Finding Your Keys With Bluetooth

April 23, 2012 by Brian Benchoff 28 Comments

[doragasu]’s wife is always misplacing her keys. To solve this problem, [doragasu] created a small Bluetooth-enabled key fob that is able to remotely sound an alarm when commanded to by a cell phone.

The case and LiPo battery of [doragasu]’s project comes from a small photo frame key fob. The LCD display and PCB of the photo frame were tossed aside for a future project, and the design of the circuit started. The Bluetooth buzzer key fob is based around an MSP430 microcontroller because of their extremely low power requirements.

On the software side of things, [doragasu] built a J2ME app to connect to the key fob and turn the buzzer on. His app is portable to any Android phone, and versions can be ported to Windows, OS X and iOS devices.

How does it work? Well, [doragasu]’s wife sometimes forgets to charge her key fob, rendering the whole project useless. There are ideas for updating the device to a Bluetooth 4.0 Low Energy device, but no actionable plans. Still, very good work. You can check out [doragasu]’s walkthrough and demo video after the break.

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Fifty Dollars To Make Your Car Audio Bluetooth Compatible

April 18, 2012 by Mike Szczys 11 Comments

We’re rather impressed with the work [Aaron] did to add Bluetooth connectivity to his 2008 Honda. He used an aftermarket kit, but rolled in his own revisions to make it look and feel like an original feature.

After being disappointed by an expensive docking system he grabbed a Jensen BT360 kit for about $35. It comes with an external speaker which would look horrid mounted on the dash. That speaker is meant to play your telephone audio via Bluetooth, while music from the phone is sent to the car stereo using an FM transmitter. Since he planned on hiding the control unit under the dash anyway, it wasn’t too hard to add some wires which intercept the audio being fed to that FM transmitter. From there he added a couple of relays to automatically route the audio signals (when present) and patched the whole thing into the Aux input. This way he doesn’t need the extra speaker, and all sound is feed to the head unit via wire instead of radio transmissions.

The final setup works pretty well. If a phone call comes in it automatically mutes the volume, or pauses the iPod if that’s what’s currently playing through the Aux port. [Aaron] thinks the bass from music played via Bluetooth is not quite as rich as when using the Aux port, but if you don’t mind the cables that’s still an option too.

Communicating From Anywhere With A SPOT Connect

April 17, 2012 by Brian Benchoff 11 Comments

[Nate] over at Sparkfun put up a great tutorial for using the SPOT personal satellite communicator with just about any microcontroller. These personal satellite transmitters were originally intended to pair with the bluetooth module of a smart phone, allowing you to send a short 41-character message from anywhere in the world. Now, you can use these neat little boxes for getting data from remote sensors, or even telemetry from a weather balloon.

[Nate]’s teardown expands on [natrium42/a>] and [Travis Goodspeed]’s efforts in reverse-engineering the SPOT satellite communicator. The hardware works with the Globalstar satellite constellation only for uplink use. That is, you can’t send stuff to a remote device with a SPOT. After poking around the circuitry of the original, first-edition SPOT, [Nate] pulled out a much cheaper SPOT Connect from his bag of tricks. Like the previous hacks, tying into the bluetooth TX/RX lines granted [Nate] full access to broadcast anything he wants to a satellite sitting in orbit.

We’ve seen the SPOT satellite messaging service put to use in a high altitude balloon over the wilds of northern California where it proved to be a very reliable, if expensive, means of data collection. Sometimes, though, XBees and terrestrial radio just aren’t good enough, and you need a satellite solution.

The SPOT satellite service has an enormous coverage area, seen in the title pic of this post. The only major landmasses not covered are eastern and southern Africa, India, and the southern tip of South America. If anyone out there wants to build a transatlantic UAV, SPOT, and [Nate]’s awesome tutorial, are the tools to use.

Tip ‘o the hat to [MS3FGX] for sending this one in.

