[Greg Lipscomb] from DIY Live gave us the heads up on his latest project: Macro photography with a disposable camera. While playing around with the Kodak Max outdoor camera he discovered that the lens was behaving similar to a jewellers loupe that he had. He figured that it could probably take macro shots with some tweaking. He disassembled the camera and then drilled a larger aperture since F11 would have been too small. Then he attached the assembly to the lens from his Canon 10D and fired away. He’s got example pictures on his site; they’re pretty good for something held together by scotch tape.

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Canon’s first consumer printer capable of printing directly on CDs was released in 2003. Unfortunately for anyone in the US, this feature wasn’t included. Canon just put a plate over the CD tray slot. A community has sprung up to assist people in activating this feature. You need to remove the cover first. Then you can install the CD tray which you either purchased or constructed following their plans. The final step is to set a registry key so that the CD printing menu appears.

[via Digg]

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Spark Fun Electronics has made a name for themselves recently by selling interesting parts like this $20 color LCD. Hack-A-Day reader [Refik Hadzialic] decided to buy one and see how easy it was to use. It is a 128×128 display and should be a clone of the one you would fine in a Nokia 6100. He wired it up to an ATMega32L-PI8 microcontroller. He grabbed source code from a couple different places and eventually got something to work. In the end, the actual control commands seem pretty simple. Refik has been posting a lot of quick projects and info on his site, e-dsp. Have a look.

Continue reading “Controlling A Cheap Color LCD” →

Risto K?’s PC to R/C interface let’s you connect to your Futaba radio transmitter. You can use this device to do direct control of your R/C project: prewritten trajectories, user called macros, or direct PC joystick control. He’s built two versions. The original one used multiple D-latches. The second version was an attempt to reduce the number of components. It uses interrupts in the microcontroller software instead of the latches. This would normally cause a lot of jitter, but Risto implemented the interrupts in assembly. The controller can handle up to 16 channels. The LCD displays the last pulse-width and channel.

[thanks Will]

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Reader [alberto ricci bitti]’s DVD thermometer is a temperature sensing infrared remote that controls a DVD showing the temperature. Since the box doesn’t get any feedback from the DVD player, it stops and starts the disc to make sure it is at a known state. The brain of the device is a Motorola MC68HC908QT4, an 8-pin microcontroller. Communication with the Maxim DS1621 temperature sensor I2C bus is done in software. Even if you don’t want to build a gaudy thermometer the article features a lot of interesting information. It covers reverse engineering the remote, emulating an I2C bus, and creating a programmable pulse generator instead of bitbanging.

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LEDs are extremely common in electronic devices. They are used as light emitters, but can also be used as light detectors since they are photodiodes. By quickly switching between light emitting and detecting, you can use the LEDs to determine the ambient lighting and even do bidirectional communication. MERL has a good paper covering the basics of how this system works and how they used it as a “last-centimeter” communication device. The system can be implemented using one LED, a resistor, and two I/O pins. So, it could be used cheaply in almost any device. The microprocessor quickly switches the LED between emitting light, detecting light (LED acts as a charging capacitor), and measuring the discharge rate of the LED to determine light level. Jeff Han has a neat video demo of how this system can be used as a proximity sensor.

UPDATE: [hawkeyeaz1] pointed to a blog covering one person’s investigations into LED sensors.

[thanks branen]

So, if you were wondering what [Kenn Sebesta] was working on that needed yesterday’s hack, this is it. The plate can maintain the cue ball in its current position or make it travel an arbitrary path like a circle or figure-eight. It can also avoid obstacles placed on the plate. Kenn has documented his project thoroughly and covers many of the problems he faced along the way, like how to find the ball in the webcam image. Like most quality thesis projects, it’s constructed out of LEGO.

UPDATE: Now with video!

Continue reading “Ball And Plate Doohickey” →