Transit pass controls this home security system

[Folkert van Heusden] installed a bunch of cameras in and around his home. Ostensibly this is for watching the kitties from work, but we’re sure the more accepted purpose is for security. He and his wife don’t really want the cameras rolling when they’re at home. So he added a system by the front door with uses a transit pass to turn on and off the security cameras.

The pass is an RFID tag which gets them on the subways, trains, and buses around the Netherlands. To use it with this system he needed an RFID reader. The one he chose is a USB device which enumerates as an HID keyboard. When it detects a valid card it outputs the tag id as a string of characters. [Folkert's] setup uses an eeePC with a broken keyboard to connect to the reader. A perl script monitors the feed from the reader, and verifies each code as it is received. After authentication the script will enable or disable the networked cameras and update the LED readout accordingly. To keep everything hidden he put it in the closet, using a hole (from a doorknob?) as a wire pass-through.

Automated home brewing system has an insanely professional controller

So you know how on Breaking Bad, the chemist [Gale Boetticher] sets up an impressive rig to brew the best cup of coffee? Well what do you think of a group of engineers taking on beer as their side project? This rig, which we do think is pretty insane, is the result of embedded system engineers developing an automated brewing system.

[Ben_B] started from humble beginnings. He built a PID controlled smoker much like the one we saw last Monday. From there he ground out several iterations of brewing hardware, adding a bit of automation at each step along the way. But things really took off when the events department at his company, National Instruments, took notice. They put the team on the task of assembling professional grade control hardware for the unit. And of course while we’re spending the company dime why not chrome those boiling vessels at the same time. The finished project was shown off at a trade show to help promote the company.

The post thread linked at the top has shots of the complicated mounting and wiring that went into the controller. We’re not sure how much intervention is actually necessary during a session. But with all the sensors, pumps, valves, filters, and whatnot we wouldn’t be surprised if all you need to do is pitch some yeast into what comes out of it.

Wiring up a lot of LED segment displays

One look at this display and you know there’s a whole lot of pins that need to be wired up. Now look at what those display modules are mounted on. That’s right, [Kemley] is using point-to-point soldering to rig up this big display. It sports four sixteen segment modules on top for alpha-numeric information, and eight large seven segment modules for displaying numbers only.

We’re not certain as to how the electronics are arranged. When talking about the 16-segment modules he mentions that all four are in parallel with NPN transistors to switch the common anode of each. That’s easy enough to understand. But when you get a look at the transistor board you’ll see 24 of them in use. He’s included a 150 ohm resistor on the collector of each transistor. It must be set up to only allow one segment of each group to switch on at a time? We’d guess that each segment is divided into two (upper and lower pins are multiplexed separately), which would explain the double set of transistors. As for date and time, an Arduino board monitors a DS1307 RTC and manages the scanning of the display.

NES light gun gets a burning laser upgrade

The Nintendo Light Gun makes a perfect burning laser. Of course it’s been gutted to make this happen. Nonetheless, the retro look can’t be beat, and the gun form factor is just what you need in a laser weapon.

This will literally burn your eye out of your head, so [Justin] and his buddies over a North Street Labs are all wearing protective goggles designed for this laser’s wavelength. But they also built a safety into the zapper itself. At the beginning of the video clip (embedded after the break) you will see there’s a key lock mounted in the butt. This lock completes the circuit between the battery and driver board. The 2W output is achieved by a 445nm M140 diode. A lot went into the heat sink and mounting cylinder to make sure the diode doesn’t just burn up after a few seconds of use.

[Read more...]

Galaxy SIII hack puts Android in your dashboard

Here’s how you can have a hands-free, no worries about the battery, Android experience while you drive. [Steve] removed the head unit from his car and replaced it with a Samsung Galaxy SIII Android phone. The look is pretty nice, but we do have a few suggested improvements if you try this one for yourself.

It started simply by removing the factory stereo which left a double-height opening in the dashboard. [Steve] cut a piece of wood to fit the gaping hole, painting it a grey that would compliment the interior colors of the car. The phone is mounted on this plate, with plenty of room for the USB and audio cables. From there it is finished up with another wooden plate which has a cutout for the touch screen. See the final project, as well as glimpses of the installation, in the video after the break.

[Steve] demonstrates using the GPS features and playing music. We’d improve this in a couple of ways. First off, using something like the IOIO board you could add a physical volume knob, which we’re not interested in giving up for a touch screen quite yet. If you were willing to go the extra mile, a CAN-BUS chip could be added too that would monitor button presses from the steering wheel music controls.

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Classic game of Snake on an ARM controller

Every now and again we take a break from looking at all of your awesome projects and get to work on our own. I thought I’d take a minute to show off my game of Snake. It’s a classic that I remember playing on a graphing calculator (TI-83) back in high school. I had never written my own version and decided it would be a good reason to spend some more time on the ARM platform.

The dev board I’m using is the STM32 F0 Discovery board. Once I had a usable template for compiling the code on a Linux box everything else just started to fall into place. The screen is from a Nokia 3595. Several years back I cut off the keypad and made a breakout board for it. It’s pretty dim but it’s small and uses SPI so it tends to be my go-to display for prototyping. But I did get my hands on an SSD1289 TFT screen (after writing about this project) for about $16 and I’ve had some success with that. It uses a parallel interface so it’s not as easy to hook up and I’ve had some crosstalk issues when running at 24 MHz.

But I digress. Check out the demo video of my simple game after the break. There are more details about my programming choices at post link above. You will see this hardware again soon. I’m working on an On Chip Debugging primer and these ARM dev boards are perfect for it!

[Read more...]

Hackaday Links: September 21, 2012

And then Obi-wan said, “you were supposed to be the chosen one!”

Yesterday, a little bird told us Makerbot will be moving to a closed source model for their newest printer. This was confirmed, and now [Zach Smith] a.k.a. [Hoeken] – creator of the RepRap Research Foundation and co-founder of Makerboth Industries is weighing in with his take on the situation.

Hey! Free stuff!

Remember that DIP28 ARM chip with BASIC? Remember how I told you Coridium will be giving a few hundred away as samples? Yeah, that’s happening now.

Replacing a scroll wheel with titanium

[Rhett] has been using a Logitech mouse for a few years now. Recently the scroll wheel became corroded, so [Rhett] replaced it with a titanium version. The perfect match for the trusty battle axe, theIBM Model M keyboard.

Web-based IDE for the Raspi

[Phil Torrone] sent in a video of something he and [ladyada] are working on. It’s a web-based IDE for the Raspberry Pi. We’ll do a full review of this when it’s released.

Intro to software defined radio

So you have one of those TV tuner dongles and want to get in to software defined radio. Where do you start? [Al Williams] over at Dr. Dobbs has a great introduction to SDR, and gives a few pointers that should help you get that cool looking waterfall plot very quickly. Thanks for sending this in, [Chris].

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