Difference between revisions of "Serial enabled LCD backpack"

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m (corrected small issue)
(→‎Code: added functions)
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=== Code ===
 
=== Code ===
 
{{expand section}}
 
{{expand section}}
 +
 +
<pre>
 +
<source lang="C">
 +
//SerialLCD Functions
 +
void selectLine(int line) {
 +
  serCommand(); //command flag
 +
 
 +
  switch( line ){
 +
    case 0:
 +
      lcd.print(128,BYTE); //puts the cursor at line 0 char 0
 +
      break;
 +
    case 1:
 +
      lcd.print(192,BYTE); //puts the cursor at line 0 char 0
 +
      break;
 +
    case 2:
 +
      lcd.print(148,BYTE); //puts the cursor at line 0 char 0
 +
      break;
 +
    case 3:
 +
      lcd.print(212,BYTE); //puts the cursor at line 0 char 0
 +
      break;
 +
    default:
 +
      selectLine(0); //defaults back to line 0
 +
      break;
 +
  }
 +
}
 +
 +
void goTo(int position) { //position = line 1: 0-19, line 2: 20-39, etc, 79+ defaults back to 0
 +
  if (position<20){ Serial.print(0xFE, BYTE);  //command flag
 +
                Serial.print((position+128), BYTE);    //position
 +
  }else if (position<40){Serial.print(0xFE, BYTE);  //command flag
 +
                Serial.print((position+128+64-20), BYTE);    //position
 +
  }else if (position<60){Serial.print(0xFE, BYTE);  //command flag
 +
                Serial.print((position+128+20-40), BYTE);    //position
 +
  }else if (position<80){Serial.print(0xFE, BYTE);  //command flag
 +
                Serial.print((position+128+84-60), BYTE);    //position             
 +
  } else { goTo(0); }
 +
}
 +
 +
void clearLCD(){
 +
  Serial.print(0xFE, BYTE);  //command flag
 +
  Serial.print(0x01, BYTE);  //clear command.
 +
}
 +
 +
void backlightOn(){  //turns on the backlight
 +
    Serial.print(0x7C, BYTE);  //command flag for backlight stuff
 +
    Serial.print(157, BYTE);    //light level.
 +
}
 +
 +
void backlightOff(){  //turns off the backlight
 +
    Serial.print(0x7C, BYTE);  //command flag for backlight stuff
 +
    Serial.print(128, BYTE);    //light level for off.
 +
}
 +
 +
void backlight50(){  //sets the backlight at 50% brightness
 +
    Serial.print(0x7C, BYTE);  //command flag for backlight stuff
 +
    Serial.print(143, BYTE);    //light level for off.
 +
}
 +
 +
void serCommand(){  //a general function to call the command flag for issuing all other commands 
 +
  Serial.print(0xFE, BYTE);
 +
}
 +
</source>
 +
</pre>
  
 
== See also ==
 
== See also ==

Revision as of 19:51, 20 January 2010

The Serial Enabled LCD Backpack (SerLCD) is a product made by Sparkfun that allows control of a parallel based LCD over a single-wire serial interface. The SerLCD backpack takes care of all the HD44780 commands allowing seamless integration with any digital device that can communicate via a TTL serial line. The device is designed to handle a wide range of TTL serial baud rates, and currently supports 16 or 20 character wide screens with 2 or 4 lines of display.

Serial Enabled LCD Backpack (SerLCD)

A version 2 backpack.

General Information
Manufacturer SparkFun Electronics
Current Version 2.5
Average Price $17
Specifications
Input Voltage 5 V
Max Input Voltage 5.5 V
Current Draw 3 mA w/o backlight
60mA w/ backlight
Clock Speed 8 MHz
Number of Positions 16
Measurements
Length 1.75 inches
Width 0.56 inches



Communication

Communication with SerLCD requires 5V TTL serial at a default baud rate of 9600bps with 8 bits of data, 1 start bit, 1 stop bit, and no parity (8-N-1). You can adjust the baud to any standard rate between 2400 and 38400bps. The power, ground and RX pins are all broken out to a 3.5mm pitch screw terminal.

