Wednesday, December 28, 2011

Arduino "Hello World" for BPI-216 Serial LCDs

Version 1.0 of the Arduino software includes an update to the SoftwareSerial library, which (among other things) can output inverted-TTL serial that works with our BPI-, BPK-, and BPP- series devices. The example sketch is after the break.

Hookup

In the pic at right (click to enlarge), a BPI-216L is connected to an Arduino Uno via a BSW-CBL wiring harness (a worthwhile option when you're buying the display). Connections are
  • Red: Arduino 5V to BPI +5
  • Black: Arduino GND to BPI GND
  • White: Arduino 3 to BPI SER
 If you want to use a different Arduino pin for serial output, you can change the 3 in #define txPin 3 to the desired pin number.




/*This program uses the updated SoftwareSerial distributed in v1.0 of 
the Arduino software. Users of earlier versions must download 
NewSoftSerial. */

#include <SoftwareSerial.h>

#define rxPin 255       // Not used, so set to invalid pin #
#define txPin 3         // Connect BPI/BPK's SER input to this pin.
#define inverted 1     // In setup, 1=inverted, 0=noninverted

const char clearScreen[ ] = {
  254,1,254,128,0};
const char message[ ] = "Hello World!" ;

/* 
Set up a new serial output using the pin definitions above. Note the 
argument "inverted," which instructs SoftwareSerial to output BPI/BPK-
compatible inverted-TTL serial (like RS-232, but without the +/- 
voltage swing).*/

SoftwareSerial mySerial =  SoftwareSerial(rxPin, txPin, inverted);

void setup()  {
  // define pin mode for tx:
  digitalWrite(txPin, LOW);   // Stop bit state for inverted serial
  pinMode(txPin, OUTPUT);
  mySerial.begin(9600);    // Set the data rate
  delay(10);              // wait (may not be needed w/ Arduino v1.0)
  mySerial.print(clearScreen);
  mySerial.print(message);  
}

void loop() {
  // ...
}

Arduino-compatible serial OLED: $39 at seetron.

1 comment:

  1. Hey thanks a bunch for this tip! Got an old SEE display going with my Arduino and I can still use the display with my BS-2 when necessary! Thanks again.

    Al

    ReplyDelete