I am looking for an I/R sensor and LED for an upcoming PIC project. What do I look for on Digikey? I did a search but I get a ton of categories. I am not exactly sure where to look.

 

For the LED:
Optoelectronics > LEDs - <75mA, Discrete
Optoelectronics > Infrared Emitters

For the IR sensor:
Sensors > Optical - Photo Detectors - Photodiodes > choose 700nm+
Sensors > Optical - Photo Detectors - Phototransistors > choose 700nm+

<edit> Note that you can use IR LEDs as OK sensors. They are better than crude, but need to be lined up to within the LEDs optimal emission angle.

 

For the LED:
Optoelectronics > LEDs - <75mA, Discrete
Optoelectronics > Infrared Emitters

For the IR sensor:
Sensors > Optical - Photo Detectors - Photodiodes > choose 700nm+
Sensors > Optical - Photo Detectors - Phototransistors > choose 700nm+

<edit> Note that you can use IR LEDs as OK sensors. They are better than crude, but need to be lined up to within the LEDs optimal emission angle.

Thanks!


Can you suggest a better sensor?

 

What is the project?

Is it something an optical interruptor may be suited for?

A 38kHz modulated Tx/Rx?

Rangefinding?

Need more info to give any sort of useful answer other than generic solutions.

 

What is the project?

Is it something an optical interruptor may be suited for?

A 38kHz modulated Tx/Rx?

Rangefinding?

Need more info to give any sort of useful answer other than generic solutions.

A propeller clock. Basically I just need an RPM sensor. Sensor trips, clock starts, clock times out, lights go on.


But what I would really like to do is to communicate to the spinning board. That way I can set the time, change options without stopping the board. It would probably make debugging a little easier too. Though would require 2 PICs.

 

If you used a standard 38kHz Remote receiver package, mount it near the hub of the clock, and the signals can be sent to the same PIC.

Right Angle mount 38kHz receiver w/decoder. For transmitter, get a $9 universal remote and define your own codes.

 

If you used a standard 38kHz Remote receiver package, mount it near the hub of the clock, and the signals can be sent to the same PIC.

Right Angle mount 38kHz receiver w/decoder. For transmitter, get a $9 universal remote and define your own codes.

Aren't they I/R? Would that work with a spinning board? Where do I get the receiver end? Is that just a regular I/R sensor?

 

Aren't they I/R? Would that work with a spinning board? Where do I get the receiver end? Is that just a regular I/R sensor?

Yeah, that would be an IR receiver, but if you mount it close to the hub, it will spin in a very small circle, I wouldn't think polarity would be an issue unless you are using a laser IR emitter.

 

Yeah, that would be an IR receiver, but if you mount it close to the hub, it will spin in a very small circle, I wouldn't think polarity would be an issue unless you are using a laser IR emitter.

How hard is it to just roll my own transmitter? I was thinking if I could somehow suspend a transmitter over the spinning receiver then the non moving PIC could command the moving PIC. The moving PIC could simply process commands and light LEDs. All the timing of when to light the lights could actually take place in the non moving PIC.

 

Anywhere from easy and unreliable to very solid, depending on the amount of work to put into it.

You could implement the "standard" Sony or Sanyo protocols for noise immunity and code transmission in software, the transmitter would be buttons, a PIC, power source, and an IR LED.

The receiver would be the same thing, except an IR Receiver and outputs.

The only ones I've found at digikey are for fiber optic connections, so that doesn't include sunlight immunity.

I'm sure there are scraps of code around, for Tx, there isn't much to it, just blast the signal out and hope.

For Rx, it needs to find/latch to a carrier, then clock the data in. There is a lot of checking for background IR and timing on this end, in addition to decoding. That is why the ones with the built in decoders are nice, but not found in my quick search (Last I saw, around $5 each).