Power Level Monitor Built Around LPC2138

The purpose of building this LPC2138 based power level monitor is to determine the biggest usage of electricity in the households.

The LPC2138 ARM7 microcontroller was chosen for this project to provide help on keeping track of the power usage in order to anticipate the monthly electricity bills charges. The system uses a current transducer for measuring the power levels where it senses the current flow and a step-down voltage transformer to sense the voltage. The power RMS is calculated correctly as the device detects zero crossings of voltage and current in order to determine the phase shifts. The reason for choosing a current transducer is to isolate the microcontroller circuits from the electrical circuits. the microcontroller initializes its internal peripherals and jumps to an endless loop during operation where average power is continuously computed.

The 7-segment LED indicator mounted directly on the device is used to view the power level information. Another way of viewing is by sending the information through USART to monitor on computer screen to obtain statistics. The 4-digit LED display shows the average power that is computed in terms of RMS voltage, RMS current, and power factor.

Rest of the project