Serial LCD from Parallax

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi to everyone!
i have the serial LCD from Parallax:
http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/27976/List/0/SortField/4/ProductID/52/Default.aspx

it looks very simple to connect, but when i write only "Hello World" with an example sketch, it doesn't work! it continues to display the default text "Parallax, inc. www.parallax.com".

Can anyone help me, please?

Here the sketch for example:

void setup() {
  // open the serial port at 9600 bps:
  Serial.begin(9600);
  pinMode(1,OUTPUT);
  Serial.print(12, BYTE);
  Serial.print("Hello world");
}

void loop() {
}

Help me!!!

Bye
Angelo

2

How have you got your serial port wired?
Normally, I'd expect to see the output of that sketch on the serial monitor.
I'd try not using the hard serial port, but use one of the soft serial libraries, and a different output pin.

3

It looks like the dip switches on the back are both in the off position, which is testmode, and will display the text you describe.

you should have switch one off and switch 2 on to set it up to the 9600 baud you have in your Arduino code.

4

Ok, thanks for your answers...
I turned off the switch1 and on the switch2 to have the baud rate on 9600, but the problem remains!
I could try the way of using the softserial instead of hard serial port, but i can't understand how it's possible that the lcd doesn't work when i did all the things to set it up...i don't know!!

5

Have you tried sending:

Serial.print(65, DEC);

which should then send a capital A

Mowcius

6

Yes, i've tried, but it's the same! The LCD continues to display the default text without any changes!
The test with the softserial doesn't work!

:frowning:

7

Hmm, ok, have you tried different cominations of the DIP switch positions?

Mowcius

8

Yes, i tried all the combinations to try different baudrate, but the result it's the same: the default text remains on the LCD! >:(

However, I think it's a factory problem, because after the test (switch1 off, switch2 off) and after setting the baud rate at 9600 (switch1 off, switch2 on), the screen should be without text!!

9

Yeah, after all that it sounds like it is just a naff display, contact them and they should just be able to give you a refund.

Mowcius

10

try a small delay between sending to the display like:

Serial.print(12, BYTE);
delay(50);
Serial.print("Hello world");

Maybe it needs a little setup time ??

11

I checked the basic stamp sample code from parallax they have a 100ms delay, so try that.

12

Just to update this entry - adding the delay works. So here are directions for connecting the Parallax Serial LCD with Arduino.

Parallax Part Number:
Standard 27976
Backlit 27977

Connect 5V and Ground to Serial LCD
Connect Pin D1 of Arduino to RX Pin on Serial LCD
Set Dip Switch 1 on Serial LCD to OFF
Set Dip Switch 2 on Serial LCD to ON

void setup() {
  Serial.begin(9600);
                 
  Serial.print(12, BYTE);  //Clear Screen
  delay(5);
  Serial.print("Hello world");

}

void loop() {
}

I don't know how to properly initialize the screen. So, it can sometimes take a few writes to the display to get it sorted out, so I got around this by just printing "initialize" a few times before I started printing data.

More info: http://www.parallax.com/dl/docs/prod/audiovis/SICSerialLcd.pdf

13 
  Serial.begin(9600);
  pinMode(1,OUTPUT);

The Serial instance owns pin 1. You should not be messing with the mode for pin 1.