examples/lcd-adafruit.c

/*
 * lcd-adafruit.c:
 *	Text-based LCD driver test code
 *	This is designed to drive the Adafruit RGB LCD Plate
 *	with the additional 5 buttons for the Raspberry Pi
 *
 * Copyright (c) 2012-2013 Gordon Henderson.
 ***********************************************************************
 * This file is part of wiringPi:
 *	https://projects.drogon.net/raspberry-pi/wiringpi/
 *
 *    wiringPi is free software: you can redistribute it and/or modify
 *    it under the terms of the GNU Lesser General Public License as published by
 *    the Free Software Foundation, either version 3 of the License, or
 *    (at your option) any later version.
 *
 *    wiringPi is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU Lesser General Public License for more details.
 *
 *    You should have received a copy of the GNU Lesser General Public License
 *    along with wiringPi.  If not, see <http://www.gnu.org/licenses/>.
 ***********************************************************************
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <time.h>

#include <wiringPi.h>
#include <mcp23017.h>
#include <lcd.h>

#ifndef	TRUE
#  define	TRUE	(1==1)
#  define	FALSE	(1==2)
#endif


// Defines for the Adafruit Pi LCD interface board

#define	AF_BASE		100
#define	AF_RED		(AF_BASE + 6)
#define	AF_GREEN	(AF_BASE + 7)
#define	AF_BLUE		(AF_BASE + 8)

#define	AF_E		(AF_BASE + 13)
#define	AF_RW		(AF_BASE + 14)
#define	AF_RS		(AF_BASE + 15)

#define	AF_DB4		(AF_BASE + 12)
#define	AF_DB5		(AF_BASE + 11)
#define	AF_DB6		(AF_BASE + 10)
#define	AF_DB7		(AF_BASE +  9)

#define	AF_SELECT	(AF_BASE +  0)
#define	AF_RIGHT	(AF_BASE +  1)
#define	AF_DOWN		(AF_BASE +  2)
#define	AF_UP		(AF_BASE +  3)
#define	AF_LEFT		(AF_BASE +  4)


// User-Defined character test

static unsigned char newChar [8] = 
{
  0b00100,
  0b00100,
  0b00000,
  0b00100,
  0b01110,
  0b11011,
  0b11011,
  0b10001,
} ;

// Global lcd handle:

static int lcdHandle ;

/*
 * usage:
 *********************************************************************************
 */

int usage (const char *progName)
{
  fprintf (stderr, "Usage: %s colour\n", progName) ;
  return EXIT_FAILURE ;
}


/*
 * scrollMessage:
 *********************************************************************************
 */

static const char *message =
  "                    "
  "Wiring Pi by Gordon Henderson. HTTP://WIRINGPI.COM/"
  "                    " ;

void scrollMessage (int line, int width)
{
  char buf [32] ;
  static int position = 0 ;
  static int timer = 0 ;

  if (millis () < timer)
    return ;

  timer = millis () + 200 ;

  strncpy (buf, &message [position], width) ;
  buf [width] = 0 ;
  lcdPosition (lcdHandle, 0, line) ;
  lcdPuts (lcdHandle, buf) ;

  if (++position == (strlen (message) - width))
    position = 0 ;
}


/*
 * setBacklightColour:
 *	The colour outputs are inverted.
 *********************************************************************************
 */

static void setBacklightColour (int colour)
{
  colour &= 7 ;

  digitalWrite (AF_RED,   !(colour & 1)) ;
  digitalWrite (AF_GREEN, !(colour & 2)) ;
  digitalWrite (AF_BLUE,  !(colour & 4)) ;
}


/*
 * adafruitLCDSetup:
 *	Setup the Adafruit board by making sure the additional pins are
 *	set to the correct modes, etc.
 *********************************************************************************
 */

static void adafruitLCDSetup (int colour)
{
  int i ;

//	Backlight LEDs

  pinMode (AF_RED,   OUTPUT) ;
  pinMode (AF_GREEN, OUTPUT) ;
  pinMode (AF_BLUE,  OUTPUT) ;
  setBacklightColour (colour) ;

//	Input buttons

  for (i = 0 ; i <= 4 ; ++i)
  {
    pinMode (AF_BASE + i, INPUT) ;
    pullUpDnControl (AF_BASE + i, PUD_UP) ;	// Enable pull-ups, switches close to 0v
  }

// Control signals

  pinMode (AF_RW, OUTPUT) ; digitalWrite (AF_RW, LOW) ;	// Not used with wiringPi - always in write mode

// The other control pins are initialised with lcdInit ()

  lcdHandle = lcdInit (2, 16, 4, AF_RS, AF_E, AF_DB4,AF_DB5,AF_DB6,AF_DB7, 0,0,0,0) ;

  if (lcdHandle < 0)
  {
    fprintf (stderr, "lcdInit failed\n") ;
    exit (EXIT_FAILURE) ;
  }
}


