Breathe New Life Into Payphones With Asterisk

January 5, 2015 by Rick Osgood 21 Comments

Payphones used to be found on just about every street corner. They were a convenience, now replaced by the ubiquitous mobile phone. These machines were the stomping grounds for many early computer hackers, and as a result hold a place in hacker history. If you’ve ever wanted to re-live the good ol’ days, [hharte’s] project might be for you.

[hharte] has been working to make these old payphones useful again with some custom hardware and software. The project intends to be an interface between a payphone and an Asterisk PBX system. On the hardware side, the controller board is capable of switching various high voltage signals required for coin-line signaling. The controller uses a Teensy microcontroller to detect the hook status as well as to control the relays. The current firmware features are very basic, but functional.

[hharte] also wrote a custom AGI script for Asterisk. This script allows Asterisk to detect the 1700hz and 2200hz tones transmitted when coins are placed into the machine. The script is also in an early stage, but it will prompt for money and then place the call once 25 cents has been deposited. All of the schematics and code can be found on the project’s github page.

[Thanks mies]

Representation of cosmic light hitting a smartphone's screen.

Detect Cosmic Rays With Your Smartphone Using CRAYFIS

October 17, 2014 by Theodora Fabio 6 Comments

[Daniel Whiteson and Michael Mulhearn], researchers at the University of California, have come up with a novel method of detecting ultra-high energy cosmic rays (UHECR) using smartphones. UHECR are defined as having energy greater than 10¹⁸eV. They are rare and very difficult to detect with current arrays. In order to examine enough air showers to detect UHECR, more surface area is needed. Current arrays, like the Pierre Auger Observatory and AGASA, cannot get much larger without dramatically increasing cost. A similar THP Quarterfinalist project is the construction of a low-cost cosmic ray observatory, where it was mentioned that more detection area is needed in order to obtain enough data to be useful.

[Daniel Whiteson and Michael Mulhearn] and colleagues noted that smartphone cameras with CMOS sensors can detect ionizing radiation, which means they also will pick up muons and high-energy photons from cosmic rays. The ubiquitous presence of smartphones makes their collective detection of air showers and UHECR an intriguing possibility. To make all this happen, [Whiteson and Mulhearn] created a smartphone app called CRAYFIS, short for Cosmic RAYs Found In Smartphones. The app turns an idle smartphone into a cosmic ray detector. When the screen goes to sleep and the camera is face-down, CRAYFIS starts taking data from the camera. If a cosmic ray hits the CMOS sensor, the image data is stored on the smartphone along with the arrival time and the phone’s geolocation. This information is uploaded to a central server via the phone’s WiFi. The user does not have to interact with the app beyond installing it. It’s worth noting that CRAYFIS will only capture when the phone is plugged in, so no worries about dead batteries.

The goal of CRAYFIS is to have a minimum of one million smartphones running the app, with a density of 1000 smartphones per square kilometer. As an incentive, anyone whose smartphone data is used in a future scientific paper will be listed as an author. There are CRAYFIS app versions for Android and iOS platforms according to the site. CRAYFIS is still in beta, so the apps aren’t publicly available. Head over to the site to join up!

[via Science]

Hacking A Pogoplug Into A $20 PBX

September 15, 2014 by Eric Evenchick 25 Comments

The Pogoplug Series 4 is a little network attached device that makes your external drives accessible remotely. Under the hood of this device is an ARM processor running at 800 MHz, which is supported by the Linux kernel. If you’re looking to build your own PBX on the cheap, [Ward] runs us through the process. Since the Pogoplug 4 is currently available for about $20, it’s a cheap way to play with telephony.

Step one is to convert the Pogoplug to Debian, which mostly requires following instructions carefully. After the Pogoplug is booting Debian, the Incredible PBX bundle can be installed. We’ve seen this bundle running on a Raspberry Pi in the past. Incredible PBX’s preconfigured setup based on Asterisk and FreePBX gives a ton of functionality out of the box.

With your $20 PBX running, there’s a lot that can be done. Google’s Voice service allows unlimited free calling to the USA and Canada. With Internet connectivity, you get email notifications for voicemails, and can query WolframAlpha by voice.

USB Rotary Phone: A Lync To The Past

July 22, 2014 by Kristina Panos 16 Comments

[Ivan] is fed up with all this rampant virtualization. When his company took away his physical desk phone in favor of using MS Lync, he was driven to build a USB rotary phone. His coworkers loved it and one of them asked [Ivan] to build another. The build log focuses on converting his coworker’s vintage brass and copper number that must weigh a ton.

