body detector

[george leung]

I have a project to build once my hand approaches the sensor(or metal plate) appro. 10 cm, A LED lights on; at about 8 cm distance,
B LED turns on and at about 5 cm, C LED turns on(Total there is 3 LED).Would somebody give me any circuit diagrams??( As I use a MCU to check any frequency change if there is any movement so that which LED to turn on).