Pinout

  1. Ground (VSS)
  2. +5V (VDD)
  3. Contrast adjustment (V0)
  4. High/Low Register select signal (RS)
  5. High/Low Read/Write signal (R/W)
  6. High/Low Enable signal (E)
  7. High/Low bus line (DB0)
  8. High/Low bus line (DB1)
  9. High/Low bus line (DB2)
  10. High/Low bus line (DB3)
  11. High/Low bus line (DB4)
  12. High/Low bus line (DB5)
  13. High/Low bus line (DB6)
  14. High/Low bus line (DB7)
  15. +4.2V for LED (A)
  16. Power supply for BKL 0V (K)

Features

  • New PIC 16F688 utilizes onboard UART for greater communication accuracy
  • Adjustable baud rates of 2400, 4800, 9600 (default), 14400, 19200 and 38400
  • Operational Backspace
  • Greater processing speed at 10MHz
  • Incoming buffer stores up to 80 characters
  • Backlight transistor can handle up to 1A
  • Pulse width modulation of backlight allows direct control of backlight brightness and current consumption
  • Potentiometer to control contrast
  • All surface mount design allows a backpack that is half the size of the original
  • Faster boot-up time
  • Boot-up display can be turned on/off via firmware
  • User definable splash screen

Arduino

SerLCD works seamlessly with the Arduino with the option of using the default serial transmission port, or by creating a SoftwareSerial port.

Code

Wiki letter w.png This section requires expansion. 
<source lang="C">
//SerialLCD Functions
void selectLine(int line) {
  serCommand(); //command flag
  
  switch( line ){
    case 0:
      lcd.print(128,BYTE); //puts the cursor at line 0 char 0
      break;
    case 1:
      lcd.print(192,BYTE); //puts the cursor at line 0 char 0
      break;
    case 2:
      lcd.print(148,BYTE); //puts the cursor at line 0 char 0
      break;
    case 3:
      lcd.print(212,BYTE); //puts the cursor at line 0 char 0
      break;
    default:
      selectLine(0); //defaults back to line 0
      break;
  }
}

void goTo(int position) { //position = line 1: 0-19, line 2: 20-39, etc, 79+ defaults back to 0
  if (position<20){ Serial.print(0xFE, BYTE);   //command flag
                Serial.print((position+128), BYTE);    //position
  }else if (position<40){Serial.print(0xFE, BYTE);   //command flag
                Serial.print((position+128+64-20), BYTE);    //position 
  }else if (position<60){Serial.print(0xFE, BYTE);   //command flag
                Serial.print((position+128+20-40), BYTE);    //position
  }else if (position<80){Serial.print(0xFE, BYTE);   //command flag
                Serial.print((position+128+84-60), BYTE);    //position              
  } else { goTo(0); }
}

void clearLCD(){
   Serial.print(0xFE, BYTE);   //command flag
   Serial.print(0x01, BYTE);   //clear command.
}

void backlightOn(){  //turns on the backlight
    Serial.print(0x7C, BYTE);   //command flag for backlight stuff
    Serial.print(157, BYTE);    //light level.
}

void backlightOff(){  //turns off the backlight
    Serial.print(0x7C, BYTE);   //command flag for backlight stuff
    Serial.print(128, BYTE);     //light level for off.
}

void backlight50(){  //sets the backlight at 50% brightness
    Serial.print(0x7C, BYTE);   //command flag for backlight stuff
    Serial.print(143, BYTE);     //light level for off.
}

void serCommand(){   //a general function to call the command flag for issuing all other commands   
  Serial.print(0xFE, BYTE);
}
</source>

See also


External links

Retrieved from "http://wiki.midsouthmakers.org/index.php?title=Serial_enabled_LCD_backpack&oldid=635"