Closed loop light controlling with MSP430

Svend Clausen said:

I got a lot PID controls mostly for heating system. I don't think that they are useful for lighting control

Why not? Well, the response time of a lighting system is way shorter than that of a heating system, btu that makes things easier
While in a heating system you have to 'overdrive' the heater, so you'll raise temperature fast, but then need to reduce it early enough so you don't overshoot, a lighting control acts more responsive: the moment you raise the output, the lighting increases, so you can simplify the regulation: you can mostly ignore the I component of the PID and the D component mostly too. Ideally, you only need the P (proportional).
If the sensor reports 50% of desired light, you have to double the output to get 100%. Of course, even at 0% output it won't be 100% dark, and the relation between output power and light isn't linear (nor is the light sensor, usually), so you'll need a bit more.

Th equesiton is: how do you control the light and what type of light. Do you use a phase dimmer on a light bulb, or a PWM control on an LED? The algorithms are different, and so is the interpretation of the light sensor data (which will likely be pulsed on a PWM system)

Hi, thank you for the answer.

I am using a 1-10V sink output controlled by a PWM signal.