To link with iot webserver "iotalways.com" you need to make an account to generate an api key free and insert the key into the code mentioned below. the hardware of this project includes an Arduino Uno or AVR atmega328 and ESP8266 to measure Voltage & current along with a power and entry No. if you need step by step guide of esp8266 commands then click here. the detailed code is given below you just need to replace an api key and then login with your account. the resfresh rate is about 6 seconds, after loging into your account you have to configure the account by changing necessary parameters according to your requirements.
ADC0 is configured to measure voltage, while ADC1 is configured to measure Current use a CT or ACS712-xx, how ever power is calculated as product of ADC0 and ADC1, an auto increment entry is also added so that total number of entries can be monitored.
atmega328p\arduino can be used here, it is configure in software serial mode portd.5 and portd.6 is configure for serial receptiona nd transmission respectively with baud rate of 9600bps.ESP8266 is used here. this module first must be configured to get AT commands then this code can be used in arduino UNO or atmega328p chip. you can directly measure the voltage with ESP8266 module with its builtin ADC channel(Method will be published soon.
Note:ESP8266 is based on 3.3V you need a level converter to attach with 5V arduino
IoT Volt amppere measurement code