Hi, I'm trying to build a REM detector and I need some help.
The detector consists of an IR diode coupled with a phototransistor (OPB608A) and is placed on a closed eyelid. The idea is that as the eye moves behind the eyelid the amount of IR light reflected back to the phototransistor should vary.
In my current design I am connecting the emmiter side of the output of phototransistor to the adc of an 18x picaxe, and I am failling to clearly detect any eye movement.
My first question is which would be the best way to connect the phototransistor to the picaxe, as I believe I might be doing something wrong here.
This is how I have it connected now:
IR phototransistor
___
5v|-------c / \ e--------------┬---------|200R|-----|10k Pot|------gnd
¦
________¦__________
|adc pin of picaxe 18x |
----------------------
I've used a pot to try and find an optimal sensitivity but had no success.
How would it affect my signal if I connect the resistance and the picaxe to the collector side of the phototransistor?
The detector consists of an IR diode coupled with a phototransistor (OPB608A) and is placed on a closed eyelid. The idea is that as the eye moves behind the eyelid the amount of IR light reflected back to the phototransistor should vary.
In my current design I am connecting the emmiter side of the output of phototransistor to the adc of an 18x picaxe, and I am failling to clearly detect any eye movement.
My first question is which would be the best way to connect the phototransistor to the picaxe, as I believe I might be doing something wrong here.
This is how I have it connected now:
IR phototransistor
___
5v|-------c / \ e--------------┬---------|200R|-----|10k Pot|------gnd
¦
________¦__________
|adc pin of picaxe 18x |
----------------------
I've used a pot to try and find an optimal sensitivity but had no success.
How would it affect my signal if I connect the resistance and the picaxe to the collector side of the phototransistor?