DALI Bridge FPGA-Based Implementation in a Wireless Sensor Node for IoT Street Lighting Applications

Abstract

Smart lighting systems based on the Digital Addressable Lighting Interface (DALI) protocol are the most suitable for street lighting systems, allowing digital lighting control operations. Unfortunately, the microcontrollers, which are commonly used in the Wireless Sensor Network nodes to control the lamps, do not implement this protocol. The DALI protocol implemented by software in the microcontroller consumes hardware resources (timers), processing time and requires a precise temporal analysis of the application, due to the strict bit times and the Manchester coding that it uses. In this work, the design of a bridge is proposed to free the microcontroller from the implementation of the DALI protocol. The novelty of this work is the implementation of the DALI Bridge in a low-cost Field-Programmable Gate Array (FPGA) with low power consumption. The bridge has been described in the hardware description language following the 1076-93 and 1076.3-97 standards, to guarantee its portability. The results of the synthesis show that a minimum amount of logical and routing resources is used, that the power consumption is in the order of tens of mW, that it has a very small latency time and that it supports a high operating frequency, which allows adding new functions. Its operation is verified by implementing a wireless sensor node using an FPGA of the Lattice Semiconductor iCE40 family.