Library and example sketch

1 files changed, 260 insertions, 0 deletions

diff --git a/OLEDFourBit/OLEDFourBit.cpp b/OLEDFourBit/OLEDFourBit.cpp
new file mode 100644
index 0000000..004ba15
--- /dev/null
+++ b/OLEDFourBit/OLEDFourBit.cpp
@@ -0,0 +1,260 @@
+#include "OLEDFourBit.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <inttypes.h>
+#include "Arduino.h"
+
+OLEDFourBit::OLEDFourBit(uint8_t rs, uint8_t rw, uint8_t enable, uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7)
+{
+  init(rs, rw, enable, d4, d5, d6, d7);
+}
+
+void OLEDFourBit::init(uint8_t rs, uint8_t rw, uint8_t enable, uint8_t d4, uint8_t d5, uint8_t d6, uint8_t d7)
+{
+  _rs_pin = rs;
+  _rw_pin = rw;
+  _enable_pin = enable;
+  _busy_pin = d7;
+
+  _data_pins[0] = d4;
+  _data_pins[1] = d5;
+  _data_pins[2] = d6;
+  _data_pins[3] = d7;
+
+
+  pinMode(_rs_pin, OUTPUT);
+  pinMode(_rw_pin, OUTPUT);
+  pinMode(_enable_pin, OUTPUT);
+
+  _displayfunction = LCD_FUNCTIONSET | LCD_4BITMODE;
+
+  begin(20, 4);
+}
+
+void OLEDFourBit::begin(uint8_t cols, uint8_t lines) {
+  _numlines = lines;
+  _currline = 0;
+
+  pinMode(_rs_pin, OUTPUT);
+  pinMode(_rw_pin, OUTPUT);
+  pinMode(_enable_pin, OUTPUT);
+
+  digitalWrite(_rs_pin, LOW);
+  digitalWrite(_enable_pin, LOW);
+  digitalWrite(_rw_pin, LOW);
+
+  // SEE PAGE 20 of NHD-0420DZW-AY5
+  delayMicroseconds(50000); // wait 50 ms just to be sure tha the lcd is initialized
+
+  // Now we pull both RS and R/W low to begin commands
+
+  for (int i = 0; i < 4; i++) {
+    pinMode(_data_pins[i], OUTPUT);
+    digitalWrite(_data_pins[i], LOW);
+  }
+
+  delayMicroseconds(100000);
+  write4bits(0x03);
+  delayMicroseconds(100000);
+  write4bits(0x02);
+  delayMicroseconds(10000);
+  write4bits(0x02);
+  delayMicroseconds(10000);
+  write4bits(0x08);
+
+
+  //command(0x28);
+  delayMicroseconds(10000);
+
+  command(0x08);	// Display off
+  delayMicroseconds(10000);
+
+  command(0x01);	// display clear
+  delayMicroseconds(10000);
+
+  command(0x06);	// Entry Mode Set:
+  delayMicroseconds(10000);
+
+
+  command(0x02);	// Home
+  delayMicroseconds(10000);
+
+  command(0x0C);	// display on/ cursor on/ cursor blink
+  delayMicroseconds(10000);
+
+
+}
+
+/********** high level commands, for the user! */
+void OLEDFourBit::clear()
+{
+  command(LCD_CLEARDISPLAY);  // clear display, set cursor position to zero
+}
+
+void OLEDFourBit::home()
+{
+  command(LCD_RETURNHOME);  // set cursor position to zero
+}
+
+void OLEDFourBit::setCursor(uint8_t col, uint8_t row)
+{
+  uint8_t row_offsets[] = { 0x00, 0x40, 0x14, 0x54 };
+  if ( row >= _numlines ) {
+    row = 0;  //write to first line if out off bounds
+  }
+
+  command(LCD_SETDDRAMADDR | (col + row_offsets[row]));
+}
+
+// Turn the display on/off (quickly)
+void OLEDFourBit::noDisplay() {
+  _displaycontrol &= ~LCD_DISPLAYON;
+  command(LCD_DISPLAYCONTROL | _displaycontrol);
+}
+void OLEDFourBit::display() {
+  _displaycontrol |= LCD_DISPLAYON;
+  command(LCD_DISPLAYCONTROL | _displaycontrol);
+}
+
+// Turns the underline cursor on/off
+void OLEDFourBit::noCursor() {
+  _displaycontrol &= ~LCD_CURSORON;
+  command(LCD_DISPLAYCONTROL | _displaycontrol);
+}
+void OLEDFourBit::cursor() {
+  _displaycontrol |= LCD_CURSORON;
+  command(LCD_DISPLAYCONTROL | _displaycontrol);
+}
+
+// Turn on and off the blinking cursor
+void OLEDFourBit::noBlink() {
+  _displaycontrol &= ~LCD_BLINKON;
+  command(LCD_DISPLAYCONTROL | _displaycontrol);
+}
