display.c

/*
 * IM-Me display functions
 *
 * Copyright 2010 Dave
 * http://daveshacks.blogspot.com/2010/01/im-me-lcd-interface-hacked.html
 *
 * Copyright 2010 Michael Ossmann
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#include <cc1110.h>
#include <stdint.h>
#include <stdio.h>

#include "5x7.h"
#include "bits.h"
#include "clock.h"
#include "display.h"
#include "ioCCxx10_bitdef.h"
#include "types.h"

void setIOPorts() {
  //No need to set PERCFG or P2DIR as default values on reset are fine
  P0SEL |= (BIT5 | BIT3 ); // set SCK and MOSI as peripheral outputs
  P0DIR |= BIT4 | BIT2; // set SSN and A0 as outputs
  P1DIR |= BIT1; // set LCDRst as output
  P2DIR = BIT3 | BIT4; // set LEDs  as outputs
  //LED_GREEN = LOW; // Turn the Green LED on (LEDs driven by reverse logic: 0 is ON)
}

// Set a clock rate of approx. 2.5 Mbps for 26 MHz Xtal clock
#define SPI_BAUD_M  170
#define SPI_BAUD_E  16

void configureSPI() {
  U0CSR = 0;  //Set SPI Master operation
  U0BAUD =  SPI_BAUD_M; // set Mantissa
  U0GCR = U0GCR_ORDER | SPI_BAUD_E; // set clock on 1st edge, -ve clock polarity, MSB first, and exponent
}
void tx(unsigned char ch) {
  U0DBUF = ch;
  while(!(U0CSR & U0CSR_TX_BYTE)); // wait for byte to be transmitted
  U0CSR &= ~U0CSR_TX_BYTE;         // Clear transmit byte status
}

void txData(unsigned char ch) {
  A0 = HIGH;
  tx(ch);
}

void txCtl(unsigned char ch){
  A0 = LOW;
  tx(ch);
}

void LCDReset(void) {
  LCDRst = LOW; // hold down the RESET line to reset the display
  clock_delayms(1);
  LCDRst = HIGH;
  SSN = LOW;
  // send the initialisation commands to the LCD display
  txCtl(0xe2); // RESET cmd
  txCtl(0x24); // set internal resistor ratio
  txCtl(0x81); // set Vol Control
  txCtl(0x60); // set Vol Control - ctd
  txCtl(0xe6); // ?? -- don't know what this command is
  txCtl(0x00); // ?? -- don't know what this command is
  txCtl(0x2f); // set internal PSU operating mode
  txCtl(0xa1); // LCD bias set
  txCtl(0xaf); // Display ON
  txCtl(0xa4); // Normal (not all pixels) mode
  SSN = HIGH;
}

void LCDPowerSave() { // not tested yet; taken from spi trace
  txCtl(0xac); // static indicator off cmd
  txCtl(0xae); // LCD off
  txCtl(0xa5); // Display all Points on cmd = Power Save when following LCD off
}

void setCursor(unsigned char row, unsigned char col) {
  txCtl(0xb0 + row); // set cursor row
  txCtl(0x00 + (col & 0x0f)); // set cursor col low
  txCtl(0x10 + ( (col>>4) & 0x0f)); // set cursor col high
}

void setDisplayStart(unsigned char start) {
  txCtl(0x40 | (start & 0x3f)); // set Display start address
}

void setNormalReverse(unsigned char normal) {  // 0 = Normal, 1 = Reverse
  txCtl(0xa6 | (normal & 0x01) );
}

/* clear all LCD pixels */
void clear() {
  u8 row;
  u8 col;

  SSN = LOW;
  setDisplayStart(0);

  /* normal display mode (not inverted) */
  setNormalReverse(0);

  for (row = 0; row <= 9; row++) {
    setCursor(row, 0);
    for (col = 0; col < WIDTH; col++)
      txData(0x00);
  }

  SSN = HIGH;
}

/* sdcc provides printf if we provide this */
void putchar(char c) {
  uint8_t i;

  c &= 0x7f;

  if (c >= FONT_OFFSET) {
    for (i = 0; i < FONT_WIDTH; i++)
      txData(font[c - FONT_OFFSET][i]);
    /*    txData(0x00);*/
  }
}

void putchar_mask(char c, uint8_t mask) {
  uint8_t i;

  c &= 0x7f;

  if (c >= FONT_OFFSET) {
    for (i = 0; i < FONT_WIDTH; i++)
      txData(font[c - FONT_OFFSET][i] | mask);
    /*    txData(0x00);*/
  }  
}

/* Convenience function for debugging. */
void display_print_message(const char* msg, int row, int col) {
  setDisplayStart(0);
  SSN = LOW;
  setCursor(row, col);
  printf(msg);
  SSN = HIGH;
}