I remember playing with my Lite Brite when I was young. What looks better than sticking solid plastic pegs into fixed holes in a grid of plastic? The answer is the beautiful glow of individual LEDs soldered into a perf board! There is of course some added complexity that comes with that choice. These days I am answering lots of questions on LED applications from our LED customers, what resistance should be used, what voltage should be used, what is the ideal current for a certain application, what series parallel combination should be used, etc. A LED resistor calculator helps but is still not super simple for all end users. That’s what makes these Hi-Tec Sketch Art products shine! All you do is pick up an LED with the desired color and stick it in the special pad. Keep sticking LEDs in the pad until your design is done. 

The model pictured above is the Hi-Tec Sketch Art model.

Ever wonder how those cheap devices at Walmart sense you walking by so they can play the cricket sound or meow like a cat? Have a look at the circuit for these Spooky Halloween Eyes for some details. A slight change in ambient light is all it takes for the small device to "see" that someone is close.

"The schematic is quite simple, each of the devices (LED’s, phototransistor, sounder) are simply connected to the appropriate uC pin. The phototransistor is biased by a single 499kohm resistor. This seemed to give a nice range of resulting voltages in the low light levels expected during operation. Triggering is done using by detecting a change in illumination, not an absolute threshold, thus this should provide nice performance."

Hans Scharler has been busy making a DIY Steampunk Pumpkin that is sure to please anyone who sees it. He squished tons of parts in there from some of the best DIY providers. His own ioBridge, some sensors from Adafruit, some ThingM (designed by Tod Kurt) parts from Sparkfun.

"Using the ioBridge IO-204, I rigged up the fog machine to trigger when someone walked in front of the pumpkin. I used a passive infrared sensor from Adafruit to detect motion. The IO-204 has an upcoming feature that allows for on board logic, meaning you can break off of the Internet and have local controls take over. To integrate it with the fog machine, I tapped into the wireless remote control that came with the fog machine. This made it easy to control using a single relay. To light the pumpkin, I bought a BlinkM RGB LED Blaster from Sparkfun. The LEDs are high intensity lights that you can mix colors together."

If you played with a Meccano set when you were younger as I did this MicroRAX mini T-Slot Construction system may bring back some of those construction ideas. I have seen a larger version of this system used in industry for constructing modular systems that are very rigid and simply to modify. It looks like it could be an ideal solution to building a robot platform where the end result is more of an evolution than a set construction plan.

Update. I forgot to mention that MicroRAX is giving away some free samples, this will allow you to have a look at the product before you buy. The free sample is probably time limited so act now, pass this along to your mechanical engineering friends so that they can learn about this product also.

Via: Hacked Gadgets Forum

"MicroRAX a light weight miniature T-Slot building kit. Suitable for use on your desktop or bench top to build science, engineering, or advanced hobby and DIY projects. This small rugged framing system is ideal for use in machines, school science projects, robotics, design houses, workshops, prototypes, repair, models, gadgets, maintenance, etc."

Our friend Carlos Asmat has built a Panoramic Camera with lots of build details. You can find the code that runs the system here and more results of the camera system here. 

"Materials

• Hitec HS-785HB Winch Servo Motor
• ServoCity SPT200 Direct Drive Pan & Tilt System
• Pololu Micro Serial 8 Servo Controller
• Hitec HS-425BB Servo Motor
• A digital camera
• Small plastic container
• Battery holders
• (Rechargeable) Batteries
• A piece of aluminum (I used an old heat sink)
• A long nut (of the same size as a tripod screw)
• A screw (that fits into the tripod attachment on the camera)
• A tripod
• Cable ties
• A small piece of neoprene (or any other mushy substance)
• A USB to Serial cable
• Some female headers and wires"

Here is my latest creation, it’s a Gear Clock. It consists of a bunch of wooden gears, a PIC microcontroller and a stepper motor. The heart of the clock is a PIC 16f628A microcontroller. This microcontroller has an internal oscillator however an external 20MHz crystal oscillator is being used since it will have to accurately keep track of time for weeks and months. The microcontroller is interfaced to two buttons and one motor.

The gear arrangement is as follows:

• 9 tooth motor gear
• 72 tooth minute gear with a 24 tooth secondary
• 72 tooth intermediate gear with a 18 tooth secondary
• 72 tooth hour gear

To achieve the correct timing the 9 tooth motor gear is advanced 4 steps every 9 seconds. By moving 4 steps at a time the motor routines can be simple since the motor is always at rest with the same coil energized.

Read more about the gear clock here.

Bob Davis has made another can crusher with a huge 5 thousand volt power supply eBay score. A 100uF capacitor doesn’t sound that big, heck I have ones that are 10 times that size in a tray right beside me as I type this. Well the big difference is the one that is beside me has a voltage rating of 50 volts. That is a far cry from the 5000 volt rating that the one in this power supply! We have featured a bunch of Bob’s can crushers here in the past but I think that this is the biggest and baddest one so far!