Abstract: A high efficiency LED lighting system with four LED modules. Each module has heat sink assemblies arranged in rows. The heat sink assemblies comprise an LED package mounted on a heat sink reflector. The LED package has a flat find diffusing lens positioned over the diode. A diffusing lens is spaced apart from the heat sink assemblies. A switch mode power supply controller provides power to a pair of light sources. The controller includes a low voltage programmable current source and adjusting elements for independently adjusting the current to the LED light sources. The controller also includes a first communication port for receiving a communication from an external device and a second communication port for sending a communication to a third power supply controller. These ports provide an upstream and downstream communication capability through a chain of controllers so that input from a device can be communicated upstream and downstream.