Design and Evaluation of Low-Cost Load Monitoring and Control Modular Board using MQTT Protocol

Abstract

 This paper proposes a modular and economical design and development of a circuit that could measure monitor and control electrical power consumption for homes, offices, or industrial plants. The proposed circuit was designed and developed using the Node MCU ESP8266 and Tasmota firmware with the MQTT protocol. The hardware circuit consisted of two circuits: the main circuit with a processor and a port for communication; and the expander circuit with 16 channels applicable for both digital and analog inputs. Power and power quality measurement utilized a digital AC power measurement module PZEM004TV3 and a ACS712 current sensor. The data was sent to display through the platform Home Assistant program with the MQTT broker installed on the Raspberry Pi board. The analysis and tests of the developed circuit showed that the circuit could measure and control the power consumption as designed, having the ability to operate in a modular manner. The investment cost was 412.5–931 Baht (11.3 – 25.4 USD), 2–5 times less expensive than the existing circuits in the marketplace, and the capability of long-distance data transmission. The accuracy and completion of the transferred data was more than 98.36% with a low average power consumption of 8.5 watts and achieved 1.64% higher power quality estimation accuracy than the standard equipment. The advantages are easy to connect to various platforms, economical price, can add measurement circuit. Note that a server is required for the MQTT protocol.