Serial LCD by Scott Edwards and Arduino
Zo stránky SensorWiki
This serial LCD is not a direct connectible to the Arduino boards as it uses inverted signals (which is OK if You use e.g. RS-232 or Basic Stamp).
Solutions:
a) use an hardware inverter. You can either use one section of an inverter IC, like a 7404, or a simple one-transistor inverter.
b) use an improved NewSoftSerial library. It enables to invert signals. Following program works like a charm.
#include <NewSoftSerial.h>
#define rxPin 2
#define txPin 3
#define INVERTED true // this is impossible with standard Software Serial library
NewSoftSerial lcd(rxPin, txPin,INVERTED); // set up a new serial port
void setup() {
pinMode(rxPin, INPUT); // define pin modes for tx, rx:
pinMode(txPin, OUTPUT);
lcd.begin(9600);
delay(100);
lcd.print(254,BYTE);
lcd.print(1,BYTE);
delay(10);
lcd.print(254,BYTE);
lcd.print(1,BYTE);
delay(10);
lcd.print(254,BYTE);
lcd.print(2 ,BYTE);
delay(10);
lcd.print("Hello, World!");
}
void loop() {
lcd.print(254,BYTE);
lcd.print(192,BYTE); // set the cursor to column 0, line 1
lcd.print(millis()/1000); // print the number of seconds since reset:
}