the 300 MHz, 400 Mhz and 900 MHz bands.

But the fun doesn’t stop there. With the CC1101-modified Smart Response XE, there’s a whole new world of radio hacks you can pull off. As a proof of concept, [ea] has also included a POCSAG pager decoder. Granted the RTL-SDR has already made pulling pager messages out of the air pretty easy, but there’s something to be said for being able to do it on something so small and unassuming.

If you can’t tell, we’re exceptionally interested in seeing what the community can do with the Smart Response XE. At the time of this writing, the going rate on eBay for a good condition unit looks to be about $10 USD, plus the $3 or so for the CC1101 module. But the prices went through the roof when we first posted about it, so get them cheap while you still can.

[Thanks to bburky for the tip.]

FLEX Pager Protocol In Depth

We love pager hacks. One of our earliest head-slappers was completely reverse-engineering a restaurant pager’s protocol, only to find out that it was industry-standard POCSAG. Doh!

[Corn] apparently scratches the same itch, but in the Netherlands where the FLEX protocol is more common. In addition to walking us through all of the details of the FLEX system, he bought a FLEX pager, gutted it, and soldered on an ATMega328 board and an ESP8266. The former does the FLEX decoding, and the latter posts whatever it hears on his local network.

These days, we’re sure that you could do the same thing with a Raspberry Pi and SDR, but we love the old-school approach of buying a pager and tapping into its signals. And it makes a better stand-alone device with a lot lower power budget. If you find yourself in possession of some old POCSAG pagers, you should check out [Corn]’s previous work: an OpenWRT router that sends pages.

Bringing A Legacy Pager Network Back To Life

[Jelmer] recently found his old pager in the middle of a move, and decided to fire it up to relive his fond memories of receiving a page. He soon discovered that the pager’s number was no longer active and the pager’s network was completely shut down. To bring his pager back to life, [Jelmer] built his own OpenWRT-based pager base station that emulates the POCSAG RF pager protocol.

[Jelmer] opened up his pager and started probing signals to determine what protocol the pager used. Soon he found the RF receiver and decoder IC which implements the POCSAG pager protocol. [Jelmer] began going through the sparse POCSAG documentation and assembled enough information to implement the protocol himself.

[Jelmer] used a HLK-RM04 WiFi router module for the brains of his build, which talks to an ATMega that controls a SI4432 RF transceiver. The router runs OpenWRT and generates POCSAG control signals that are transmitted by the SI4432 IC. [Jelmer] successfully used this setup to send control signals to several pagers he had on hand, and plans on using the setup to send customizable alerts in the future. [Jelmer] does note that operating this device may be illegal in many countries, so as always, check local frequency allocations and laws before tackling this project. Check out the video after the break where a pager is initialized by [Jelmer]’s transmitter.

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