Serial3 of arduino mega not working....

Projects Networking, Protocols, and Devices
1

I have connected RS232 to TTL conventer to arduino mega's pin 14 and pin 15. And simply writes data using serial3 library. But it does not work.

Is there any additional requirement to use this library. Here is my code.

void setup() 
{
  // put your setup code here, to run once:
  
  Serial3.begin(9600);
  Serial3.println("start serial3");
}

void loop() {
  // put your main code here, to run repeatedly:

}
2

jigisha:
I have connected RS232 to TTL conventer to arduino mega's pin 14 and pin 15. And simply writes data using serial3 library. But it does not work.

How do you know it does not work?
Where are you expecting to see the output from your Serial3.println() ?

You have only told us half of the story. What is at the other end of the RS232 cable.

...R

3

Other end is connected my PC and i check my output from Acessport software which is serial port monitoring tool.

4

What did you do with the RTS and CTS pins?

5

That is unconnected. In my 232 to TTL convereter only 4 outputs there rxd, txd , VCC and grd.

6

jigisha:
That is unconnected. In my 232 to TTL convereter only 4 outputs there rxd, txd , VCC and grd.

Then the converter device is not capable of hardware flow control?

7

Might be yes...:frowning: dont have that much knowledge about hardware and flow control.

8

It is rare that a PC has a DB9 connector. Is that how you are connecting the converter to the PC? Or are you using a RS232 to USB converter?

9

Yes using RS232 to USB conventer.

10

Are you certain the RS232 to USB converter is working? At this point, would get out my oscilloscope.

11

That must be working because when i write code using USART function receiving and transmission happened..

12

jigisha:
That must be working because when i write code using USART function receiving and transmission happened..

How are you determining that? Do you have a loopback plug?

13

The device manager must be used to match the baud values and turn off flow control.

14

jigisha:
Other end is connected my PC and i check my output from Acessport software which is serial port monitoring tool.

I have read through the rest of this Thread and I am still confused.

Please draw a simple diagram showing how everything is connected and post a photo of the diagram.

Please tell us what program you are using on the PC to view the output from Serial3.

Are you able to view the output if you use Serial on the Mega?
If so, what program on the PC are you using for that?

...R