How to Control Cheap RF Power Plugs with OpenHAB Using ESP8266

Smart outlets are the simplest way to automate your home, but Wi-Fi or Z-Wave models often cost around $40 each, limiting how many you can afford.

That said, you might already own inexpensive RF-based sockets—the kind with custom remotes and channel selectors on the back. While no off-the-shelf smart home hubs support them directly, integrating them into your DIY setup like OpenHAB is straightforward and costs just $10 in parts. I've done this myself successfully.

With extra effort, you can even add other RF devices, like a budget projector screen.

What You'll Need

• ESP8266 NodeMCU v12E dev board (v1 or v3 works too). NodeMCU simplifies Wi-Fi setup. Get a 2-pack for $7 each.
• 433 MHz transmitter/receiver kit (~$3).
• RCSwitch and MQTT libraries, plus my tested code from GitHub.
• An MQTT broker (local or cloud-based).
• RF sockets operating on 433 MHz (check your remote). Mine were a 3-pack from Maplin for ~£20 ($25.89).

If you're new to NodeMCU, install the Arduino ESP8266 plugins following the first part of our ESP8266 introductory guide. You'll also need CH340 drivers: macOS signed drivers here, Windows drivers here.

Stick with Arduino IDE v1.6.5—newer versions caused issues for me. Add the libraries from my GitHub download to your Arduino/libraries folder.

Remove any existing PubSubClient or MQTT library; the included one is the only reliable option I've tested extensively with NodeMCU.

Basic Arduino knowledge assumed—see our Arduino Programming for Beginners guide if needed.

RF Sniffing (Optional)

Skip if using standard DIP-switch or rotary sockets (supported out-of-box). For custom remotes, sniff codes first.

Load Examples > RCSwitch > ReceiveDemo_Advanced. Change:

mySwitch.enableReceive(0);

to:

mySwitch.enableReceive(2); // Receiver on GPIO 2 / D4

Wire the receiver (longer board, components facing you):

• Far right: GND to NodeMCU GND.
• Far left: VCC to NodeMCU VIN.
• Middle pins: Signal to D4 (either works).

Upload, open Serial Monitor, press remote buttons. Note decimal code, bit length, pulse length, protocol.

For my projector screen:

• SCREEN UP: 8694273/24 bits; Pulse length: 355-356; Protocol: 1
• SCREEN DOWN: 8694276/24 bits; Pulse length: 355-356; Protocol: 1

Testing the Transmitter

Wire the transmitter (square board): Pin labels are misleading! VCC is center; 'A LITTLE' is backwards 'DATA'. DATA to D4, VCC to VIN, GND to GND. (Disconnect receiver.)

Load Examples > RCSwitch > TypeB_WithRotaryOrSlidingSwitches. Change:

mySwitch.enableTransmit(10);

to:

mySwitch.enableTransmit(2);

For Type B (rotary/sliding) sockets:

mySwitch.switchOn(1, 4);
mySwitch.switchOff(1, 4);

1=channel (top dial), 4=socket (bottom dial). Up to 16 sockets.

For my screen (custom pulse):

// Note: Screen needs two presses
void screenUp() {
  mySwitch.setPulseLength(358);
  mySwitch.send(8694273, 24);
  delay(2000);
  mySwitch.send(8694273, 24);
}

void screenDown() {
  mySwitch.setPulseLength(358);
  mySwitch.send(8694276, 24);
  delay(2000);
  mySwitch.send(8694276, 24);
}

Set pulse before protocol to avoid overwriting. Test thoroughly.

Control via MQTT

Open mqtt_rcswitch.ino from GitHub. Update Wi-Fi SSID/password, MQTT server (see OpenHAB Beginners Guide Part 2 to set up MQTT in OpenHAB). Tuned for Type B sockets; adapt for DIP as needed.

Key: callback() handles MQTT:

void callback(String topic, String payload, ...) {
  if (topic.indexOf("switch") >= 0) {
    int channel = getValue(topic, '/', 3).toInt();
    int plug = getValue(topic, '/', 4).toInt();
    if (payload == "ON") mySwitch.switchOn(channel, plug);
    else mySwitch.switchOff(channel, plug);
  } else if (topic.indexOf("screen") >= 0) {
    if (payload == "UP") screenUp();
    else if (payload == "DOWN") screenDown();
  }
}

Commands:

livingroom/control/switch/X/Y  (payload: ON/OFF)

livingroom/control/screen  (payload: UP/DOWN)

Test with MQTT client before OpenHAB.

Integrate with OpenHAB

Add items:

Switch CinemaScreen "Screen" (Cinema) { mqtt="> [broker: livingroom/control/screen:command:ON:DOWN], > [broker: livingroom/control/screen:command:OFF:UP]" }
Switch Switch41 "Switch41" (Cinema) { mqtt="> [broker: livingroom/control/switch/4/1:command:ON:ON], > [broker: livingroom/control/switch/4/1:command:OFF:OFF]" }
Switch Switch42 "Switch42" (Cinema) { mqtt="> [broker: livingroom/control/switch/4/2:command:ON:ON], > [broker: livingroom/control/switch/4/2:command:OFF:OFF]" }

Control RF devices from OpenHAB! Range covered my house; add repeaters if needed. Sockets don't report state—avoid physical remote to keep sync.

Questions? Comment below—happy to help. Improve the code? Pull request welcome.