By the way, we’ve covered a PID library for Arduino before. While this post talks about temperature, PID control is used for everything from flight control to levitation.

Practical PID – Arduino Experiment To demo PID theory in action, I picked up an Arduino Uno from my messy drawer along with a GL5528 photoresistor (LDR) and a super bright 5mm blue LED.

A sensor measures flow for the Arduino, which adjusts a control valve actuator to maintain the specified setpoint. The software uses proportional and integral control (the PI part of a PID loop).

Lepeng Song, Liangxian Wen, Yongkang Chen, Yang Lan, Junlin Zhang, Jianqu Zhu, Variable-rate Fertilizer Based on a Fuzzy PID Control Algorithm in Coastal Agricultural Area, Journal of Coastal Research ...