关于温度控制系统的位置型PID控制算法，设定温度比当前温度低时，PWM的占空比100，全是高电平，停止加热；设定温度比当前温度高很多时，PWM的占空比100，全是低电平，全速加热。-Temperature control system on the location-based PID control algorithm, set the temperature lower than the current temperature, PWM duty cycle of 100, is high,