EZ-430 Chronos Wireless Watch controlled Door Entry System.

I have been waiting for cool projects using the TI EZ-430 wireless watch, and it comes up one today! You can unlock the door wirelessly by just taping the watch screen with a sequence. The sequence is then detected by the internal accelerometer and translated to a door lock pattern. If it is correct, it would unlock the door:)

Hard to say how cool is it, Lets see the demo! Cool Project, Ziyan!



Details of implementation: https://ziyan.info/2010/01/secure-wireless-door-lock/

Gyroscopes VS Accelerometers.

Accelerometer is now very famous because it exits in most of the smartphones like iPhone, Android and Palm Pre. Recently, I got a RC mini-helicopter with built-in gyroscope to detect the rotational movement, it makes me interested in the differences between the two sensors. After some Googling, I found a good video tutorial that compare the two sensors. The InvenSense, whom made the Wii MotionPlus, using Gyroscopes and Accelerometers to capture precise human hand movement. The comparison video goes here:


My cheap RC mini-helicopter:

The single-axis gyroscope inside the helicopter:


It is used to detect if the helicopter rotates left or right unintentionally while the main blade is rotating. The MCU inside the helicopter would try to control another motor to rotate another blade to counter the rotation if necessary based on the gyroscope reading.

Here is my video showing the balancing control of the helicopter:


Furthermore, there are some articles worth to read:

• accelerometer and gyro, difference


• Gyrobot - a balancing robotic platform


• FAQ: What's the difference between a gyro and an accelerometer? Do I need both?


• InvenSense