ESP8266 SENDING WRONG DATA

Projects Networking, Protocols, and Devices
1

This project displays the serial communication between esp8266 esp-01 and arduino uno. I uploaded the following code to esp8266

void setup() {
Serial.begin(9600);
}

void loop() {
if(Serial.available())
{
if(Serial.read()=='1')
Serial.write(5);
}
}

the connections are:-

Arduino ESP8266
Rx-------------->Rx
TX--------------->TX
Gnd,RESET-------------->Gnd,GP0
3.3v--------------->CHPD,VCC

The code I uploaded to arduino:-

#include <SoftwareSerial.h>
SoftwareSerial esp(4,3);
void setup() {
Serial.begin(9600);
esp.begin(9600);
}
void loop() {
esp.write(1);
Serial.println(esp.read());
delay(1000);
}

The Connections are:-

Arduino ESP82666
D4--------->RX
D3--------->TX
GND-------->GND
3.3v--------->Vcc,CHPD

The Expected output was 5 but in the serial monitor I am getting -1 as output.

2

RX to TX

and you want
Serial.print(5);

and
if (Serial.available()) {
in esp8266 sketch

3

Serial.print() is there in the code of the arduino because it is connected to the serial monitor. Esp8266 is not connected directly to the serial monitor so why should i put Serial.print() in the esp8266 code?

4

santam:
Serial.print() is there in the code of the arduino because it is connected to the serial monitor. Esp8266 is not connected directly to the serial monitor so why should i put Serial.print() in the esp8266 code?

you have write(), not print(). write(5) will print a character with ascii code 5. it is a not visible control character. print(5) will print 5 as text.

5

santam:
This project displays the serial communication between esp8266 esp-01 and arduino uno. I uploaded the following code to esp8266

the connections are:-

Arduino ESP8266
Rx-------------->Rx
TX--------------->TX
Gnd,RESET-------------->Gnd,GP0
3.3v--------------->CHPD,VCC

For serial connections you connect the receiver port of one to the transmitter of the other, your connections should look like
the connections are:-

Arduino ESP8266
Tx-------------->Rx
RX--------------->TX
Gnd,RESET-------------->Gnd,GP0
3.3v--------------->CHPD,VCC