Tutorial with Schematic/Diagram and Materials List on how to make an IR Sensor?

[MaltiK]

I looked in the IR tutorial, the diagram just didnt do it and there were no materials list, can someone post a link or anything?

[pomprocker]

Have you considered purchasing one already made, like the Sharp IR?

[MaltiK]

I want everything in this robot to be from scratch, meaning I want to buy everything and assemble it together, aside from them motors, its a good learning opportunity.

[hudbrog]

There are different kind of IR-sensors... Do you want IR range sensor, or just IR bumper kind of sensor, which would only tell you if there is an obstacle or not on predifined distance.
First one is Sharp GP2Dxx line of sensors.
Second you can do from scratch and if you want I can show you how(not tutorial, but an explanation with schematics)

[MaltiK]

There are different kind of IR-sensors... Do you want IR range sensor, or just IR bumper kind of sensor, which would only tell you if there is an obstacle or not on predifined distance.
First one is Sharp GP2Dxx line of sensors.
Second you can do from scratch and if you want I can show you how(not tutorial, but an explanation with schematics)

I would like that very much

I'm trying to make an obstacle detector, I have made two before, one only sensed objects a couple CM ahead (fail), and the next I just used for a wheel encoder...

[hudbrog]

Ok. So, obstacle detector. On first glance it is pretty easy to create - you have LED and photodiode, by measuring photodiode current you can determine brightness of light ahead of it. The only problem is, in real life is doesn't work that well. Actually, it just doesn't work. Lots of lights everywhere which create interferences and stuff like that. To avoid that we need some way to determine that we are receiving light which we are emitting and not just some kind of light. Basically, easiest way for that is to use pulsed signal for lighting. I.e. you measure light level with your LED turned on and off, and if those level are equal - its just an interference. But than, you need some kind of filters, amplifiers and stuff like that. To messy. At that moment we are starting that there are things that use pulsed IR light... remote controls for TV as example. And for that they use pretty specific part.
As example - TSOP17xx by Vishay Semiconductors. Two last digits tell you carrier frequency. Basically, it has high output when there is no signal, or low output when it senses signal on predefined frequency. (see figure 7 in datasheet). And best thing is that it is really protected from interferences of any kind.
So, all you need is mcu(any will work actually). Schematics could be found here (http://roboforum.ru/mediawiki/images/8/80/Ir_locator30.gif). These were created by Russian RoboClub long time ago... but they work just perfectly.

[Admin]

Just to help you understand the magic . . .

When I make a circuit and I need a sensor (or any component), I search mouser/digikey sorting through hundreds of components and reading dozens of datasheets. If after doing all this and I'm still not sure, I ask others what they think about what I found.

This is what the experts do, so its a skill you need to learn if you want to always make circuits 'from scratch'