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.

Improving Headphones By Voiding Warranties

February 5, 2012 by Brian Benchoff 34 Comments

[Dan] had been wanting a pair of Bluetooth headphones for quite a while. Most of the reviews for wireless headphones in the $50-$80 range complained of tinny sound and dropped bass. Nevertheless, he stumbled upon a $20 pair of headphones with similar reviews and realized that he could switch out the driver and make a decent pair of cans.

The donor drivers came from a pair of Sennheiser HD 540 headphones. These are very respectable headphone speakers that cost about what you would expect for pro audio gear. To to get Bluetooth working with the Sennheisers, [Dan] removed the PCB and battery enclosure and attached them to the headband with velcro.

For his build, he had to cut the cable on the Sennheisers and solder them to the Bluetooth board. There was never any danger of ruining a good pair of headphones, though. If he screwed up he was only out a headphone cable. Now [Dan] has a nice pair of Bluetooth headphones that can reproduce bass. Not a bad deal for a $20 pair of headphones.

Remote Entry Via Android And Launchpad

January 24, 2012 by Kevin Dady 8 Comments

[MarkoeZ] had an issue with keys breaking off in his door lock, and while normal people might try to simply replace the lock all together, [MarkoeZ] decided to do it the “Hackaday” way by adding a bluetooth lock to his door. His door is already setup where someone can walk up to it, page an internal intercom and have someone buzz you in. From the inside the intercom was modded with a TI Launchpad with a “deal extreme” bluetooth module and relay.

Access is granted by the use of an android phone running “BT_Serial_Tester” which is a simple app that allows you to send characters over bluetooth. Just enter a pin, grab the door before the buzzer times out, and you’re in! A starting point for the MSP code and schematics are available on his blog. Join us after the break for a quick demonstration video.

Continue reading “Remote Entry Via Android And Launchpad” →

Controlling A Cute Ikea Night Light With Android On The Cheap

January 19, 2012 by Brian Benchoff 12 Comments

When [trandi]’s wife saw a cute night light at Ikea, she had to have it. She actually bought several of these for when her husband would inevitably crack one open and start tinkering with the microcontroller inside. The inevitable hack is pretty cool, and also gives us some ideas for interfacing with Android on the cheap.

The build started as an Ikea Spoka night light, an adorable anthropomorphized night light with a squishy silicone skin. Inside the Spoka are a dozen tri-color LEDs that [trandi] can cycle through with the push of a button. After deciding to control the lights inside the Spoka with an Android phone he reached for an IOIO Android breakout board. Fate intervened and [trandi] ended up with a ridiculously cheap Bluetooth modules that provides a simple serial connection to other Bluetooth devices.

The build reuses the blue, red, orange LEDs in the night light but replaces the no-name 8-pin micro with an ATtiny2313. [Trandi] wrote a small Android app to control the color over a Bluetooth serial connection. Check out his demo after the break.

Continue reading “Controlling A Cute Ikea Night Light With Android On The Cheap” →

Over-engineering A Two-zone Thermometer

January 4, 2012 by Mike Szczys 6 Comments

We love the extra touches that [Andrianakis Haris] added to his two-zone electronic thermometer. It includes features that you just wouldn’t find on a mass-market commercial product because of issues like added cost. For example, you can see that the PCB juts up above the LCD display, allowing the module to be mounted on a pair of screws thanks to the keyhole shape that was drilled in the substrate. I increases the board size greatly, but on a small hobby run this won’t usually affect the price of the board depending on the fab house pricing model.

The design uses an ATmega8 microcontroller to monitor sensors in two different places. There is an onboard LM35 temperature sensor for monitoring the space where the unit resides. A remote sensor module uses a DHT-11 chip to gather data about temperature and humidity. That sensor is wired, but there is one wireless option for the device. Data can be pulled down from it via an optional Bluetooth module which can be soldered to a footprint on the back of the board.

Check out the video after the break to see temperature readings pulled down wirelessly. Continue reading “Over-engineering A Two-zone Thermometer” →