The purpose of portable Power Meter project is to measure and average the voltage and current from each leg of the generator, and display the information on a 16×4 LCD screen. The project use Atmel ATtiny26 as signal processing and control. While the firmware is developed using Bascom-AVR.
The high voltage sensors for voltage and current are isolated from the signal processing circuit by a quad opto-isolators. The signals, supplied to the signal processing section, are analog and proportional to the voltage and currents feeding the load. The signals from the opto-isolators are feed to an AC coupled full wave rectifier and filter. AC coupling is used to remove offset effects. It is assumed that because of the sine wave nature of the generator output, and the characteristics of typical household loads there are no DC current or voltage components of interest.
The signal from the full wave rectifier and filter is applied to the ADC inputs of the Atmel ATtiny26. The microcontroller is used to measure the signal, apply simple filtering, and present the voltage and current draw information to the user by way of a 16×4 LCD. The generator power meter project is designed by Brian Corrie.
Project Detail and Documentation