| Author |
Message |
tarang
Joined: 27 Mar 2006
Posts: 30
|
 23 Jan 2008 4:15 ir trip sensor |
|
|
|
|
Hey folks,
Can anyone give me, explain me or direct me to how can i build an IR sensor from scratch. I want to use it for my maze solving robot project....
thanx.
|
|
| Back to top |
|
 |
davidgrm
Joined: 08 Apr 2006
Posts: 232
Helped: 21
|
12 Mar 2008 12:12 build ir sensor |
|
|
|
|
| You can use a photo transistor as a receiver and an LED. Modulate the LED at 40Khz and put a filter on photo transistor. (or you can buy a ready made receiver with filter like the kind used in TV for remote receiver)
|
|
| Back to top |
|
|
Google
AdSense
|
12 Mar 2008 12:12 Ads |
|
|
|
|
|
|
| Back to top |
|
|
tarang
Joined: 27 Mar 2006
Posts: 30
|
12 Mar 2008 15:15 building an ir trip sensor |
|
|
|
|
we are limited to the specific parts such as there is a pair of IR emitter + IR phototransistor. .....what if we pass the signal from the receiver to the band pass filter designed to filter out 40KHz reflected signal? then we need an amplifier to amplify the filtered signal right?
Added after 44 seconds:
we are limited to the specific parts such as there is a pair of IR emitter + IR phototransistor. .....what if we pass the signal from the receiver to the band pass filter designed to filter out 40KHz reflected signal? then we need an amplifier to amplify the filtered signal right? i think this might take lot of time in calibration.
|
|
| Back to top |
|
|
davidgrm
Joined: 08 Apr 2006
Posts: 232
Helped: 21
|
12 Mar 2008 22:24 filter ir mobot |
|
|
|
|
| you will most likely need to amplify the signal. You can use a small op amp for this. Also you need some kind of optical filter in front of the receiver. You can make this from a piece of green and red perspex sandwiched together
|
|
| Back to top |
|
|
kender
Joined: 19 Jun 2005
Posts: 1231
Helped: 88
Location: Stanford, SF Bay Peninsula, California, Earth, Solar System, Milky Way
|
12 Mar 2008 23:06 building ir sensors |
|
|
|
|
You're building a reflective proximity sensor, right?
Modulation and filtering is done to reduce the effects of ambient IR. If your robot is going to operate indoors, you don't necessarily need to modulate and filter, because the intensity of the ambient IR might be sufficiently low.
|
|
| Back to top |
|
|
