IOT based 4 Channel Relay module with ESP8266 ESP-01 For IOT Smart Home Phone APP Controller

Function features :

1.on board high quality MCU and ESP-01WIFI module

2.two working mode :

Mode 1:cellphone carry on wifi module directly

Mode 2: cellphone and wifi module carry on router together

Additional function :work as USB module when disconnect ESP-01 module


3. Transmission distance:

(1) the open environment, the mobile phone when carrying on the WIFI module maximum transmission distance of 100 m;
(2), when the WiFI module and cell phone carrying on the router at the same time the signal transmission distance depends on router signal


4. Use the Smartconfig technology to complete the configuration of the account and password of the esp-01 WIFI module on the mobile APP. The configured account and password will be memorized after power off

5. The board contains 5V,10A/250V AC 10A/30V DC relay, which can continuously absorb 100,000 times, with the protection of diode current and short response time.

6. With mode option and working statue LED indicator

7. With 4 isolator and strong anti interference ability

8. Reserved UART debug interface and MCU download port for program



Hardware introduction :

Board size 60*63mm

1interface on board 

IN+IN-5V voltage input 

5VGNDTXRXUART serial port PIN 

SWIMPIN8NRSTreserved MCU download port 

Button S1change mode default mode is mode 1

Button S2reset

LED D1/D2/D3/D4red ):relay working LEDLED on when relay is on

LED D7red ):indicator for mode 1

LED D5blue):indicator for mode 2

LED D6green ):work statue indicator exact details as below 


(1)When extinguished, it is being configured or disconnected from the router.

(2)0.5s fast blinking represents cellphone app is configuring WIFI account and password for ESP-01 module

(3) 2S slow blinking to configure finished ,and wait for connection with cellphone by TCP

(4)LED always on represents TCP connections with mobile phone successfully


Connection for reserved two cap jumper :

Generally ,insert them to bottom ,that is RX to RX1,TX to TX1 .Insert them to upper ,when use it as USB module


COM1 COM2 COM3 COM4 Common terminal 

NC1 NC2 NC3 NC4 normal close

NO1 NO2 NO3 NO4 normal open



Control command for relay hex format ):

Open relay 1 A0 01 01 A2

Close relay 1 A0 01 00 A1

Open relay 2 A0 02 01 A3

Close relay 2A0 02 00 A2

Open relay 3 A0 03 01 A4

Close relay 3 A0 03 00 A3

Open relay 4 A0 04 01 A5

Close relay 4 A0 04 00 A4

 Tips: all of the following are used to control the first 2 relay in the mobile phone APP. The third and fourth way are the same, except that the relay control instructions are different.

 2get ready for the following software and tools 

(1)5V/1A adaptor and connect to IN+ and IN-

(2)Install APP “EspTouch_Demo” android version to configure wifi account and password for ESP-01 module on the first time of mode 2