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Arduino Wi-Fi AC Energy Meter

Introducing an accurate AC energy meter that is Wi-Fi enabled. The meter has a power range of 5W to 3.2kW and measures True RMS volts, True RMS current, Real power, Power factor, kilowatt-hours and includes a scrolling plot of AC voltage variation over time. All data is sent once every second via Wi-Fi to a free Android App called “RoboRemo”. For this project we will utilize an Arduino Nano, an 8266-01 Wi-Fi module and an ACS712 current sensing module. This instructable will explore the theory behind AC power measurements , explain how the circuit works and show how to download and customize the RoboRemo application.

- Arduino Nano - Note: an Arduino UNO or MEGA can be substituted
- ESP8266-01 module
- ACS712-20 - Current sense module
- 5V Power Supply (500mA min) - I used a small 5V USB Charger
- LMC7111 - Op-Amp rail to rail Note: LM321,LM324 or M358 can be substituted limiting the dynamic range of ACS712
- LM78M33 - 3.3V regulator SOT-223 package Note: Any suitable 3.3V regulator can be substituted
- 220k resistor 1Watt
- 10K resistor (x5)
- 2.7k resistor (x2)
- 1k resistor (x3)
- 1uF electrolytic capacitor (x2) 10 volts or greater
- 100nF ceramic capacitor (x3)
- Pin Header strip - Female
- Terminal block 5mm 2 pin (x4)
- AC lamp cord wire
- small guage hook-up wire”

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