Poking Machine

March 14, 2012 by Brian Benchoff 14 Comments

We may be showing our age here, but we have no idea what a ‘poke’ on Facebook actually means. Whether it’s the passive-aggressive manifestations of online stalkers or an extension of the ‘like’ button, all we know is [Jasper] and [Bartholomäus] built a machine that translates virtual pokes into our analog world.

The “Poking Machine” as [Jasper] and [Bart] call it, syncs to your phone over a Bluetooth connection. The build is incredibly simple: just an ATtiny running Arduino for ATtiny, a Bluetooth controller (possibly this one from Sparkfun), and a servo. When the Facebook app on [Jasper] and [Bart]’s phone receives notification of a ‘poke’, the servo is powered and gently taps the wearer on the arm.

One thing we really like about this project is the case made of several layers of laser-cut acrylic bolted together. This case offers a very clean look even if it is a bit ungainly. We suppose the guys could have used a simple vibration/pager motor for this build, but it wouldn’t exactly be a poking machine at that point. Check out the build video after the break.

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Control An Arduino From Android Over Bluetooth

March 13, 2012 by Brian Benchoff 10 Comments

Whether you’d like to do some real-time logging of data, or just want to control a project with your Android phone, [Thomas]’s Arduino-Android Bluetooth connection instructable is sure to be useful

[Thomas]’ build uses the very inexpensive JY-MCU Bluetooth module that’s available on eBay or dealextreme. This Bluetooth module ties directly into the Tx and Rx lines of the Arduino so a wireless serial connection between an Android device can be established. On the Android side of the build, Python for Android and the Scripting Layer for Android allow for reading wireless sensor data over Bluetooth.

While connecting an Android device to an Arduino is also possible with an IOIO or an Android Open Accessory dev kit, we haven’t seen much (barring this) about controlling or reading simple electronics with Android over Bluetooth. Sometimes you just don’t need an awesome dev board to bodge up a simple project, so we hope [Thomas]’s very nice instructable will help get a few more builds off the ground.

Wireless Solar Water Heater Controller Ensures Hot Water Every Time

March 9, 2012 by Mike Nathan 8 Comments

water-heater-controller

[Peter Sobey] had a solar hot water heater installed in his home, which worked great until he relocated his kitchen to a neighboring room. Now a good bit further from the tank, the hot water reaching his sink was tepid at best due to the increased distance and temperature limiting mixer valve in the new heater.

He installed a salvaged solar panel and water tank solely for use in his kitchen, but as the panel was located above the tank, he had to find a way to actively monitor and control the water temperature. His pump and valve system was originally driven with an off the shelf PICAXE-based controller, but he eventually got the urge to add a wireless display and control panel to the mix.

A pair of Arduino Nanos run the show now, one of which resides in the pump controller box, while the other is used in the temperature display box in his kitchen. He uses a set of Bluetooth modules to link the Arduinos together, relaying temperature data and allowing him to send the pump controller manual commands if needed.

He says the system works a treat, and he’s much happier with his homebrew controller than the one he used originally.

Connecting A Dumb Scale To Your Smartphone

February 13, 2012 by Mike Szczys 6 Comments

[Casainho] wanted to track his body weight using an app on his Android phone. He just needed a way to get the weight readings onto the device automatically. He ended up adding Bluetooth to a bathroom scale and hacking the app to grab data from it.

The scale which he hacked is a digital model, which makes it possible to read the weight data if you know what you’re doing. [Casainho] already completed a weight logging scale hack which stored the data on an SD card. So this was a recreation of that project but with a Bluetooth module for the output rather than the card for storage.

Now you can buy WiFi enabled scales, but that’s not nearly as fun as a hack like this. Plus one of those will cost you around $200 and the hardware for this version came it at only $75. It includes an LPC2103 dev board, $6 Bluetooth module, character display, batteries, and misc. supplies. The software end of the hack was helped greatly by the fact that the Android apps which [Casainho] is using are both open source.