A Longboard Speed And Distance Computer

March 4, 2013 by Mike Szczys 17 Comments

longboard-speed-distance-comptuer

Why should cyclists have all of the fancy toys? Bicycle computers are very common these days but you won’t find similar hardware for skateboards and longboards. [KobraX22] isn’t taking it lying down. He built this speed and distance computer for his longboard. It doesn’t use very many components and should be easy to install.

The device monitors the rotation of one of the wheels by mounting a reflectance sensor on one of the trucks. It points toward the inside of a wheel which has a piece of black tape on it. Every time the tape passes it prevents the IR led from reflecting back at its paired receiver. This lets the Arduino count the revolutions, which are then paired with the wheel diameter to calculate speed as well as distance traveled. Of course the wheels wear down over time to so frequent riders will have to take new measurements at regular intervals.

[KobraX22] went with a QRB1114 sensor. It costs less than $2 and doesn’t require him to embed a magnet in the wheel like a hall effect sensor setup would have. It also shouldn’t interfere with any other fancy wheel hacks you’ve done, like adding a POV display.

[via Reddit]

A Solar Powered Cattle Crossing Gate

February 28, 2013 by Mike Szczys 21 Comments

solar-powered-cattle-crossing-gate

Anyone who’s traveled the grounds of a cattle ranch will tell you there’s a lot of stopping to open and close gates. But this project is aimed at letting you operate the gate from the comfort of your vehicle. It uses a spool of wire as the gate, lowering it for vehicle access with the use of a remote control.

The base station uses a solar panel to keep the battery topped off. But if you’re not frequently using the system it shouldn’t take much electricity at all. An Arduino board listens for the signal from the remote control. It then unspools the wire until it lays flat across the ground and can be driven over. Once the car has passed another click of the remote raises the gate back into position. There’s even a version that uses two gates which make up a cattle corridor.

We were thinking that it would be easy enough for the cows to push right through this. But after seeing the clip after the break it’s obvious they like to follow the rules.

Continue reading “A Solar Powered Cattle Crossing Gate” →

Add Some Animated Bling To Your GQ Duds

February 27, 2013 by Mike Szczys 7 Comments

geeky-tie-uses-animated-leds

This tie turned VU meter has us asking: Will anyone be able to look you in the eye during a conversation? It uses an integrated microphone and microcontroller to make a single-column display made of RGB LEDs move to ambient sound.

It shouldn’t be hard to guess that this project is another build from [Becky Stern]. She’s been on fire lately, offering up glowing football helmets and a turn-signal backpack. This uses the same family of components as the latter. A Flora board brings an Arduino to the party. It drives sixteen RGB LED pixels which are addressed using a 1-wire protocol. Sound is measured through a microphone and amplifier breakout board.

Since the hardware gets in the way of a full-windsor, the tie used for the project is a breakaway version which uses velcro. But because you need the needle and (conductive) thread to sew on the components it wouldn’t be hard to alter any tie to perform like this.

Don’t miss the high-quality video tutorial which we’ve embedded after the break.

Continue reading “Add Some Animated Bling To Your GQ Duds” →

Simple To Build Programmable Foot Switches

February 26, 2013 by Mike Szczys 19 Comments

programmable-footswitches

Your hands do a lot of work between the keyboard and the mouse, why the heck are you letting your feet be so lazy? [Dossier van D.] is putting an end to the podiatric sloth. He built this set of three foot pedals which have gone through two versions of functionality.

The buttons themselves are made from a base plate of plywood with a smaller piece on top for each ‘key’. The two parts are separated with some foam carpet pad, with a tactile push button in between to register a click. The only thing we’d change about this is adding a couple of wooden spacers next to the switch so that accidentally sanding on a button doesn’t break that electronic component.

Originally each button was soldered to a gaming controller. This worked just fine using button mapping, but recently [Dossier] made the switch to using an Arduino Leonardo. This is a perfect choice. Unlike input devices made with older Arduino versions the Leonardo board can natively register as a keyboard, making it a snap to programmatically map any key to the switches.

If you like this project you should check out [Dossier’s] foot mouse as well.

Python Frontend Is A GUI For Different Microcontrollers

February 26, 2013 by Mike Szczys 4 Comments

python-frontend-gui-for-microcontrollers

[Navin] has been hard at work producing a GUI which works with different micocontrollers. The idea is to make it even easier to develop projects by simplifying the feedback and control you can get from the prototyping hardware. The best part about it is that he designed the software to interface with any hardware which can be programmed in C++.

The screenshot above shows the program communicating with an mbed board which has an ARM microcontroller. But the Arduino board (which uses an ATmega chip) is supported as well. Support for additional architectures can be added by writing your own configuration file for the chip. The Python program then asks for the com port it should be using for this session.

The source package, including the code which runs on the microcontrollers, can be found at the project repository. The functions used in the sketches are quite simple and should be a snap to drop into your own code projects.

Critter Cam Hacked From An Old Cellphone.

February 25, 2013 by Mike Szczys 22 Comments

critter-cam-hacked-from-old-cellphone

[Art Barrios] kept having night-time visitors who were raiding his dog’s food storage bin. It’s a plastic tub with a lid that latches but the critters were knocking it over and popping that lid off. He wanted to find out which animal was the culprit so he hacked together an automatic camera system using an old cellphone.

You can see the majority of the hardware he used in the image above. There’s an Arduino on the left. This monitors a switch which he added to the lid of the food storage container. It triggers the system when opened, switching on an LED light and snapping pictures.

The touchscreen button is used to trigger the shutter. That’s what all of that tin foil is about. Some experiments led [Art] to realize that a metal ‘finger’ could register on the screen if there was enough foil attached. To move the metal bracket he uses a solenoid. The last problem he faced was keeping the cellphone screen awake. He figured out that power cycling the charger does the trick. The Arduino manages this using a mains-rated relay.

The system successfully captured images of a family of raccoons feasting on the tasty morsels.

Using A Flashing LCD Monitor To Transfer Data

February 25, 2013 by Mike Szczys 76 Comments

lcd-screen-data-transfer We love the concept of using an LCD screen to transfer data. The most wide-spread and successful method we know of is the combination of a QR code and the camera on a smart phone. But for less powerful/costly devices data can be transferred simply by flashing colors on the screen. That’s what [Connor Taylor] is testing out with this project. He’s using a TEMT6000 light sensor to turn a white and black flashing monitor into binary data.

So far this is just a proof of concept that takes measurements from the light sensor which is held in front of a Macbook Retina display with different backlight levels. At 3/4 and full brightness it provides more than enough contrast to reliably differentiate between black and white when measuring the sensor with the Arduino’s ADC. What he hasn’t gotten into yet is the timing necessary to actually transfer data. The issue arises when you need to have multiple 1’s or 0’s in a row. We’ve tried this ourselves using an LDR with limited success. We know it’s possible to get it working since we’ve seen projects like this clock which can only be programmed with a flashing screen.

[Connor’s] choice of the TEMT6000 should prove to be a lot more sensitive than using just an LDR. We figure he could find a way to encode using multiple colors in order to speed up the data transfer.