Rotary And Cordless Phones Mashup

This pile of hardware marries telecommunications hardware from distinctly different generations. [Andrew D. Farquharson] wanted the retro look and operation of a rotary phone, with the convenience of a modern cordless. He combined the two technologies to achieve his goal.

The first problem was to find a way to translate the rotary inputs to something he could use. There are already a bunch of projects that use rotary hardware so he didn’t have to reinvent the wheel. He followed this guide to connecting Arduino to a rotary phone.

The next step was to interface with his cordless phone. He ditched the case and soldered rainbow ribbon cable to the entire button matrix. An opto-isolator is used to protect the Arduino while making each connection. Finally, he patched into the mechanism which monitors the cradle to see if the handset has been picked up. It sounds like his code lets you enter the number on the dial, then pick up the handset to actual transmit it through the cordless phone.

Alarm System Makes Sure Your Moving Truck Doesn’t Get Raided

When you move you generally load up everything you own into one truck. If your entire life is ever going to get ripped off, this is probably when it’s going to happen. To guard against the threat [Tim Flint] built his own alarm for a moving truck. If someone opens the door on the truck it’ll alert him via text message. Hopefully he’s got an annoying notification sound that will wake him up in time to catch them red-handed.

The setup is simple and shouldn’t distract you too much from your packing and loading. [Tim] connected a proximity sensor to an Arduino board which has its own WiFi module. The entire thing is housed in the black project box seen above and the proximity sensor is pointed at the moving truck door. When the door is opened the Arduino pushes an alert to Twilio which is configured to send him text messages.

The alarm system doesn’t protect from someone stealing the entire truck… that kind of system is an entirely different project.

Make Cell Phone Calls With Your Arduino

Cellular shields for the Arduino have been around for ages, but this is the first one we’ve seen that turns your Arduino into a proper cell phone.

The shield is based around the SIM900 GSM/GPRS radio module, and is compatible with the SIM908 GSM/GPRS module that adds a GPS receiver. Also on board this shield are a pair of 1/8″ audio jacks, perfect for connecting a microphone and headphones. Yes, you can actually make cell phone calls with your Arduino now.

The real star of this build is the new GSM Shield library. This library of code includes the methods necessary for an Arduino to function as a cell phone (answer, hang up, dial a number), but also includes a lot of improvements for TCP/IP communication.

Even though the cost of getting an Arduino communicating through a GSM or GPRS network is fairly high, we’re thinking this would be the perfect starting point for a completely open source, open hardware cell phone. A phone with the same functionality as an old Nokia brick that is also a MiFy would be an amazing piece of hardware, and would surely make for a profitable Kickstarter.

Turning A MIDI Sequencer Display Into A Tetris Clone

led-midi-display-tetris

Tetris is unquestionably a game for the ages. Despite its simplicity, someone, somewhere will always find a way to port the game (Translation) to just about any electronic device that can handle it.

Earlier this year we showed you a slick MIDI sequencer project that was constructed using an Arduino Mega, which also happened to drive an incredibly detailed touch screen display. [Christian] must have gotten bored with his awesome creation one day, because he pulled the drum level display out of his Arduino Sequencer 808, and turned the LED array into a mini Tetris game.

As you can see in the video below, the game runs pretty well, though from what we can see it lacks any sort of score keeping. We dig it because we never really tire of Tetris clones, and we think it’s great that he kept his 808 sequencer design modular enough that he can pluck different components out for reuse in other projects.

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What You Can Do When A Raspberry Pi Teams Up With An Arduino

We thought that connecting an Arduino to a Raspberry Pi was overkill, but one thing caught our attention. [Jan Stevens] mentions that the RPi is less expensive than the Ethernet Shield. Interesting. As we looked into his writeup a bit more we began to think he’s onto something. [Jan] uses the PHP serial class to communicate between the RPi and Arduino (dead link; Internet Archive). This ends up being a very inexpensive way to bring some of the more powerful web programming options to your hardware devices.

Sure, he’s just driving three RGB LEDs. But the demo video after the break gives us a glimpse as some of the interface options that become available when an embedded Linux machine is in play. He’s using jQuery, AJAX, PHP, and JSON to name a few. If you want to give this a try yourself you can grab the code from his Github repo. Of course we’re going to want to hear about any projects you develop from this starting point!

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Dual Core Arduino For More Pins

There are easy ways of getting more I/O pins for any project; shift registers, I2C expanders, or ADCs will give you plenty of pins for whatever project you have in mind. All these require extra components, though. Enter the ExtraCore library for Arduino, a software library that turns two or more Arduinos into a multi-core microcontroller with more pins than you’ll ever need.

The ExtraCore library comes from [Dustin Andrews], and allows anyone to control the input and output pins of two Arduinos with the same ease as a single Arduino.

The hardware setup is fairly simple – just connect A4, A5, power, and ground on both Arduinos together. After installing the ‘client’ sketch on the second Arduino, you can modify the ‘manager’ sketch to suit whatever project you’re building. From there you’ve nearly doubled the number of Arduino pins your project can control.

It may not be the most practical use of two Arduinos, but it’s certainly impressive. You can pick up [Dustin]’s code over on GitHub.

Arduino Tachometer Tutorial

This tutorial will guide you through the process of building a tachometer around an Arduino. Tachometers are used to measure rotation rate in Revolutions Per Minute (RPM). You don’t need much in the way of hardware, this version uses an Infrared beam to measure fan speed. As with last year’s PIC-based tutorial, [Chris] is using a character LCD to output the reading. Wiring and driving the LCD ends up being the hardest part.

An IR transmitter/receiver pair are positioned on either side of the fan. When the blade passes in between then, the receiver shuts off a transistor connected to one of the Arduino’s external interrupt pins. He shows how to use this interrupt to measure the amount of time between the passing of each fan blade. If you divide for the number of blades, and average the reading for greater accuracy, you can easily calculate RPM.

Another alternative would have been to use a reflectance sensor which allows to for the transmitter and receiver to both be on the same side of the fan.