Hi All,
I am attempting to measure distances of objects with a Sharp IR Proximity Sensor (such as the GP2Y0A02YK0F). I would like this sensor to work in an environment that is somewhat `noisy` in the way of IR light (multiple sources of IR light that cannot be controlled). Is it possible to modulate the signal of the Sharp IR sensor to filter out background noise?
Thanks!
There are many ways to
There are many ways to modulate a regular IR emitter/detector arrangement, however the Sharp IR modules have their own built-in controllers which render this impossible, or at least close enough to it. On the other hand they’re well designed with ambient interference in mind, so you may find your sensor works better than expected anyway.
I suggest you test your sensor out in the environment you need it to perform in, and see if the results are satisfactory. If a particular situation is causing the sensor problems there may be something that can be done about it.
What Platform
What pltatform are you using as if you have a usb compatable board you can get sensor readings to get a numeric data set when you test your sensors. it will give results that can be put into a graph and easily compared. if not you should be able to rig up a servo with dial thing to show the best reading.
Thanks
Sorry for the late reply here. Thanks for all the suggestions guys. I am actually curious if anyone happens to know if the Sharp sensors already modulate the IR LED in them? I can’t seem to find this in the data sheet but see an “oscillator circuit” in their very general block diagram. Perhaps I shall set up a simple IR detector to an oscilloscope and see if I can pick up a signal from the Sharp range finder.
As for testing the sensor in the environments I had in mind, I think I will do just this. I am a bit curious, how would I go about creating intentional noise to interfere with the sensor? Could I simply shine an IR LED flashlight type device on the sensor to skew the readings?
Go outside =)The Sun is a
Go outside =)
The Sun is a huge source of DC IR interference. As for modulated IR interference, indoor lighting pulses at mains frequency (50/60Hz) so try using the sensor near different types of house light. The 3rd most likely source of IR interference that comes to mind is TV and other similar IR remotes which are usually modulated at 38-40kHz, so point some of these at your sensor and press some buttons, see what happens.
Going back to the Sharp’s internal oscillator, the IR detector + oscilloscope idea is a good one. Just make sure you’re using a regular IR phototransistor/photodiode, and not a detector that’s only tuned in to a particular frequency band, otherwise you might not see anything.
