How to connect LED detector 2 Pins?..program microcontroller

[Terrano]

Hi,

I'm using an infrared LED detector with 2 pins. My question is, how do u connect the second pin?..do u connect a resistor and then to ground and check the voltage on the oscilloscope...i.e. the second pin is giving the output as current or voltage?

Also I'm looking for a good site that can teach me how to program a microcontroller to give an FSK output signal and be able to reduce the duty cycle.

Thanks

 

[Nigel Goodwin]

Your question is far too vague, what's an 'IR detector'?, there's no such component - do you perhaps mean a photodiode?.

I suggest you try posting what you are trying to do!.

For IR remote control help, try my PIC tutorials - using an IR receiver IC makes the receiver side simple.

 

[Terrano]

Sorry, I meant an infrared LED receiver or photodiode

I'm just trying to establish a wireless infrared channel for data transmission.

So I’m using a transistor as an LED driver to turn on an off the infrared LED emitter, I know the LED emitter is flashing (I just know) but I don’t think the infrared photodiode (2 pins) is receiving anything, I connected one pin (longest of the 2 pins) to a 5V and the other pin to a transimpedence amplifier (convert current to voltage and amplify it), is this correct? Should there be any other circuit between the transimpedence amplifier and the photodiode?

And yes the infrared emitter and photodiode have the same wavelength 860nm.

Also I have looked at a few LED drivers on the net and some LED driver circuitry is so big y do we they need such big LED drivers just to deliver a constant current through the LED emitter?...Isn't a BJT or MOSFET and maybe some resisters enough to drive an LED?

Where can I find an easy tutorial that can teach how to choose and program a microcontroller to give an FSK output and be able to reduce duty cycle if desired.

Thanks

 

[Nigel Goodwin]

Sorry, I meant an infrared LED receiver or photodiode

Again, you're confusing yourself - it's JUST a photodiode, NOT an IR receiver. Building an IR receiver around a photodiode is quite a difficult project, and prone to instablity (due to the massive gains required). Far, far easier to use a simple three pin receiver that does it all for you! - including detecting and removing the 38KHz carrier signal used.

Where can I find an easy tutorial that can teach how to choose and program a microcontroller to give an FSK output and be able to reduce duty cycle if desired.

As I mentioned before, my PIC tutorials show how to do IR remote control (based on the Sony SIRC's system).