He had to do a bit more work with this one because it had rusted out inside and a few of the contacts were bent. The good news is that the speaker and microphone were in working order and he was able to use them both. After restoring the stock functionality, he added a USB sound card and created a USB keyboard using a PIC32MX440F256H.

The rotary phone’s dial works using two switches, one that’s open and one that’s closed when no one is dialing. Once dialing is detected, the open switch closes and the closed switch clicks according to the dialed digit (ten clicks for 0). [Ivan] also reads the switch hook state and has added debouncing. This gave him some trouble because of the quick response expected by the PC bus, but he made use of interrupts and was allowed to keep his seat.

Please stay on the line. [Ivan]’s videos will be with you shortly.

Continue reading “USB Rotary Phone: A Lync To The Past” →

Adding A SIM Card To The Photon Q 4G LTE

December 2, 2013 by Mathieu Stephan 6 Comments

[Charles] is a big fan of phones that have physical keyboards. He thinks they are better suited for writing lengthy emails, but unfortunately his HTC Desire Z was getting old so he had to replace it. [Charles] therefore decided to import the Motorola Photon Q from the USA which exposed one major problem. The Verizon phone uses CDMA so there is nowhere to put a GSM SIM. But a bit of hacking allowed him to add a SIM card slot to it. Even though he’s not the one who originally found this hack (XDA thread here), his write-up is definitely an interesting read. To perform this modification, he needed a hot air reflow station, a soldering iron, a Dremel with the appropriate cutting wheel and several SIM card slot assemblies from the Galaxy S3 (as the first ones usually get burned during the disassembly process).

Obviously the first steps involved opening the phone, which may have taken a while. Using hot air, [Charles] removed the EMI shield covering the SIM card IC . He then extracted the latter using the same technique. Finally, he removed another EMI shield covering the contacts to which the SIM card slot should be connected. A few minutes/hours of delicate soldering and case modding later, [Charles] could use his SIM card on his brand new phone.

5 Digit Security Code Activated Relay Using Mostly Discrete Circuitry

October 1, 2013 by Todd Harrison 8 Comments

Let’s rollback the hobby electronics calendar a few decades with [myvideoisonutube’s] alarm activation control circuit using a matrix style phone keypad. The circuit is quite old using CMOS 4081 with 4 ‘AND’ gates to hardwire the access code. [myvideoisonutube] references [Ron’s] “Enhanced 5-Digit Alarm Keypad” schematic for this build changing the recommend keypad with a more common matrix style keypad found in touch pad phones. These types of matrix keypads wouldn’t work outright for the input so he cut some traces and added hookup wires to transform it into a keypad with common terminals and separately connected keys. We love seeing such hacked donor hardware even when it requires extensive modifications. [Ron’s] source circuit included a simple enough to build tactical button keypad if you can’t find a suitable donor phone.

Learning how to use mostly discrete components instead of a microcontroller would be the core objective to build this circuit outside of needing a key-code access point or other secure 12 V relay activated device. Such a device would be quite secure requiring a 4 digit “on” code and 5 digits for “off”. You couldn’t just pull off the keypad and hotwire or short something to gain access either. The 4 digit on “feature” does knock the security down quite a lot. However, all keys not in the access code are connected to the same point so you could increase your security by using a pad with more keys.

On [Ron’s] site you will find a detailed construction guide including top and bottom view for placement of all the components on veroboard. Join us after the break to watch [myvideoisonutube] demo his version.

Continue reading “5 Digit Security Code Activated Relay Using Mostly Discrete Circuitry” →

Adding Wireless Charging To Any Phone

June 19, 2013 by Brian Benchoff 49 Comments

The wireless charging options available on flagship phones is a great feature, but most of us aren’t rocking the latest and greatest cellphone. [Daniel] came up with a great mod that adds wireless charging to just about every cellphone ever, at a very low price and a few bits and bobs ordered off eBay.

[Daniel] used a Palm Touchstone inductive charger – available for a few bucks on eBay – along with an inductive charging circuit from a Palm Pixi. This charging circuit was designed to complement the Touchstone charger, and is simple enough to wire up; all [Dan] needed to do was put the coil and charging circuit near the charge, and it output 5 Volts to charge any phone.

To get the power from the charging circuit into his phone’s battery, [Daniel] simply wired the output of the coil’s circuit to the USB in on the phone. The space inside his S2 was pretty tight but he was able to come up with two ways to install the charging circuit, for use with either the stock back cover or a third-party case.

For anyone with a soldering iron, it’s a quick bit of work to add wireless charging to any phone. We’re loving [Dan]’s solution, as the Palm gear he used is so readily available on eBay and junk drawers the world over.