display.h

00001 /* University of York Robotics Laboratory PsiSwarm Library: Display Driver Header File
00002  *
00003  * Copyright 2016 University of York
00004  *
00005  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
00007  * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS
00008  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00009  * See the License for the specific language governing permissions and limitations under the License.
00010  *
00011  * File: display.h
00012  *
00013  * (C) Dept. Electronics & Computer Science, University of York
00014  * James Hilder, Alan Millard, Alexander Horsfield, Homero Elizondo, Jon Timmis
00015  *
00016  * PsiSwarm Library Version: 0.8
00017  *
00018  * October 2016
00019  *
00020  *
00021  * Driver for the Midas 16x2 I2C LCD Display (MCCOG21605x6W) LCD
00022  *
00023  * Farnell part 2218942 or 2063206
00024  *
00025  */
00026 
00027 
00028 #ifndef DISPLAY_H
00029 #define DISPLAY_H
00030 
00031 #define PAGE_TIME 0.4
00032 #define CLEAR_TIME 0.8
00033 
00034 /**
00035  * Display class
00036  * Functions for use with the Midas 16x2 I2C LCD Display (MCCOG21605x6W) LCD
00037  * Farnell part 2218942 or 2063206
00038  *
00039  * Example:
00040  * @code
00041  * #include "psiswarm.h"
00042  *
00043  * int main() {
00044  *     init();
00045  *     display.clear_display;       //Clears display
00046  *     display.set_position(0,2);   //Set cursor to row 0 column 2
00047  *     display.write_string("YORK ROBOTICS");
00048  *     display.set_position(1,3);   //Set cursor to row 1 column 3
00049  *     display.write_string("LABORATORY");
00050  * }
00051  * @endcode
00052 */
00053 class Display : public Stream
00054 {
00055 
00056 // Public Functions
00057 
00058 public:
00059 
00060     /** Create the LCD Display object connected to the default pins
00061      * (sda = p28, scl = p27, reset = p29, backlight = p30)
00062      */
00063     Display();
00064 
00065     /** Create the LCD Display object connected to specific pins
00066      *
00067      * @param sda pin   - default is p28
00068      * @param scl pin   - default is p27
00069      * @param reset pin - default is p29
00070      * @param backlight pin - default is p30
00071      */
00072     Display(PinName sda, PinName scl, PinName reset, PinName backlight);
00073 
00074     /** Clear the display
00075     */
00076     void clear_display(void);
00077 
00078     /** Set cursor to home position
00079     */
00080     void home(void);
00081 
00082     /** Print string message
00083     * @param message - The null-terminated message to print
00084     */
00085     void write_string(char * message);
00086 
00087     /** Print string message of given length
00088     * @param message - The message to print
00089     * @param length - The number of characters to display
00090     */
00091     void write_string(char * message, char length);
00092 
00093     /** Set the row and column of cursor position
00094     * @param row - The row of the display to set the cursor to (either 0 or 1)
00095     * @param column - The column of the display to set the cursor to (range 0 to 15)
00096     */
00097     void set_position(char row, char column);
00098 
00099     /** Enable or disable cursor
00100     * @param enable - Set to 1 to enable the cursor visibility
00101     */
00102     void set_cursor(char enable);
00103 
00104     /** Enable or disable cursor blink
00105     * @param enable - Set to 1 to enable the cursor blinking mode
00106     */
00107     void set_blink(char enable);
00108 
00109     /** Enable or disable display
00110     * @param enable - Set to 1 to enable the display output
00111     */
00112     void set_display(char enable);
00113 
00114     /** Set the brightness of the backlight
00115     * @param brightness - Sets the brightness of the display (range 0.0 to 1.0)
00116     */
00117     void set_backlight_brightness(float brightness);
00118 
00119     // Special function for when debug messages are sent to display
00120     void debug_page(char * message, char length);
00121 
00122     // Internal function used to restore display after debug messages
00123     void IF_restore_page(void);
00124 
00125     // Internal function used to show multi-page debug messages
00126     void IF_debug_multipage(void);
00127 
00128     // Internal function used to toggle backlight
00129     void IF_backlight_toggle(void);
00130 
00131     //Parts of initialisation routine
00132     void post_init(void);
00133     void post_post_init(void);
00134 
00135     // Send a 1-byte control message to the display
00136     int i2c_message(char byte);
00137 
00138     // Default initialisation sequence for the display
00139     void init_display(char mode);
00140 
00141     int disp_putc(int c);
00142 
00143 
00144 private :
00145 
00146     I2C _i2c;
00147     DigitalOut _reset;
00148     DigitalOut _backlight;
00149 
00150     char display_on;
00151     char cursor_on;
00152     char blink_on;
00153 
00154     void _set_display();
00155 
00156     virtual int _putc(int c);
00157     virtual int _getc();
00158 
00159 };
00160 
00161 #endif // DISPLAY_H