Arduino Mega 2560 + MAX 323 send command problem

Projects Interfacing w/ Software on the Computer
1

Hi, all

I use Mega 2560+MAX323 to send command to control LCD monitor.
I send a "Turn On" command, code was listed below:

void setup()
{
Serial.begin(115200);
pinMode(13, OUTPUT);
}

void loop()
{
Serial.print(119, BYTE);
Serial.print(177, BYTE);
Serial.print(128, BYTE);
Serial.print(0, BYTE);
Serial.print(0, BYTE);
Serial.print(70, BYTE);
delay(10000);
}

I has a problem....
Command is working, but only under Mega2560 plugging USB to computer first time....
It's not working even if I press "Reset" button.

Is my coding syntax wrong?
BTW, if command is successful, LCD monitor will return 6 bytes message.
Should I clean the buffer?

Thank you.

Greg Lu

2

That code send characters to the PC over the USB connection.

Where is it that you talk to an LCD?

Rob

3

but only under Mega2560 plugging USB to computer first time...

That seems crucial to your problem but the words make no sense.
Do you mean it works with a PC monitor but not standalone?
How are you powering it stand alone?