One thing that annoyed [Jashua] to no end was hearing his automated sprinkler system kick on in the middle of the night, when it had rained earlier in the day. He wished that his sprinklers were a bit smarter, so he decided to give the system an upgrade.

Rather than pay hundreds of dollars for a more sophisticated automation system, he spent about $45 on supplies and scrounged together some items he had sitting around the house to make a rain-sensing module of his own.

The resulting project, Pysprinklers, uses Python along with a handful of components to better manage his water usage. He got his hands on a cheap rain gauge, and modified it with a game controller and a set of magnetic surface contacts. If there has been a significant amount of rain in the last 24 hours, his system will prevent the sprinklers from turning on. Additionally, if there is rain in the forecast, the sprinklers will be delayed a bit to see if rain makes its way into the area.

We’re all for saving money (and water), so we think [Jashua’s] system looks great, especially because he ended up using a handful of things he already had on hand.

Since he was a kid [Giorgos Lazaridis] has always loved the idea of having an electronic door locking mechanism, and now that he has the means, he’s decided to construct one for securing the door to his apartment. He calls the project “simple and cheap”, though we’re not sure about the first part. Taking a look at his very detailed build log, you can see that he has invested quite a bit of time and effort into this impressive project.

Buying an off the shelf product was expensive and not a whole lot of fun, so [Giorgos] disassembled his door’s locking mechanism to see how he might be able to actuate the lock electronically himself. With minimal modifications to the lock, he was able to add a servo which reliably opens the it when triggered.

With the mechanical portion of the project out of the way, he spent a great deal of time working on the door’s electronic components, including the PIC-based controller and capacitive keypad. The keypad proved to be a bit of a problem, but after a few revisions he found a design that was both reliable and pleasing to the eye.

The locking mechanism works pretty well, as you can see in the video below, and [Giorgos] is quite pleased with the results.

[BrianH] decided that he no longer wanted to venture outside on cold or rainy days just to check if the mail had come, so he built himself a notification system that would alert him if the postman had stopped by. Additionally, he admits to being forgetful on occasion and wanted a way to monitor whether or not he forgot to close the garage door. His Instructable details how he accomplished both of these tasks with the household monitor he built around an ATmega168. His project uses a mailbox mounted photoresistor to determine when the mailbox has been opened, and a reed switch that is triggered when the garage door has been opened. If either of these things occur, a beep is emitted from his notifier, and the appropriate status LED is lit. Simply monitoring whether the garage door has been opened is not all that helpful, so he programmed his notifier to beep persistently at 10-minute intervals if the garage has been left open for more than an hour.

His hack is pretty useful, but he does mention that there is an inordinate amount of wiring that needs to be laid, citing his driveway repaving as a great opportunity to do so.

[Aleksander Zawada] makes vacuum tubes in his home. One of the most challenging builds he has taken on is to produce a working Nixie tube. He describes the process in a PDF, covering his success and failure. It seems the hardest part is to get the tube filled with the proper gas, at the proper pressure, and firmly seal it. In the end he managed to make a tube with three digits (0, 1, and 2) that worked for about 700 hours before burning out.

[Aleksander] joins [Jeri Ellsworth] on the short list of hackers who can pull off extreme industrial manufacturing at home. Kudos.

[Thanks Duncan]

[Jeri Ellsworth] made this silicon inverter at home, by hand. It took her two years to get the process figured out and achieve something we didn’t think was possible. The complexity of manufacture, and the wide range of tools and materials needed seem insurmountable but she did it anyway. Her home chip fab Flickr set is well commented and details her work area and part of the processing. If you’re hurting for more check out her 40 minute Metalab talk which we’ve embedded after the break.

If her name sounds familiar but you just can’t place it you may know her from The Fatman and Circuit Girl. We’ve also featured some of her hacks, such as her Pinball challenge against [Ben Heckendorn], and her giant Etch-a-Sketch.

[Thanks Deyjavont]

Why settle for the standard home icon on your browser? If your home button brings you to hackaday.com, why not make the icon reflect that destination? This hack is quick and simple. We’ll take you through it using Firefox 3 and the default theme with standard sized icons.

We start by using our favorite graphics program to make an icon that is 24×24 pixels, and then saved is as a PNG file without compression.

To use the new image as a home icon, we edited a Cascading Style Sheet which is stored in the file classic.jar. On Ubuntu 9.04, this was found in /usr/lib/firefox-3.0.13/chrome/ but the file will be located elsewhere on other operating systems. We made a backup of classic.jar and then unzipped the contents (JARs are basically the same as zip files).

