A Remote for CHDK Cameras Made Possible with Arduino

[AlxDroidDev] built himself a nice remote control box for CHDK-enabled cameras. If you haven’t heard of CHDK, it’s a pretty cool software modification for some Canon cameras. CHDK adds many new features to inexpensive cameras. In this case, [AlxDroidDev] is using a feature that allows the camera shutter to be activated via USB. CHDK can be run from the SD card, so no permanent modifications need to be made to the camera.

[AlxDroidDev’s] device runs off of an ATMega328p with Arduino. It operates from a 9V battery. The circuit contains an infrared receiver and also a Bluetooth module. This allows [AlxDroidDev] to control his camera using either method. The device interfaces to the camera using a standard USB connector and cable. It contains three LEDs, red, green, and blue. Each one indicates the status of a different function.

The Arduino uses Ken Shirrif’s IR Remote library to handle the infrared remote control functions. SoftwareSerial is used to connect to the Bluetooth module. The Arduino code has built-in functionality for both Canon and Nikon infrared remote controls. To control the camera via Bluetooth, [AlxDroidDev] built a custom Android application. The app can not only control the camera’s shutter, but it can also control the level of zoom.

Gesture control uses WiFi doppler shift


We’ve said it before: in the future simple interfaces will use nothing but your body. At least at first glance that’s the case with this WiFi-based gesture control system. If you have Internet at home you probably have a WiFi access point. That’s the first portion of the equation. The remainder is a way of measuring how the radio waves bounce off of your body. So far this is being done with Software-Define Radio (SDR) but researchers at University of Washington think it may be possible to build the technique into future WiFi devices.

The demo video shows this man waving his arm to adjust the volume of his home entertainment system. Intuition tells us that this would be impossible if your arm wasn’t the only thing in motion at the time. But that issue is quickly addressed. Multiple antennas can track multiple people at the same time. There is also consideration for false-positives. The system requires a moderately complex wake-up gesture sequence to prevent you from, say, accidentally turning on the stereo when you roll over in bed.

If you’re having trouble wraping your mind around this, consider this ultrasonic music player. The WiFi version does the same thing, but processing changes in the returning radio waves is much more complex.

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Hacking iPod headphone controller for use with Android

[Buddhra] wanted to use a set of ear buds that also had a controller built into the wire. The headset he chose to go with is meant for use with iPod, but he figured it should be possible to make it work with Android too. He was right, and managed to alter the controller for Android use and still fit it into the original case.

He had already made a custom control module that has fast forward and rewind features and play/pause events. The signals used for the controls are based on resistive dividers. The play/pause button on the iLuv headset already worked, so he cracked the controller open to see why the forward and back buttons didn’t work. It turns out all he needed to do was add the right resistors to those buttons. Here you can almost see the 0603 surface mount packages he used to add a 220 Ohm resistor to the back button, and a 600 Ohm resistor to the forward switch.

Very clean Android headphone controller project

Here’s an Android headphone add-on so clean that most people won’t know you built it yourself. [Will Robertson] was unsatisfied with the stock headphones that came with his HTC phone, but didn’t want to lose the control interface when upgrading. He built this add-on that lets him control the Android music player.

He was inspired to do this after reading about the control interface in one of our previous features. That hack detailed how to add control based on the 4-conductor headphone jack, but didn’t see us through to a clean finished product. [Will] picked up where it left off by designing a sleek surface mount board that hosts a headphone jack and three tactile switches. A patch cable is soldered opposite the jack, making this work as a pass-through device. The icing on the cake is the shrink tubing that masks the fact that this is a diy dongle.

If you want to follow his lead, [Will] posted his EagleCAD design files and footprints for the components he used in the post linked at the top.

Bluescripts makes Bluetooth control from Android a bit easier

Here’s a way to gain control of your projects using an Android device. Bluescripts is a free app available in the Android market that makes it a bit easier to make interfaces to send customizable messages. If you have a Bluetooth receiver in your project, connecting to it is as easy as putting the MAC address into an XML file on the Android device. Each tag in that file has a name, as well as the address of the target and the message that should be sent. On the receiving end, you just need to make sure your project hardware is ready to receive an ASCII message and act based on what comes through.

Check out the demonstration video after the break. Perhaps it’s not as cool as you could do if you were writing your own Android program, but we can’t think of anything we’ve seen that makes an Android interface this quick and easy.

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Patching into Android music control

Here’s a look at the TRRS cable that Android phones use. [Rich Kappmeier] want to control the music player on his Nexus One while driving. It’s not necessarily a safe endeavor if you’re staring at the screen and poking away with one hand while trying to stay in your lane. A little bit of research helped him figure out how the hardware in a headphone controller worked and he decided to incorporate that into a connector cable for the car.

The control signals rely on a specific resistance between the TRRS function ring and ground. Once he worked out the chart above and targeted the correct resistance values he built a rocker switch for Fast Forward and Reverse, as well as a Play/Pause button into the connector cable. You should be able to use this for more than just music control. Take a look at our Android Development tutorial and see what else you can come up with.

[Thanks Alastair]

R/C PPM hacked

[Thomas Pfeifer] has taken the PPM signal produced by model aircraft wireless controllers, and with an ATMega8, converted the signal to act as a USB joystick. Which means you can now use a standard R/C remote control to fly model aircrafts on your computer. Of course now with PPM decoded you could also use the signal to control any electronic device. Like your mower, iPod, and we’ve even seen remote controlled pellet guns. Catch a video of [Thomas] flying a simulated quadrotor helicopter after the jump.

[Thanks Max]

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