Wattmeter

We need a digital meter designed to meter real power usage (in kWh) and instantaneous readings for power passing through the meter. The meter will have an LCD character display, a momentary reset button, a momentary selection button, a 10 digit keypad (0 – 9) and a relay controlled by the micro controller. The display will normally show the cumulative kWh reading (from the last time the reset button was pressed) and the current instantaneous wattage. The meter will also have an Ethernet interface which provides a basic web page displaying the current readings and allow the cumulative reading to be reset and for the relay to be toggled on and off. We will add username/password authentication to the code for both the website and the LCD display later when we do design on the user interface, so that is not necessary to include, but please design to allow for that. The momentary selection button will put the front LCD display into a “setup” mode where the IP address can be set using the keypad. The meter should be designed with cost of components in mind and be designed to be upgraded later (i.e. The micro controller (or micro controllers) should have plenty of extra ram, speed and extra I/O ports such that the design can be expanded to improve the user interface or add additional buttons or features, etc. Requirements for metering project 1. The meter must handle a full 20 amps continuously. 2. Must work with both 120vac (2 wire + ground) and 120/240v (3 wire + ground) standard AC 50/60 Hz 3. Must accurately meter real power in kWh 4. Must be accurate with an error margin less than 0.1% 5. Must meet IEC1036 specifications for metering power 6. Must correctly measure power returned through ground (attempts to circumvent.) 7. Must be tamper resistant 8. The meter must derive its normal power from the incoming AC power 9. The meter must not lose cumulative kWh reading if power fails 10. Must be micro controller based [login to view URL] micro controller(s) should be available both in din pins and surface mount if at all possible. [login to view URL] have a LCD character display at least 2 lines, 16 chars (we will probably add more text later on.) You are bidding on designing and providing us with schematics and writing working code for the micro controller(s). We will require the source code for the micro controller(s) so we can make changes/upgrades. Please bid according to what you would need to complete this project not according to the budget listed for the project.