In the unzipped archive, we navigated to the folder /skin/classic/browser/ and opened browser.css using a text editor. This is where the magic happens and although we only changed the home button icon, there’s a lot more possibilities you should look into. We changed the #home-button entry so that the image URL pointed to our new file using the file:/// format. Here’s what ours looked like after the change:

#home-button {
 list-style-image: url("file:///path_to_our_icon/hackaday-icon.png");
}

We saved this file, then zipped up the file structure back into a file called classic.jar and copied it to the same location we originally found it. A quick restart of Firefox showed the new icon. Let us know your other Firefox tweaks in the comments!

Update: [Colby] pointed out that this type of CSS change should be made in the “userChrome.css” file. He’s right and here’s how:

Find your user profile directory and go to the “chrome” sub-directory inside of it. Create the file “userChrome.css”;  there may already be an example file that you can just rename.  The important bit of this CSS file is the namespace line that tells Firefox how to use it.  Here is what ours looks like:

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* set default namespace to XUL */

#home-button {
 list-style-image: url("file:///path_to_our_icon/hackaday-icon.png") !important;
}

In order to get Firefox to listen to our new icon we had to had the “!important” keyword. Now just restart firefox and bask in the glory of your new home icon.

[Kenneth Maxon] is a wizard who only does things one way, beautifully. While out of the average hacker’s production capabilities, his injection molding machine is amazing to behold. The machine has all features a commercial model would. It heats and cools the mold, produces over a ton of pressure to inject plastic with, and ejects parts automatically to name a few.

[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.

Last week Sony launched the public beta of Home, their virtual world for the PlayStation 3. It wasn’t met with much fanfare and has proven to be quite buggy. Many were less than charmed by scarcity being ported to the virtual world. Others took it upon themselves to hack the service. Connections between the user’s home console and Sony’s server are unencrypted. You can sniff the requests and responses off the wire and modify them live. It seems you need the console to establish the initial connection, but after that you’re free to use builtin tools like Download.jsp, UploadFileServlet, and Delete.jsp to modify any file on the host server. You can also set up a proxy server to modify content, but that will only affect what your console sees.

[photo: nic0]

[via Joystiq]

To replace the old door strike with our new electric unit, we had to align it with the old one. Once it was set, we traced around the mounting plate with a pen and got to work. We grabbed a 3/8 inch bit and drilled out the width and depth of the hole to match the body of the strike. Then we cleaned up things a bit with a wood chisel until the hole was just big enough. The strike requires 12 volts to release, so we had to feed some wire to it. We dug up a fairly long drill bit and drilled through the wall and into the strike mounting hole.

The strike wiring is low voltage, so the wire doesn’t have to be anything special. We used some 18 gauge speaker wire – it’s cheap and we already had it in our parts bin. Pulling the wire is pretty easy. Just feed the wire through and grab the end with a pair of needle nose pliers. Since we had 50 feet of wire to work with, we pulled the wire over to our bench and did a quick soldering job to the strike leads. Once the connections were solid, we insulated them with electric tape. There’s no polarity to worry about, so just get things connected and ready to rock.

The strike has a thick mounting flange, so we had to remove some wood from the surface of the door frame. After some quality time with a hammer, flat headed screw driver, and a wood chisel, we managed to cut a decent mounting slot. Once the wiring was insulated, we pulled in the slack and mounted the strike with a pair of three inch screws.

We’ll be wall mounting the keypad, so we picked up an “old-work” two gang electrical box and a two gang blank wall plate. Mounting the box is pretty easy, but we’ll walk you through it.

To make the bezel, we laid out the buttons in CorelDraw and scaled up each button by a few percent. Once the size was correct, we rounded off the corners to match the buttons better.

After a few test fits made by cutting paper, we put the wall plate into our ever handy laser cutter. We realize that most of you don’t have one of these awesome machines – you can create your own with some careful drilling and dremel work (it might be easier to bribe the local sign shop with some beer). If you do have it laser cut, make sure you get a nylon wall plate and not a PVC plate. The fumes from burning PVC are toxic and air filters will not neutralize them.

When we test fit the new bezel, we found that the flex at the base of each button was impeded. It’s hard to see here, but the wall plate is only about 1/32 of an inch thick. Since it’s so thin, the buttons stick out too far.

To solve both problems, we created a sub-bezel. We used the same laser template, but expanded each hole a bit further. The 1/8 inch acrylic provided perfect depth for the buttons and the larger holes in the sub-bezel provide an area for the buttons to flex.

“Old-work” boxes are designed to be installed into existing drywall. You just have to cut a hole for the box and when the screws are tightened, these tabs will flip up to grip the inside of the wall.

