1.1 Configuring the ESP8266

The ESP8266 module that comes with the kit is already pre-burned with AT firmware, but you still need to modify its configuration by following the steps below.

  1. Build the circuit.

  2. Open the 1.set_software_serial.ino file under the path of 3in1-kit\iot_project\1.set_software_serial. Or copy this code into Arduino IDE.

    #include <SoftwareSerial.h>
    SoftwareSerial espSerial(2, 3); //Rx,Tx
    void setup() {
        // put your setup code here, to run once:
    void loop() {
        if (espSerial.available()) {
        if (Serial.available()) {
  3. Click the magnifying glass icon (Serial Monitor) in the upper right corner and set the baud rate to 115200. (You may have some printed information like me, or you may not, it doesn’t matter, just go to the next step.)



    • If ready doesn’t appear, you can try to reset the ESP8266 module(connect RST to GND) and re-open the Serial Monitor.

    • In addition, if the result is OK, you may need to re-burn the firmware, please refer to How to re-burn the firmware for ESP8266 module? for details. If you still can’t solve it, please take a screenshot of the serial monitor and send it to sevice@sunfounder.com, we will help you solve the problem as soon as possible.

  4. Click on NEWLINE DROPDOWN BOX, select both NL & CR in the drop down option, enter AT, if it returns OK, it means ESP8266 has successfully established connection with R3 board.

  5. Enter AT+CWMODE=3 and the managed mode will be changed to Station and AP coexistence.

  6. In order to use the software serial later, you must input AT+UART=9600,8,1,0,0 to modify the ESP8266’s baud rate to 9600.