Charging Timer For R/C Batteries

February 4, 2011 by Mike Nathan 27 Comments

arduino_controlled_socket

Santa brought [Quinten’s] son a shiny R/C truck for Christmas, but this new toy had one drawback – its batteries could only be connected to the charger for a maximum of 6 hours, lest he turn his house into a pile of smoldering ash. With grave warnings from the manufacturer dancing in his head, he searched around for a timer that would allow him to cut power to the battery after charging for its allotted time. Coming up empty, he decided to create his own timed electric socket regulated by an Arduino he had sitting around. He grabbed a project box and wired up a nice looking socket timer, complete with an LCD status display. To make things easy for his son, he added two buttons to the front of the controller – one for selecting the amount of charging time, and one to set the timer in motion. As with his previous hacks, [Quinten] has provided plenty of documentation in the form of pictures, code, and even a video of the timer in action.

PID Controlled Smoker

February 3, 2011 by Chris Nelson 14 Comments

[dafonso] purchased a nice 1500W smoker but was somewhat dismayed that it only had one cooking temperature. To compensate he designed his own PID control system which allows him to set the cooking temperature digitally. At the heart of the system is a PICAXE 18 micro which switches the smoker on and off using a solid state relay. Rather than testing the 110V system on the smoker itself (which would have been a pain indoors) he used a lamp instead. To see if he was getting the correct temperature he taped his thermocouple to the light bulb and let the PID switch the lamp on and off. Also be sure to checkout his video which does a good job of explaining how he was able to solder the surface mount components required for the control board.

Building Infra Red Light Sources With Regular Lights

February 2, 2011 by Caleb Kraft 23 Comments

[Oneironaut] sent us another IR hack. This time it is a writeup on the best ways to create IR light sources from regular lights. Since normal flashlight bulbs emit a broad enough spectrum to include visible light and IR light, this basically comes down to filtering. [Oneironaut] explores different light sources and different materials in depth, along with great pictures to show his results. This is a great resource if you’re needing to do some night vision for cheap.

Water-dosing Coffee Maker Augmentation

February 1, 2011 by Mike Szczys 17 Comments

[Arthur Benemann] has the worst part of making coffee licked. His add-on for a drip coffee maker fills the water to the proper levels for you, saving the drudgery of rinsing out the carafe, carefully filling it to the appropriate level, then pouring it into the machine without getting everything wet. This isn’t limited to a full pot, but is user selectable by the cup based on how many times in a row you hit that red button. One LED gives feedback on the selected mode, then the device uses a washing machine water valve to turn on the tap for the appropriate amount of time. We’re a little bit leery of connecting homebrew hardware to the water pipes in our house. Make sure you’ve done a good job of debugging so that an infinite loop doesn’t flood you out.

Out Engineering A Sneaky Cat

January 31, 2011 by James Munns 31 Comments

Cats do what they want, which rarely coincides with what their owner wants them to do. In [Dumitru]’s case, his girlfriend’s cat [Pufu] tended to make it outside into the cold more often than desired. Rather than settle with the normal bell which gets obnoxious even when the cat isn’t misbehaving, he decided to put together a custom Cat Finding collar. He used a PIC microcontroller as the brains, and temperature and light sensors to decide whether the cat had snuck into the cold, dark night. Once the cat has been marked as being outside, a buzzer and LED are set to go off at regular intervals until returned into the safety of the indoors.

[Dumitru]’s website along with his YouTube videos are in Romanian, though the schematics and source code provided speak for themselves. He does a wonderful job walking through the entire design process, including time spend in the IDE as well as EAGLE designing the board. YouTube has managed to subtitle the majority of the details, but we imagine this post will be a real treat to any Romanian speaking hobbyists out there. Be sure to catch both videos after the break.

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Snail Mail Notification System

January 30, 2011 by Caleb Kraft 29 Comments

[Mime] lives on one of the upper levels of an apartment complex. The mailboxes, being located at the ground floor can be somewhat inconvenient to check regularly. [Mime] decided to rig up a device to let him know when his mailbox had been accessed. He started with a wireless doorbell, thinking he could use the door side button inside his mailbox as a trigger with only some slight modification. On the receiver side, he wanted an LED to flash, letting him know that it was time to check his mail. One simple circuit and a self blinking LED later and the whole setup was finished. Great job [Mime]

Reverse Engineering Radio Controlled Outlets

January 26, 2011 by Mike Szczys 31 Comments

[Chr] picked up a pack of remote control outlets in order to reverse engineer them and build control into his own projects. These can be plugged into outlets around your house and a relay inside each module will switch whatever device is plugged into it after receiving a command from the remote. Once he cracked open the control housing it was easy to find the data line for the RF module which was on its own board. He used a logic analyzer to capture data from various button presses and then spent some time deciphering the communication protocol. He used what he learned to roll the module and code into an interface box where an ATmega8 connects via USB and passes commands from a computer to the RF board. Now he’s added home automation via a computer quite inexpensively. After the break you can watch a clip of the outlets switched using a smartphone.

So why not just patch into the buttons on the remote? Well, this same project was attempted at our local hackerspace earlier this month and the buttons don’t just pull a pin to ground. They use tri-state logic and are arranged into a matrix that is a lot harder to mimic (if not impossible) with a microcontroller. Analyzing the communications going into the RF module is definitely the less labor-intensive of the two approaches.

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