WiFi AC Switch for NodeMCU
The WiFi AC Switch combined with NodeMCU (ESP8266) enables you to easily build home automation and IoT projects that allow you to turn on or off AC line power devices such as lights and fans using WiFi connectivity. The WiFi AC Switch can be considered an add-on for the popular, low cost, and Arduino enabled NodeMCU WiFi development board with the ESP8266 SoC. The NodeMCU connects to the WiFi AC Switch via two 15 pin female headers so it can easily be connected and removed (similar to an Arduino Shield). You can even order a NodeMCU with the WiFi AC Switch (see options).
Note that there are various versions of the open source NodeMCU out there, the WiFi AC Switch board was made for NodeMCU versions with 23 mm spacing between the pin headers and 15 pins on each side. You control switching the AC power on an off with GPIO pin 4 (high closes switch and low opens switch). All other NodeMCU pins can be accessed via the 2.54 mm spaced pin holes on either side of the NodeMCU header on the WiFi AC Switch. One great feature of the WiFi AC Switch is it has a built-in AC to DC power supply that takes power from the input AC line power signal. This means you do not have to worry about a separate plug or battery back to power the WiFi AC Switch. The following are some important specs to consider on the WiFi AC Switch:
- It has both 5V and 3.3V outputs for powering additional hardware or sensors
- The AC Switch is made for AC voltage levels between 12Vrms and 150Vrms
- The AC power has an inline fast-blow fuse that can handle up to 2As and 250Vpeak
Please note that AC line power can kill and you should only work with it if you know and understand the dangers. Since the WiFi AC Switch is a development board it has some exposed metal connectors that could have live AC power on them so handle with caution!
You can find a video demonstration of the WiFi AC Switch in action as well as connection instructions in the "Additional info" section. The WiFi AC Switch comes with all surface mount components soldered on. The base version comes without the through hole parts soldered on (power supply, fuseholder, screw terminal connectors, females headers, etc). There is an option to have all parts solder on for an extra $3. You can also get a discounted NodeMCU with the WiFi AC Switch as an option.
To use the WiFi AC Switch:
- First cut the two wire cord of the AC device you want to control
- Strip off about 1/4" to 1/2" inches from the insulation of the four wires
- Insert the two stripped wires from the power source into the screw terminal connector labeled "AC_IN". Note that the order of the two wires in the screw terminal should not matter, but try to be consistent between "in" and "out"
- Insert the two stripped wires from the load into the screw terminal connector labeled "AC_OUT"
- Be sure that wires are firmly secured by the screw terminals. If the wire is braided, be sure that no loose wires are creating a short between the connectors