LCD1602实现四路温度控制系统，用三个按键分别对四个温度的上、下限的设定，假如温度大于预设d温度的话则继电器动作！有原理图和相应资料-LCD1602 realize four ways of temperature control system with three buttons, respectively, in four temperature limit set, if the temperature, temperature than preset d relay action! Schematic diagram and the corresponding data there