What is it?

WiFi Two Relay with Power Monitoring module is specially designed and brought to market for Wifi enabled Building automation application. This can handle a load at 240 V AC. There are two electomechanical relays mounted on board to control (ON/OFF) external electrical loads from a mobile application or webpages using MQTT/HTTP protocol.Its form factor is just 54X54X21mm. It also has features like, power monitoring and AC virtual switch. The board has programming header (TX, RX, DTRE, RTSE) in compatible to NodeMCU which can be used with Arduino IDE to help the user to program using an external USB-UART converter. It has on-board power supply module which takes standard AC voltage as input and provides required DC voltage as output. The DC voltage is used to power-up Wifi module used on board to establish Wifi communication and monitor & control loads.

Why did you make it?

As most users of home automation need such two relay board for garage as well as socket automation

What makes it special?

• Tasmota compatible: you can directly load tasmota on this board.
• AC to DC Power supply module :AC to DC converter is a switch mode power supply. It rectifies and regulates voltage from 230 V AC to 5 V DC with output current capacity of 500 mA DC. The wattage of on-board power supply is at maximum of 2.5W. The 5V supply is used to power on relay and USB-UATT converter. There is a DC-DC converter on board to regulate voltage from 5 V DC to 3.3 V DC to supply power to Wifi module.
• Wifi Module :Wifi module used on the board is ESP32 with its minimum GPIOs are easily accessible in a header to user for their own application. Wifi module is powered on through 3.3 V DC. It works on both MQTT/ HTTP protocol.
• Electro Mechanical Relay :Electro Mechanical relay is powered by 5 V DC. The AC live powered terminal (NO) is given access to user in a terminal block to control loads. An opto-isolator based driver circuit is used to drive the relay, to create isolation between relay’s AC and DC part. An opto-isolator based AC-DC isolation circuit is used to drive the relay.
• AC Virtual Switch :AC Virtual switch circuit is connected to Wifi module through an opto isolator AC-DC isolation. It gives a ZCD output to Wifi Module to detect the change in status of switch.
• Power Monitoring :Power monitoring block is implemented in the hardware to monitor the consolidated power consumption by the loads. The circuit is based on single phase energy metering IC HLW8012. Which has ability to monitor voltage, current and active power and give the output in the form of pulses. User need to convert these pulse output to appropriate parameters. With these parameters, user can be able to calculate the energy consumption by the loads.
• 3D printed Case : We have developed a 3D case , Comes with a 3D printed case which is glued not snap locked or closed with a screw