Hey everyone I am working on a project of mine to help further my cancer research. I am trying to create a system where the lack of light against and LDR will turn on a motor to the speed set by a controller. Pretty much I want the LDR to give power to the controller which then will determine the speed of the motor. I am not really sure how to go about this or if it is even possible so any help is greatly appreciated.
Certainly possible and not really difficult. An Arduino Uno would be a great controller along with a proper motor driver. We need to know the specifications of the motor. The salient specs are rated voltage and stall current to be able to pick a motor driver. The Uno can, using an analog input, measure the light intensity. Then set an output PWM signal to the motor driver to control the speed. If the speed must remain constant under varying loads the motor can supply feedback to the Uno via an attached encoder and the Uno can adjust PWM to keep the speed constant.