Once the hole’s cut, just insert the box and check the fit. Don’t tighten the screws just yet – we’ll be pulling it back out for a quick mod. Since we’re mounting all the hardware on the other side of the wall, we drilled a hole into the workshop side to run the keypad wiring.

It just happens that Spark Fun’s PC Board is the same width as the 2 gang box. In order to fit the bezel flush, we need to trim back the edge of the box.

You can use your favorite tool, but we grabbed our rotary tool and a small drum sanding bit. Then we ground the edge of the box down to allow for approximately two times the thickness of the keypad PC board. (You might want to adjust this depending on your bezel design.)

The final fit is just about perfect. The edges of the drywall keep the board from shifting while the box supports the board from behind.

Now that the bezels are ready to go, mark your wiring so you can identify it post install. We used some colored electrical tape and noted the connections. Since we used Cat-5, you could easily use RJ-45 connectors to add some modularity. We didn’t need it, so we just pulled the wires through to the workshop side.

To finish up the key pad, we installed the PC board, the keypad, the acrylic sub-bezel, and finally the keypad. Everything actually floats under the keypad. The design has worked perfectly for the past few months – with one exception. One visitor pushed too hard and popped the PC board back into the wall box. If needed, you can add a support strut of some kind behind the PC board.

To create a permanent board for the keypad, we laid everything out in Eagle. Since we wanted to try out some interesting etching ideas, we used extra wide traces and expanded the pads to provide plenty of copper.

After making the keypad bezel, we wanted to try some new tricks with the laser cutter. We coated some copper clad PC Boards with spray paint and let it harden for a few days.

To We exported the design from eagle and sent it to the Epilog via CorelDraw. In order to remove all of the paint, we had to run the etching jo
b twice on the laser. Here, the laser is mid way through the second run.

Even after two jobs, a fine residue was still on the copper. Lightly scrubbing the board with acetone (nail polish remover) removed the left over residue. The traces remained intact and the copper was bared for the etching solution.

Radio Shack doesn’t bother to carry ferric chloride anymore, but we wanted local chemicals. We picked up some muriatic acid (hydrochloric acid), hydrogen peroxide, a cereal container air pump, bubble block, and some hose. The acid is readily available at the hardware store. We suggest finding the smaller container – it’s the perfect amount for a one time fill.

Etching the board is the usual show. The bubbles help agitate the solution around the copper and speed up the process.

The finished etch came out pretty decent, if slightly over-etched. Holding the board up to a light is an easy way to check for top/bottom layer alignment. The board was slightly over-etched, but after spending a couple of weeks mucking around with the process, we decided that it was time to get on with it already.

To drill the board, we used a #59 tungsten carbide drill bit. Instead of a drill press, we manually ran our CNC mini mill to drill the board. We only broke one bit and that was when we fat-fingered a direction key.

One more quick check and the board looks perfect. The milling machine made it easy to keep the holes in line for the build.

Finishing the build is pretty easy (the red wire going over the board was a quick design fix). We added jumpers for all of the Arduino connections and soldered the Cat-5 from the keypad directly to the new board. We won’t bore you with step by step soldering pics. If you prototyped the circuit, you should be intimately familiar with the thing by now. If you need some help soldering, be sure to check out our introduction to soldering.

The bezel’s built, the PC Board etched, the circuit soldered, and the keypad’s installed. The only thing left to do is enjoy the new keypad… or develop more code and teach it some new tricks.

We promised to explain the code a bit, so we’ll give you a quick walk through. The meffect keypad code (available here) was written to simplify the keypad routines for the project. The first several lines initialize the various variables we’ll need to make things work. We added comments regarding pin assignment to help simplify wiring and help people change things around as needed.

The code to drive the digital potentiometer comes directly from this tutorial.

The setup() function is run one time when the controller is powered on or reset. Variables are set and i/o pins are set to their initial states as needed.

The loop() function is the never ending loop where the controller will perform a few tasks. The main order of business is to read the button states for input. Second, the potentiometers are set and each LED is lit temporarily, based on the values in the matrix defined for each LED state. If no action is detected, then the values are set by an effect function. However, if an action is detected, the effect is halted and the button color is set based on the number of inputs keyed in. Next, the loop counts all the button presses that are detected. If the lock exceeds the defined number (in this case, 20) then the pad glows red, state is reset and it locks the user out for about 30 seconds. The final test is the actual lock code. If the keypad state matches the predefined code, then the pad glows green and the door lock is opened for about 5 to 10 seconds.

The code is pretty simple, but the framework is there to produce a more secure lock. The easiest way to up your security would be to create a rolling fade effect and possibly blip the LED color when a key press is detected. Probably the coolest feature of the lock is that you can program it to behave and lock in any way you want.