I'd like to hear your ideas for increasing the range of proximity detection sensor that uses an IR LED & the Parallax IR detector.
I am using a Radio Shack high-output IR LED, a Parallax 40kHz IR detector [noparse][[/noparse]350-00014], and a BS2P24 micro. The LED is mounted directly above the detector so that it shines in the same "line" as the detector. When an object comes near, it reflects the IR from the LED back to the detector.
According to its datasheet, the IR LED 276-0143
operates at 940nm wavelength and outputs 16mW @ 100mA.
The IR LED is connected, in series with a 470 ohm resistor, to an output pin in the BS2p. It is controlled using the FREQOUT command [noparse][[/noparse]FREQOUT, pin, 1, 37500].
The IR detector is connected to an input pin on the BS2p and is read using the IN command.
This system can detect an object at a range of about 6 inches from the LED/detector, but beyond that it doesn't "see" anything.
I'd really like to increase this detection range to about 9 or 12 inches.
Do you have any ideas or suggestions for how I could do this ?