+void OLEDFourBit::blink() {
+  _displaycontrol |= LCD_BLINKON;
+  command(LCD_DISPLAYCONTROL | _displaycontrol);
+}
+
+// These commands scroll the display without changing the RAM
+void OLEDFourBit::scrollDisplayLeft(void) {
+  command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVELEFT);
+}
+void OLEDFourBit::scrollDisplayRight(void) {
+  command(LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT);
+}
+
+// This is for text that flows Left to Right
+void OLEDFourBit::leftToRight(void) {
+  _displaymode |= LCD_ENTRYLEFT;
+  command(LCD_ENTRYMODESET | _displaymode);
+}
+
+// This is for text that flows Right to Left
+void OLEDFourBit::rightToLeft(void) {
+  _displaymode &= ~LCD_ENTRYLEFT;
+  command(LCD_ENTRYMODESET | _displaymode);
+}
+
+// This will 'right justify' text from the cursor
+void OLEDFourBit::autoscroll(void) {
+  _displaymode |= LCD_ENTRYSHIFTINCREMENT;
+  command(LCD_ENTRYMODESET | _displaymode);
+}
+
+// This will 'left justify' text from the cursor
+void OLEDFourBit::noAutoscroll(void) {
+  _displaymode &= ~LCD_ENTRYSHIFTINCREMENT;
+  command(LCD_ENTRYMODESET | _displaymode);
+}
+
+// Allows us to fill the first 8 CGRAM locations
+// with custom characters
+void OLEDFourBit::createChar(uint8_t location, uint8_t charmap[]) {
+  location &= 0x7; // we only have 8 locations 0-7
+  command(LCD_SETCGRAMADDR | (location << 3));
+  for (int i=0; i<8; i++) {
+    write(charmap[i]);
+  }
+}
+
+/*********** mid level commands, for sending data/cmds */
+
+inline void OLEDFourBit::command(uint8_t value) {
+  send(value, LOW);
+  waitBusy();
+}
+
+inline size_t OLEDFourBit::write(uint8_t value) {
+  send(value, HIGH);
+  waitBusy();
+}
+
+/************ low level data pushing commands **********/
+
+// write either command or data
+void OLEDFourBit::send(uint8_t value, uint8_t mode) {
+  digitalWrite(_rs_pin, mode);
+  pinMode(_rw_pin, OUTPUT);
+  digitalWrite(_rw_pin, LOW);
+
+  write4bits(value>>4);
+  write4bits(value);
+}
+
+void OLEDFourBit::pulseEnable(void) {
+  digitalWrite(_enable_pin, HIGH);
+  delayMicroseconds(100);    // enable pulse must be >450ns
+  digitalWrite(_enable_pin, LOW);
+}
+
+void OLEDFourBit::write4bits(uint8_t value) {
+  for (int i = 0; i < 4; i++) {
+    pinMode(_data_pins[i], OUTPUT);
+    digitalWrite(_data_pins[i], (value >> i) & 0x01);
+  }
+  delayMicroseconds(100);
+  pulseEnable();
+}
+
+void OLEDFourBit::waitBusy(void) {
+  //delayMicroseconds(5000);
+  unsigned char busy = 1;
+  pinMode(_busy_pin, INPUT);
+  digitalWrite(_rs_pin, LOW);
+  digitalWrite(_rw_pin, HIGH);
+  do{
+  	digitalWrite(_enable_pin, LOW);
+  	digitalWrite(_enable_pin, HIGH);
+  	delayMicroseconds(10);
+  	busy = digitalRead(_busy_pin);
+  	digitalWrite(_enable_pin, LOW);
+
+  	pulseEnable();		// get remaining 4 bits, which are not used.
+
+  }while(busy);
+
+  pinMode(_busy_pin, OUTPUT);
+  digitalWrite(_rw_pin, LOW);
+}
+
+char OLEDFourBit::readChar(void){
+  char value=0x00;
+  for (int i = 0; i < 4; i++) {
+    pinMode(_data_pins[i], INPUT);
+  }
+  digitalWrite(_rs_pin, HIGH);
+  digitalWrite(_rw_pin, HIGH);
+  pulseEnable();
+  delayMicroseconds(600);
+  for (int i = 0; i < 4; i++) {
+    value = value | (digitalRead(_data_pins[i]) << (i+4));
+  }
+  pulseEnable();
+  delayMicroseconds(600);
+  for (int i = 0; i < 4; i++) {
+    value = value | (digitalRead(_data_pins[i]) << (i));
+  }
+  return value;
+}
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