IR phototransistor array help!

[sam1r]

I am creating an array of 5x5 IR phototransistors of which an IR transmitter will be swinging across the array of phototransistors producing an output on the phototransistor recieving the IR signal (only one can be on at any one time). Whats the best way of wiring the array of phototransistors? I need a logic output from the 'on' phototransistor so I can use this information with a microcontroller. I have currently produced a simple IR sensing circuit with the use of a comparator. I could produce all sensors in this manner but this would require each output to be wired through an ADC which would then be sent to several microcontrollers.Is there a more efficient method??

 

[itsmoked]

If only one can receive the 'light' one phototransistor at a time, then you just hook them up as optical switches to a micro's ports and scan the ports. A/Ds need not apply.


With these systems it's always the ambient that nails you.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com

 

[IRstuff]

5 vertical wires 5 horizontal wires. Each detector connects 1 vertical to 1 horizontal.

However, your typical IR transmitter puts out a rather wide beam, so it's unlikely that you'll only have one on at a time, unless they are significantly separated.

TTFN

FAQ731-376

 

[sam1r]

itsmoked - is it possible to simply plug the output produced by the comparator in my circuit into a micro? I guess this is possible but the output voltage would need to be at a certain level right?

IRstuff - could you elaborate on how to connect the 5 vertical and 5 horizontal wires? Does this method incorporate my existing circuit?

 

[IRstuff]

Is this a school project?

TTFN

FAQ731-376

 

[MacGyverS2000]

We're getting a LOT of school projects the last several weeks :-(

Dan - Owner

http://www.Hi-TecDesigns.com