Serial Monitor sending data weird 每

Projects Programming
1

Hello :slight_smile:
i wanted to test if my ESP8266 WIFI module is working correctly. Because i dont have any usb-uart module, i used my leonardo to read what's receiving and send over serial monitor. Code:

void setup() {
聽 // put your setup code here, to run once:
聽 Serial.begin(115200);
聽 Serial1.begin(9600);
}

void loop() {
聽 // put your main code here, to run repeatedly:
聽 while(Serial.available()) Serial1.write(Serial.read());
聽 while(Serial1.available()) Serial.write(Serial1.read());
}

the Module is connected to the uart pins on the leonardo, with a voltage divider on rx. when i remove the power and apply it again, i get the normal boot text.

*weird characters 
[Vendor:www.ai-thinker.com Version:0.9.2.4]

ready

but if i enter "AT" and press send, i sends "AT媒". And both, rx and tx pin light up.

Whats the problem?

thanks

Straw

2

That funny y symbol often means that the baudrate of the Serial Monitor does not match the baud rate of the Arduino program.

...R

3

double checked, tripple checked, changed baudrate in sketch and in monitor. still same

828脳492 17 KB

Tested every baudrate, still same y.

~Straw

4

Looks like the ISO Latin 1 character for character code 0xFD.

If you use any other command does it also get echoed with that character after it?

5

What happens if you change the Serial.write() to Serial.print()?

聽 while(Serial.available()) Serial1.print(Serial.read());
聽 while(Serial1.available()) Serial.print(Serial1.read());
6

econjack:
What happens if you change the Serial.write() to Serial.print()?

  while(Serial.available()) Serial1.print(Serial.read());

while(Serial1.available()) Serial.print(Serial1.read());

with print im getting decimal code back

7

One more try, and tell me what decimal codes you are seeing:

聽 while(Serial.available()) Serial1.print((char) Serial.read());
聽 while(Serial1.available()) Serial.print((char) Serial1.read());
8

econjack:
One more try, and tell me what decimal codes you are seeing:

  while(Serial.available()) Serial1.print((char) Serial.read());

while(Serial1.available()) Serial.print((char) Serial1.read());

Well now it outputs normal characters. but somehow it now doesnt reports the last command i send. after sending "AT" nothing happens, there is no "AT" in the Serial monitor.

~Straw

9

OK went over to a friend and lend his uart module. when typing at it works. So it can only be a fault of my wiring, of the code or, lets hope not because its new, of my arduino

~Straw

10

OK, swapped out the resistors, now it works:)

11

The y with the dots on top has extended ASCII code 0xFF (255 in decimal) and indicates a value of -1 being read. That is either caused by a 'real' end of file condition or bad wiring.

kind regards,

Jos