Arduino 驱动 2004 LCD

#include <LiquidCrystal.h>
// my pinout from L (LCD pin) to A (Arduino pin):
// LCD pin 1: Vss --> to Arduino GND
// LCD pin 2: Vdd --> to Arduino +5V
// LCD pin 3: V0 (contrast) --> to GND (I chose the PWM pin 10, see below)
// LCD pin 4: RS (register select) --> to Arduino pin 11
// LCD pin 5: R/W- (read/write) --> to Arduino pin 2
// LCD pin 6: E (H/L enable) --> to Arduino pin 3
// LCD pin 7: DB0 (data bit 0) --> to Arduino PIN 4
// LCD pin 8: DB1 (data bit 1) --> to Arduino PIN 5
// LCD pin 9: DB2 --> to Arduino PIN 6
// LCD pin 10: DB3 --> to Arduino PIN 7
// LCD pin 11: DB4 --> to Arduino PIN 14
// LCD pin 12: DB5 --> to Arduino PIN 15
// LCD pin 13: DB6 --> to Arduino PIN 16
// LCD pin 14: DB7 --> to Arduino PIN 17
// LCD pin 15: A/Vee (backlight+) --> to a 4.2Vcc source (see documentation)
// LCD pin 16: K (backlight-) --> to Arduino GND
LiquidCrystal lcd(11,2,3, 4,5,6,7, 14,15,16,17);
int contrast = 10;                 // PWM pin (contrast level)
int led = 13;                      // LED pin (alive led)
char *boot = "(C) AlfonSoftWare   Winstar 2004A KS0066"
"InterNational 2009  Arduino Diecimila   ";
void setup()                       // initialization
{
Serial.begin(115200);
pinMode(contrast, OUTPUT);
pinMode(led, OUTPUT);
analogWrite(contrast, 0);       // 0: maximum contrast  255: minimum
digitalWrite(led, 1);
lcd.clear();
lcd.print(boot);
}
void loop()                        // main loop
{
static int i=0, ctr=3;           // led blinking section
i = (i+1)&31;
digitalWrite(led, i>ctr);
if(!Serial.available())          // no incoming text?
{
delay(15);
return;
}
static char pos[80] =
{
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59,
20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39,
60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79,
};
static int con[9] = { 0, 30, 60, 90, 120, 150, 180, 210 };
char buf[81], *ptr = buf, chr, flg = 0;
int cur = 0;
memset(buf, ' ', sizeof(buf));
buf[80] = '\0';
delay(15);                     // wait for all chars to be in (80 chars at 57600)
while(Serial.available() > 0)  // for every character available:
{
chr = Serial.read();         // fetch next
if(chr == '\n')              // simulate carriage returns
{
  if(! flg)                  // ignore fake carriage returns
  {
    if(cur&lt;20) cur=20;       // from 1st to 2nd line
    else if(cur&lt;40) cur=40;  // from 2nd to 3rd line
    else if(cur&lt;60) cur=60;  // from 3rd to 4th line
  }
}
flg = 0;

if(chr &gt;= 1 &amp;&amp; chr &lt;= 9)     // contrast setting characters
{
  ctr = chr*3;
  analogWrite(contrast, con[chr-1]);
}

if(chr&lt;' ' || cur&gt;79)        // skip non-printable chars
  continue;                  // and out-of-area chars

buf[pos[cur++]] = chr;       // store character
if(!(cur % 20)) flg = 1;     // remember "end of line" condition

}
lcd.clear();
lcd.print(buf);                // output the formatted screenshot
Serial.print(buf);             // serial debug output
Serial.print("\r\n\n");
}