As the the name implies, ESP8266 5V Wi-Fi relay switch modules are Wi-Fi enabled, relay power switches. The module also includes a detachable ESP8266 micro-controller board. The main function of these boards are to be used as wireless power switches accessible from Smartphones.
The ESP8266 5V Wi-Fi relay switch modules are small, inexpensive modules measuring in at 45 x 28 x 20 mm. It needs 5V DC to operate. Similar to other 5V relay switch modules, the on-board relay can tolerate 110 – 250V AC or up to 30 V DC at 10A. The module is also equipped with serial port debugging pins and has a build in flyback diode to protect the circuit from voltage spikes.
ESP8266 5V Wi-Fi Relay switch module specifications
DC Pins: 3. IN, VCC, GND / S, +, – (marked).
AC Sockets: 3. NO (normal open), COM, NC (normal closed) (marked)
Working voltage: 5 V DC (connected via screw terminal connectors) – 12V DC modules also available
Serial port debugging pins: Tx, Rx, Vcc, GND (marked)
On-board LED: module dependent
Size: 45 x 28 x 20 mm (L,W,H). Might be module dependent.
Pin size: male, 5 x 2.54 mm
The ESP8266 5V Wi-Fi relay switch module is shipped with a detachable ESP8266 micro-controller board. The module is manufactured to use serial commands between the ESP8266 and the relay (i.e. it does not function via traditional digital pin triggering). The module automatically reduces the input voltage of the ESP8266 to 3.3V DC.
Setting up the ESP8266 5V Wi-Fi relay switch module
Out of the box, ESP8266 5V Wi-Fi relay switch modules need to be ‘programmed’. Depending on its purpose/desired mode (see below), serial commands need to be send to the module using serial debugging software (see below) via the serial debugging pins. The pins are connected to a FTDI programmer (USB-TTL UART module) which connects to a PC via an USB port.
ESP8266 5V Wi-Fi relay switch modules can be used as stand-alone Wi-Fi connected devices (AP mode) or can be connected (on)to a local area network (STA mode). With AP mode up to 5 connections can be made at the same time and it is said that a connection can be made from as far as 400 meters away. Either way, connection and communication to the module is made by using a TCP connection App (such as EasyTCP for Android). Baud rates of 115200 or 9600 can be used. The mode settings are not stored and needs to be re-‘programmed’ after power is disconnected.
To get started with the ESP8266 5V Wi-Fi relay switch modules you will need
- ESP8266 5V Wi-Fi relay switch module (buy 1 from BangGood | buy 3 from BangGood)
- A Personal Computer to open and use the following recommended documentation (incl. serial debugging software)
- FTDI programmer (buy 1 from BangGood)
- mini-B USB cable (buy 1 from BangGood)
- Breadboard (buy 1 from BangGood | buy 5 from BangGood)
- 5V DC 2A power supply converter module (buy 1 from BangGood | buy 3 from BangGood | buy 5 from BangGood)
- 20cm female to female jumper cable dupont wire set (buy 1 from BangGood)
Although proper instructions might be hard to come by, ESP8266 5V Wi-Fi relay switch modules are still inexpensive and small enough to incorporate into DIY projects. They are great to be used as Smartphone operated trigger switches for high voltage units like lights in Home automation projects.