I am trying to build a little tracking device system having two light sensors mounted on it that tracks and points to a LED that can be placed at different positions in the room. The two sensors would be mounted on a servo motor that can rotate. The servo is placed in a fixed location in the room. As we move the LED around the room the servo rotates towards the LED until it is in straight line of sight.
This is my idea: the two light sensors receive different amount of light from the LED if the servo is not facing the LED directly. I think I need a difference amplifier that will measure the voltage difference between the two sensors and control the servo so that it rotate until the difference seen by the two sensors is zero or close to it. At that moment the two light detectors will be facing the LED.....
How do tell the servo to rotate to that angular position where the comparator output is zero? Do i need some feedback loop between the servo and difference amplifier? How does the servo know to rotate either left or right to reduce the voltage difference at the difference amplifier?
Can I use Arduino Uno and the servo library, write some small code and be ok with it, without the need of difference amplifier?
I think I also need a a blinking LED in a room that has other lighting, like a LED flashing at 38 KHz and infrared receivers. Infrared sensors give an output that is LOW when it receives a signal. If no inputs are low turn left (or right, whatever) to rotate until you find a signal. If one is low turn towards the other one. If both inputs are low, stop turning.
Any suggestion on how to solve this problem the simplest way?