This is a design in development for a 12-input puse counter for interfacing with 12 utility meters.
Many meters have pulse outputs, including electricity meters: single phase, 3-phase, import, export.. Gas meters, Water flow meters etc
The pulse output may be a flashing LED or a switching relay (usually solid state) or both.
In the case of an electricity meter a pulse output corresponds to a certain amount of energy passing through the meter (Kwhr/Wh). For single-phase domestic electricity meters (eg. Elster A100c) each pulse usually corresponds to 1 Wh (1000 pulses per kwh). For the case of higher power meters (often three-phase) each pulse corresponds to a greater amount of energy eg. 2whr per pulse or even 10whr per pulse.
Full introduction to pulse counting: Building Blocks > Pulse counting
The usual way to do pulse counting on the Arduino is to use the 2 Interrupt pins but this limits us to 2 meters. The following hardware design is for a 12 input arduino based pulse counter that runs firmware that samples all the arduino digital input pins at high sample rate. For full details including arduino source code see: Building Blocks > 12 input pulse counting
Download both the schematic and board file and open in eagle, click on File > Switch to Board to navigate between schematic view and PCB Board view.
- Schematic: 12input.sch
- Board: 12input.brd
Hardware designs (schematics and CAD) files are licensed under the Creative Commons Attribution-ShareAlike 3.0 Unported License and follow the terms of the OSHW (Open-source hardware) Statement of Principles 1.0.