27976 Parallax Inc, 27976 Datasheet - Page 5

• Manufacturer Part Number: 27976
• Description: MODULE SRL LCD 2X16 NON-BACKLIT
• Manufacturer: Parallax Inc

Specifications of 27976

• Display Mode: Transflective
• Interface: Serial
• Display Type: STN - Super-Twisted Nematic
• Number Of Digits/alpha: 32
• Outline L X W X H: 80.00mm x 36.00mm x 21.00mm
• Viewing Area: 61.00mm L x 15.70mm W
• Backlight: Without Backlight
• Display Format: 16 x 2
• Character Format: 5 x 8 Dots
• Voltage - Supply: 5.0V
• Operating Temperature: -20°C ~ 70°C
• Character Count X Line: 16 x 2
• Module Size (w X H X T): 38 mm x 80 mm
• Features: Serial LCD
• Fluid Type: STN Positive
• Voltage Rating: 5 VDC
• Operating Temperature Range: - 20 C to + 70 C
• Backlight Type: LED Yellow-Green
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Dot Size: -
• Character Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Baud Rate Setup
After connecting the Serial LCD, you will need to select the baud rate at which you are going to send it
data. You have three choices: 2400, 9600, and 19,200 baud. To set the baud rate, move the dip
switches on the back of the LCD into the correct positions according to the table next to the switches,
which is also repeated below:
As you can see from the table, there is also a fourth choice called Test. Now that you’ve connected the
power, use this Test mode to confirm that the power and ground to the LCD are hooked up correctly
before you send it any data. Move the dip switches to the Test setting and turn on the power. The LCD
display should turn on with the backlight on (models 27977, 27979) and display the following text:
If you don’t see the text at first, try adjusting the LCD contrast by turning the pot labeled “Increase
Contrast” with a screwdriver. Turn it in the direction of the arrow to make the characters show up more
clearly. If you still don’t see the characters, go back and check your electrical connections and try again.
Once you’ve successfully completed test mode, move the dip switches to the correct positions to select
the baud rate you want to use for your application.
Displaying Text
Now that the LCD is set up, it’s time to start sending text to the display. To display a character of text on
the Serial LCD, simply send the ASCII code of that character to the Serial LCD over the serial port at the
correct baud rate.
When a character is received, the Serial LCD displays that character at the current cursor position and
then moves the cursor one position to the right. When you first turn on the LCD, the cursor is in the
leftmost position on the top line, as you might expect. The short bar on the bottom of the character
shows where the cursor is positioned currently.
Once you’ve sent a full line characters to the LCD, you will notice that the cursor automatically wraps
around to the leftmost position of the second line, just like the text in a book. The text will wrap like this
at the end of every line, with the end of the bottom line wrapping back around to the top line of the LCD.
The text will never “run off” the display; you’ll always see all of the characters you send.
Try the following code on your BASIC Stamp 2 to send a text string to the LCD display. First, set the
baud rate on your Serial LCD to 19,200. Then, load the code below into your BASIC Stamp 2 and run it.
You will see the text string show up and wrap to the second line of the display.
©Parallax, Inc. • Serial LCD (#27976/27977/27979) • v2.0 7/26/2006 Page 5 of 11
19.200
MODE
2,400
9,600
Test
SW1
OFF
OFF
ON
ON
SW2
OFF
OFF
ON
ON
Parallax, Inc.
www.parallax.com