Serial communication (Arduino Mega 2560)

Projects Networking, Protocols, and Devices
1

Hi,

I'm using an Arduino Mega Board and I think I'm having some issues with serial communication, but I'm not sure if thats really a problem. Every time I use serial communication (like printing something using serial monitor) I can't really immediately see what I'm printing. I have to wait several seconds or press the reset button of my board. I noticed that the TX LED is blinking until I press the serial monitor (as soon as I press the button the LED turns off I stays like that - and nothing happens on serial monitor - for several seconds or until I press the reset button - and then I can see things on serial monitor).

Is this really an issue or thats common on Mega boards? (I noticed that it doesn't happen on Uno boards).

2

Post your code.

3

I am having a similar problem with Mega 2560. A simple out put on SerialMonitor takes a long time to start. Moreover, the Serial1, Serial2 and Serial3 functions do not give any output on the screen. This delay does not occur with UNO. May we request some response pl. The code i am using is simple from Arduino website as under:-

// Arduino Mega using all four of its Serial ports
// (Serial, Serial1, Serial2, Serial3),
// with different baud rates:

void setup(){
Serial.begin(9600);
Serial1.begin(38400);
Serial2.begin(19200);
Serial3.begin(4800);

Serial.println("Hello Computer");
Serial1.println("Hello Serial 1");
Serial2.println("Hello Serial 2");
Serial3.println("Hello Serial 3");
}

void loop() {}

4

the Serial1, Serial2 and Serial3 functions do not give any output on the screen

Because there's no reason they should, those UARTs aren't connected to anything at all, let alone the USB port.

Is this really an issue or thats common on Mega boards?

No, post you code, something is wrong.

Rob

5

The code is as under:-
void setup(){
Serial.begin(9600);
Serial1.begin(38400);
Serial2.begin(19200);
Serial3.begin(4800);

Serial.println("Hello Computer");
Serial1.println("Hello Serial 1");
Serial2.println("Hello Serial 2");
Serial3.println("Hello Serial 3");
}

void loop() {}

6

Moreover, the Serial1, Serial2 and Serial3 functions do not give any output on the screen.

Are they connected to a serial port on the PC? If so how, because that would require 3 USB->serial converter cables or dongles.

Rob