Base code for shelly EM energy meter

Shelly EM is a impressive mini device that comes with the following features:

• I2C RTC based on PCF85363A
• I2C energy meter based on AD7953
• Relay
• Button
• LED
• Esp 8266EX chip with 4Mb of flash

This code serves as a buliding block to develop whatever you want on top of this great device.

Check out the manufacturer, shelly for features and hardware details.

• AC mains can kill you. You wont be able to undo any mistake after you're dead.
• You CANNOT connect shelly to mains AC and to the programming pins at the same time.
• Disconnect the device from any mains before program it with this firmware
• provide your own WiFi, MQTT and Emoncms configuration and upload the firmware as a starting point.
• Check serial UART for IP address, check if Emoncms and MQTT is working, disable the features you don't want on the code.
• After everything is tested disconnect the programming pins and connect to AC mains and test again if the device is working properly.
• From there you can change the code and do OTA updates to the ESP8266 using the url: http://<ip_of_device>/update

This code has the following features:

• press button for 2 seconds to toggle relay.
• LED follows Relay status
• Communcate with ADE7953 and PCF85363A via I2C
• Publish energy readings to emoncms server every 10s
• Publish RTC time and energy readings to MQTT every 1s
• WebUpdater.ino code included for easy updates OTA - http://<IP_address>/update

Have fun!

If you find any improvements, like better calibration procedure or find any problems please open a issue.