This project allows you to store and use your own gesture to unlock a security lock. This can be especially useful for people with physical disabilities particularly in their fingers. The attractive feature of the project is that the user makes the pattern in the air and not on any surface. The pattern can be change any number of times and also saves you from the hassle of carrying a key to unlock locks. The gestures are captured by using four infrared sensors placed in the box within the range from 10 to 80 cm.
The analog output obtained from the infrared sensors is fed to the internal ADC of the microcontroller, in this case its Atmega 128p, which maps the corresponding analog readings to the equivalent digital output. Apart from matching the required pattern, the system also checks that the pattern is also made at the require position with some margin of error pre-set. At present point of time, the gestures that are recognizable are only 2-D gestures, but with use of additional sensors to measure depth the pattern accuracy can be increased.