Abstract: This paper designs and fabricates a hardware circuit for a digital energy meter system based on a combined sensor. The MSP430 series microcontroller from TI Corporation is used to implement functions such as current and voltage signal acquisition and processing, parameter calculation, and communication. While introducing the circuit, some practical methods for improving system reliability and electromagnetic compatibility are also explained. The designed system achieves good measurement accuracy. Keywords: Energy meter; Sensor; Microcontroller 1 Introduction The energy meter is a multi-channel data acquisition and processing microcomputer system with a computational power multiplier as its core. The system uses developed current and voltage sensors to collect instantaneous values ​​of input AC current and voltage. These values ​​are then converted into standardized voltages that can be sampled by an ADC through filtering, integration, and amplification circuits. A 12-bit A/D converter then quantizes these voltages into 12-bit digital quantities (binary two's complement). These two simultaneously quantized digital quantities are multiplied and accumulated by a multiplier-accumulator. The accumulated output signal for one sampling cycle is then sent to the CPU of an MSP430 microcontroller for calculation and processing, yielding electrical parameters such as energy, active power, reactive power, and power factor. The system includes an interface for an LCD display module to show the required electrical parameters. It also provides communication with a host computer, allowing remote control of the energy meter by the host computer to read current electrical parameters. The data acquisition system has both analog and digital outputs, providing the necessary signals for metering and protection devices simultaneously. For more details, please click: Design of a Digital Energy Meter System Based on Combined Sensors.