Hi,
I need an effective light sensor which can recognize the interruption between the Tx and Rx. Basically something like a Ir sensor, But the Ir sensor which I am using rite now is not working due to the heavy lighting in the room. The distance between the Tx and the Rx is approximately 3-4 feet.
What am trying to do is, when ever people cross this tx,rx a message board "Merry Christmas" must pop up. Ive figured out everything else, except for the sensor. Could someone please help me with this.
And am really sorry if am missing the obvious!! I am just naive with sensors. I tried to google and couldnt find 1. Any help would be appreciated
IR remote controls avoid interference from ambient light by modulating the sender at about 40 KHz. The receiver has a 40 KHz bandpass filter that ignores signals that are not modulated at (or near) 40 KHz. You can use a 555 timer chip to add modulation to your sender and use a remote control receiver to detect it.