/*
 * waitForEnter:
 *	On the Adafruit display, wait for the select button
 *********************************************************************************
 */

static void waitForEnter (void)
{
  printf ("Press SELECT to continue: ") ; fflush (stdout) ;

  while (digitalRead (AF_SELECT) == HIGH)	// Wait for push
    delay (1) ;

  while (digitalRead (AF_SELECT) == LOW)	// Wait for release
    delay (1) ;

  printf ("OK\n") ;
}


/*
 * speedTest:
 *	Test the update speed of the display
 *********************************************************************************
 */

static void speedTest (void)
{
  unsigned int start, end, taken ;
  int times ;

  lcdClear (lcdHandle) ;
  start = millis () ;
  for (times = 0 ; times < 10 ; ++times)
  {
    lcdPuts (lcdHandle, "0123456789ABCDEF") ;
    lcdPuts (lcdHandle, "0123456789ABCDEF") ;
  }
  end   = millis () ;
  taken = (end - start) / 10;

  lcdClear (lcdHandle) ;
  lcdPosition (lcdHandle, 0, 0) ; lcdPrintf (lcdHandle, "Speed: %dmS", taken) ;
  lcdPosition (lcdHandle, 0, 1) ; lcdPrintf (lcdHandle, "For full update") ;

  waitForEnter () ;

  lcdClear (lcdHandle) ;
  lcdPosition (lcdHandle, 0, 0) ; lcdPrintf (lcdHandle, "Time: %dmS", taken / 32) ;
  lcdPosition (lcdHandle, 0, 1) ; lcdPrintf (lcdHandle, "Per character") ;

  waitForEnter () ;

  lcdClear (lcdHandle) ;
  lcdPosition (lcdHandle, 0, 0) ; lcdPrintf (lcdHandle, "%d cps...", 32000 / taken) ;

  waitForEnter () ;
}


/*
 * The works
 *********************************************************************************
 */

int main (int argc, char *argv[])
{
  int colour ;
  int cols = 16 ;
  int waitForRelease = FALSE ;

  struct tm *t ;
  time_t tim ;

  char buf [32] ;

  if (argc != 2)
    return usage (argv [0]) ;

  printf ("Raspberry Pi Adafruit LCD test\n") ;
  printf ("==============================\n") ;

  colour = atoi (argv [1]) ;

  wiringPiSetupSys () ;
  mcp23017Setup (AF_BASE, 0x20) ;

  adafruitLCDSetup (colour) ;

  lcdPosition (lcdHandle, 0, 0) ; lcdPuts (lcdHandle, "Gordon Henderson") ;
  lcdPosition (lcdHandle, 0, 1) ; lcdPuts (lcdHandle, "  wiringpi.com  ") ;

  waitForEnter () ;

  lcdPosition (lcdHandle, 0, 1) ; lcdPuts (lcdHandle, "Adafruit RGB LCD") ;

  waitForEnter () ;

  lcdCharDef  (lcdHandle, 2, newChar) ;

  lcdClear    (lcdHandle) ;
  lcdPosition (lcdHandle, 0, 0) ;
  lcdPuts     (lcdHandle, "User Char: ") ;
  lcdPutchar  (lcdHandle, 2) ;

  lcdCursor      (lcdHandle, TRUE) ;
  lcdCursorBlink (lcdHandle, TRUE) ;

  waitForEnter () ;

  lcdCursor      (lcdHandle, FALSE) ;
  lcdCursorBlink (lcdHandle, FALSE) ;

  speedTest () ;

  lcdClear (lcdHandle) ;

  for (;;)
  {
    scrollMessage (0, cols) ;
    
    tim = time (NULL) ;
    t = localtime (&tim) ;

    sprintf (buf, "%02d:%02d:%02d", t->tm_hour, t->tm_min, t->tm_sec) ;

    lcdPosition (lcdHandle, (cols - 8) / 2, 1) ;
    lcdPuts     (lcdHandle, buf) ;

// Check buttons to cycle colour

// If Up or Down are still pushed, then skip

    if (waitForRelease)
    {
      if ((digitalRead (AF_UP) == LOW) || (digitalRead (AF_DOWN) == LOW))
	continue ;
      else
	waitForRelease = FALSE ;
    }

    if (digitalRead (AF_UP) == LOW)	// Pushed
    {
      colour = colour + 1 ;
      if (colour == 8)
	colour = 0 ;
      setBacklightColour (colour) ;
      waitForRelease = TRUE ;
    }

    if (digitalRead (AF_DOWN) == LOW)	// Pushed
    {
      colour = colour - 1 ;
      if (colour == -1)
	colour = 7 ;
      setBacklightColour (colour) ;
      waitForRelease = TRUE ;
    }

  }

  return 0 ;
}