serial communication using tx and rx pins

hi guys,
im still new with arduino , thus i have couples of queries regarding serial communication with other devices.

1)will arduino hardware uart able to communicate at 1MBps baud rate rather than 9600?
2)is it possible to change the uart into half duplex asynchronous serial com?
3)which command should i use if i wan to send packet command?

1)will arduino hardware uart able to communicate at 1MBps baud rate rather than 9600?

I don’t think so. I guess (not sure) that 115200 is the maximum.

2)is it possible to change the uart into half duplex asynchronous serial com?

Yes. You can handle it programatically.

3)which command should i use if i wan to send packet command?

You should have a sketch with something similar to it:

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

 void loop()
 {
   Serial.println("Hello World");
  }

any ideal/tutorial/links?

  1. how to change make arduino communicate at 1Mbps?as i read from other website which stated that it can communicate at this speed.
    2)how to change serial com to ttl half duplex programatically?
  2. is the rx and tx pin same as those in the usb port?

You are welcome.

Short answers for short questions:

  1. Read Using the USART with AVR-GCC and ATMega8/ATMega168 data sheets.
  2. If you are talking about converting serial signals to RS232 you need hardware. MAX232 and some capacitors will do the work.
  3. If I am not wrong, Yes. Digital pins 0 and 1 are the same going to USB port.

Juan C.

If I am not wrong, Yes. Digital pins 0 and 1 are the same going to USB port.

you are not wrong :wink:

im back…i was in the ladyada’s forum.i somehow got my answers for my previous questions.

someone told me that arduino can communicate with a device at 1Mbps,but i will try out first. Forget about the half duplex issues, i guess that i will use a device that can communicate at ttl full duplex uart with arduirno.BTW it can be done right?

the next problem i might be facing is that a few identical devices will be connected in daisy chain manner to the tx and rc pins.will arduino be able to communicate with those using multi drop full duplex uart serial communication method?