A circuit able to log up to twelve S0 pulses (or other pulses), based on the Microchip PIC18F26K22. Ethernet capable, real time clock and various outside connections.

This circuit is designed to capture the pulses from 12 different kWh-meters using the S0 pulses. The pulse circuit is decoupled by optocouplers. Pulses are captured by the MCP23017 GPIO extender.

Central controller is the PIC18F26K22. For LAN connectivity a breakoutboard is used with the Microchip ENC28J60. Pulses are logged with timestamp, there is room for two I2C EEPROMs for offline data storage.

All non-used pins from the PIC18F26K22 are available via a 20-pin header, including I2C and SPI buses, 5V and 3.3V.

There is also an external connector for the I2C-bus that is decoupled from the board.

This project is currently in design phase, I would like to hear your feedback on the schema.