modulators, ir transmitters, ir detectors, remotes, switches, etc.. http://www.reconnsworld.com/forum/list.php?3 Wed, 08 Sep 2010 23:30:00 -0700 Phorum 5.2.9a http://www.reconnsworld.com/forum/read.php?3,377,377#msg-377 http://www.reconnsworld.com/forum/read.php?3,377,377#msg-377
I have been looking all over the net for a very simple IR circuit that uses 5mm led package types that will fit in my bot head design. The accuracy does not need to be perfect. I just need something that will keep my bot from walking in to walls and other large objects. I was wondering if the circuit posted in this thread and using radishack's match IR emitter/transistor will work with the basic stamp 2.

Here is a picture of my design.


]]> Botwire Infrared Tue, 13 Dec 2005 12:22:23 -0800 http://www.reconnsworld.com/forum/read.php?3,361,361#msg-361 http://www.reconnsworld.com/forum/read.php?3,361,361#msg-361
1) I have used a simple circuit similiar to Andrew's attached here. I connected a 5v supply to an IR emitter in series with 220 ohm resistor for the emitter side.
For the IR detector I have connected the collector side to a 5V supply in series with a 470 ohm resistor. The emitter side of the IR detector is grounded. I have connected basic stamp I/O pin between the 470 ohm resistor and the collector of the IR detector. When the I/O pin is low meaning the IR detector is turned a tested alarm system connected to the basic stamp should not go off. Once an object comes between the emitter and detector the I/O pin should go high and set off an alarm.
The problem I have is the detector never gets turned on when the emitter side is turned on. I measure the voltage across the emitter to 1.3V which is the turn on voltage of the LED. The voltage across the collector and emitter of the IR detector is always at 5V meaning that the detector never gets turned on.

2) The second method I have tried (but in vain) is using 555 timer to produce a modulated square wave signal at about 30 Khz. The output of the timer goes to the emitter. One problem I have seen is once I connect the IR emitter to the output of the timer the output voltage seen with the Oscope goes down to 1V and it gets a little distorted. I finally got a good signal out but does not seem to turn on the IR detector.

Any where I searched seem to indicate that the first method should work at least in doors with less ambient light.

I appreciate any help.
Deq]]> guest Infrared Sun, 20 Nov 2005 17:43:27 -0800 http://www.reconnsworld.com/forum/read.php?3,28,28#msg-28 http://www.reconnsworld.com/forum/read.php?3,28,28#msg-28

parts:
R1 270 ohm resistor
L1 Visible LED
S1 On/Off Switch
IR Module Sharp GP1U5X IR Detect Module (or compatible)


Use this circuit to test if the light coming from your 40khz IR emitter is really emitting the right frequency. The schematic says to use a GP1U5X ir module, but probably any 40khz detector module will work.. I used a GP1U26X module.]]> andrew Infrared Mon, 28 Nov 2005 18:00:39 -0800 http://www.reconnsworld.com/forum/read.php?3,27,27#msg-27 http://www.reconnsworld.com/forum/read.php?3,27,27#msg-27

parts:
U1 555 Timer IC
R1 47 ohm resistor
R2 470 ohm resistor
R3 5k variable resistor
C1 0.0047uf ceramic capacitor
LED1,LED2 Infrared LED's


This circuit oscillates two infrared LED's at 40 khz. To make sure it is transmitting IR light, you can get a little tool from radio shack for about $5. It is a small sheet of plastic about 1" by 3" with a special strip of material, that when exposed to IR light glows (it's actually kinda cool..) A way to check for 40khz IR light is to build a circuit that lights an led when 40khz light is detected. You can get the schematic by clicking here.]]> andrew Infrared Wed, 26 Aug 2009 20:37:18 -0700 http://www.reconnsworld.com/forum/read.php?3,26,26#msg-26 http://www.reconnsworld.com/forum/read.php?3,26,26#msg-26

parts:
R1 270 ohm resistor
R2 10k resistor
LED1 Infrared LED
Q1 Infrared-sensitive photoresistor


This is a very basic infrared detector/emitter circuit. One major downside of this circuit, is that ambient infrared light will interfere with its detecting obstacles.]]> andrew Infrared Wed, 18 Jul 2007 09:48:09 -0700