[Tom Lee] and his colleagues of Sunlight Labs just moved to a new office. The doors are setup like a security checkpoint with electronic strikes and buttons on the inside to allow entry. The button simply completes a low-voltage circuit, activating the strike which made it quite easy to patch into. They build an interface board with a small relay to complete that circuit. As we’ve seen before, Linksys routers have plenty of extra room in the case so there was no problem housing the new circuit in this tiny network device. Now [Nicko] and his friends can use a custom app to input an access code or to verify a device ID from a cell phone and gain entry. The door still has keyed locks in case of a power outage. In fact, the only change made to the system was the addition of two wires to the “door release” button as seen above. See the one-touch device ID authentication in the video after the break.
This hack is similar to the GSM door entry from last year. In this case, the phones are communicating with the door via web interface and not the GSM network.
Will O’Brien at Biobug.org has been doing some cellphone integration work. He recently picked up some Motorola c168i cellphones from eBay. It turns out there is a serial port that uses TTL communication with a standard head-phone jack as an interface. [Will] soldered up a connector and used a USB to FTDI cable to interface with the phone. To his surprise he was able to read off the stored text messages even though they were PIN protected in the phone’s operating system. The messages on these units were trivial but this is another example of the importance of clearing your data before discarding your devices.
Since there’s almost any size and shape of solar panel available for purchase from a myriad of vendors across the Internet why would anybody want to go through the hassle of tabbing together their own cells to build a solar panel? Because you can, obviously. This DIY video will run through the basics of chaining together polycrystalline cells and leaves the details like enclosure and such to the user.
The Cheap Vegetable Gardner wanted more automation than their previous PS2 controller based grow system. This time they set out to design a full featured, compact grow controller that can measure temperature and humidity as well as control a heat lamp, fan, and water pump. An Arduino provides USB connectivity and interfaces the solid state relays and sensors. The assembled project all fits in a box but we are left wondering how much heat the four SSRs generate and will it be a problem?
This is a classic example of a well done hack, simply for the sake of hacking. [Jorge] wanted to be able to chart his weight changes. His solution wasn’t to simply buy a scale that could be hooked to the computer. Those are available and aren’t really that expensive. He could have even used pencil and paper to chart it in a few seconds. Instead, [Jorge] started hacking. He took apart a digital scale he already had and installed his own circuit to display weight and write the values to a CSV. The CSV resides on a removable card which can then be put in his computer to chart the data in openoffice.
Have a room in your house that really could benefit from some sunlight? Build a Suntrack to reflect light in as long as possible. The two axis motor set up is built from a couple of satellite dish positioning motors with the control electronics removed. The whole thing is controlled with a PIC 18f2520. Once calibrated, it will reflect the sun into your room, updating every twenty seconds. While this may not be the most efficient way of lighting a room, it is a cool way to do it if you absolutely must have sunlight. We can’t help but wonder if there would be a way of using a solar powered system to do this to save energy. Could this possibly be done using BEAM “head” circuit?
[Josh] sent in a home automation project he did a little while ago. It has a total of eight switched outlets. The main focus of the project was WAP access for remote control from any cellphone. The control box is based on a design by [Ashley Roll] for controlling eight servos using a PIC microcontroller. A listener app written in Java monitors the control web page and sends signals to the board via serial port. He used opto-isolated 240V solid state relays for each of the outlets. All the pieces are available on the site and he might even do a custom control board design if there is enough interest.
In the vein of Arduino-controlled espresso machines and Lego bots, we’ve been playing around with Flash and the Nokia 770 Internet Tablet. With its flexible Linux-based OS, the Nokia 770 is great for rapid prototyping. Plus, you can snag one on the cheap ($65-170 on eBay).
Hardware aside, Flash is a great language for quick prototyping. It’s an environment that many designers are already familiar with, and it enables the user to create a graphic interface in minutes. For prototyping on small screens, Flash Lite can be used, but Flash Lite cannot communicate to other devices outside of the device it’s running on (aside from calling other phones). The Nokia Internet tablets are interesting because they are essentially tiny Linux computers and run full-fledged Flash. We got one of these tablets to run Flash and talk to an Arduino board. This enables any kind of sensor to communicate with the Flash application and allows the app to control things like lights and motors.
Detailed instructions for setting this up can be found in our Google Code wiki (here and here)…
