i need simple laser light source and detector circuit
I have a couple optical joysticks that Ill be porting over using a teensy2.The comments here are on track. The joystick has 2 lights on the bottom of it.
and 2 photodetectors, one is directly below the lights, and the other is at a 75 degree offset, and slight offset from center. I think the lights are the same colour, and they are in series. moving the joystick in any particular direction will cause a variation in intensity. center is brightest on e1 and 50% luminous on e2. hard right is e1, dark, e2 dark, hard left is e1 dark, e2 bight. full forward, and full back, are varying intensities, on e1,e2. The teensy2 has 10 bit analog. I should be able to make 1024 unique comparisons pretty easily. The 2nd eye being offset from center was a good observation for my use. it means the circular motions of the joystick produce an elliptical illumination pattern.
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LED attached to the bottom of the joy stick. 4 photodetectors, arranged in a square underneath. Illuminate the LED dimly. Take the orthogonal pairs into a differential amplifier, take that into labview.
thank you sir for u r kind reply , it wil be nice if u give tutorial links for this :)
It's your college assignment I am not prepared to do your work for you, beyond laying down the delete you need.
Forget lasers. All you need is a bright light and a detector
sir i just want to make an optical joystick with atleast 8 direction movement . i need a sensing principle for the direction movement and i need the result in labview
So just on/off, not proportional, and for a college project ?
yes sir for college project . if i move forward, left, right and backward how it detects movement and move accordingly. i want the sensing principle like intensity based or reflective based .. give me some suggestion
not like simple on/off switch
I assume you want this to be proportional in that the signal is proportional to the movement.You have really 2 choices 1. Butcher an optical mouse and arrange for the joystick movement to shift the mouse sensor across a pad.2. Build a simple device to vary the amount of light coming from an LED sense with a photo transistor or LDR (light Dependent Resistor) and process the results with a microprocessor.