display.cpp

00001 /* University of York Robotics Laboratory PsiSwarm Library: Display Driver Source File
00002  * 
00003  * File: display.cpp
00004  *
00005  * (C) Dr James Hilder, Dept. Electronics & Computer Science, University of York
00006  * 
00007  * PsiSwarm Library Version: 0.3
00008  * Display Driver Version:   0.2
00009  *
00010  * October 2015
00011  *
00012  * Driver for the Midas 16x2 I2C LCD Display (MCCOG21605x6W) LCD
00013  * [Farnell part 2218942 or 2063206]
00014  *
00015  */ 
00016  
00017 #include "psiswarm.h"
00018 
00019 Timeout init_timeout;
00020 Timeout backlight_timeout;
00021 Timeout debug_timeout;
00022 int backlight_on_time;
00023 int backlight_off_time;
00024 char backlight_step;
00025 char multipage[200];
00026 char multipage_length = 0;
00027 char preserve_line_1 [17];
00028 char preserve_line_2 [17];
00029 char c_row=0;
00030 char c_column=0;
00031 char p_row;
00032 char p_column;
00033 
00034 
00035 Display::Display(PinName sda, PinName scl, PinName reset, PinName backlight) :  Stream("display"), _i2c(sda,scl), _reset(reset), _backlight(backlight)  {
00036 }
00037 
00038 Display::Display() :  Stream("display"), _i2c(p28,p27), _reset(p29), _backlight(p30)  {
00039 }
00040 
00041 int Display::i2c_message(char byte){
00042    char bytes [2];
00043    bytes[0]=0x80;
00044    bytes[1]=byte;
00045    int ret=_i2c.write(LCD_ADDRESS,bytes,2);  
00046    wait(0.01);
00047    return ret;
00048 }
00049 
00050 int Display::disp_putc(int c){
00051    char message [2];
00052    message[0]=0x40;
00053    message[1]=c;
00054    _i2c.write(LCD_ADDRESS,message,2);
00055    wait(0.01);
00056    return c;
00057 }
00058 
00059 void Display::init_display(char mode){
00060    //Set initial states: display on, cursor off
00061    display_on = 1;
00062    set_backlight_brightness(1);
00063    cursor_on = 0;
00064    blink_on  = 0;
00065     
00066    _reset=1;
00067    wait(0.02);
00068    //Set reset low
00069    _reset=0;
00070    wait(0.001);
00071    _reset=1;
00072    wait(0.03);
00073    i2c_message(0x38); 
00074    i2c_message(0x39); 
00075    i2c_message(0x14); 
00076    i2c_message(0x74); 
00077    i2c_message(0x54); 
00078    i2c_message(0x6F); 
00079    _set_display();
00080    clear_display(); 
00081    char psis[17];
00082    for(int i=0;i<16;i++){
00083        psis[i]=0x1D;
00084    }
00085    set_position(0,0);
00086    write_string(psis,16);
00087    set_position(1,0);
00088    write_string(psis,16);
00089    wait(0.25);
00090    clear_display();
00091    if(mode == 0){
00092    set_position(0,0);
00093    write_string("  YORK ROBOTICS");
00094    set_position(1,0);
00095    write_string("   LABORATORY");
00096    init_timeout.attach(this,&Display::post_init,0.3);}
00097    else {      
00098    set_position(0,0);
00099    write_string("Hold button to");
00100    set_position(1,0);
00101    write_string("launch demo code");
00102     }
00103 } 
00104 
00105 void Display::post_init(){
00106     clear_display();
00107     home();
00108     write_string("PSI SWARM ROBOT");
00109     set_position(1,0);
00110     char line [17];
00111     sprintf(line,"VERSION %1.2f", SOFTWARE_VERSION_CODE  );
00112     set_position(1,0);
00113     write_string(line);
00114     init_timeout.attach(this,&Display::post_post_init,0.3);
00115 }
00116 
00117 void Display::post_post_init(){
00118     clear_display();
00119     home();
00120 }
00121 
00122 void Display::write_string(char * message){
00123    size_t length = strlen(message);
00124    if (length > 16) length = 16;
00125    char to_send [length+1];
00126    to_send[0]=0x40;
00127    for(int i=0;i<length;i++){
00128      to_send[i+1] = message[i];
00129    }
00130    _i2c.write(LCD_ADDRESS,to_send,length+1);
00131    // Add to saved buffer
00132    int count = 0;
00133    for(int i=c_column;i<16;i++){
00134        if(count < length){
00135             if(c_row == 0) preserve_line_1[i] = message[count];
00136             else preserve_line_2[i] = message[count];  
00137        }
00138        count++;
00139    }
00140    c_column+=length;
00141    if(c_column>15) c_column=15;
00142 }
00143 
00144 
00145 void Display::write_string(char * message, char length){
00146    char to_send [length+1];
00147    to_send[0]=0x40;
00148    for(int i=0;i<length;i++){
00149      to_send[i+1] = message[i];
00150    }
00151    _i2c.write(LCD_ADDRESS,to_send,length+1);
00152    // Add to saved buffer
00153    int count = 0;
00154    for(int i=c_column;i<16;i++){
00155        if(count < length){
00156             if(c_row == 0) preserve_line_1[i] = message[count];
00157             else preserve_line_2[i] = message[count];  
00158        }
00159        count++;
00160    }
00161    c_column+=length;
00162    if(c_column>15) c_column=15;
00163 }
00164 
00165 void Display::set_position(char row, char column){
00166   if(row < 2 && column < 16){
00167     char pos = 128 +((row * 64)+column);
00168     i2c_message(pos);
00169     c_row= row;
00170     c_column = column;
00171   }
00172 }
00173 
00174 void Display::set_cursor(char enable){
00175   cursor_on=enable;
00176   _set_display();
00177 }
00178 
00179 void Display::set_blink(char enable){
00180   blink_on=enable;
00181     _set_display();
00182 }
00183 
00184 void Display::set_display(char enable){
00185   display_on=enable;
00186     _set_display();
00187 }
00188 
00189 void Display::set_backlight_brightness(float brightness){
00190     if(brightness > 1) brightness = 0;
00191     if(brightness < 0) brightness = 0;
00192     backlight_brightness = brightness;
00193     if(backlight_brightness == 1) {
00194         backlight_timeout.detach();   
00195         _backlight = 1;
00196     }else{
00197         if(backlight_brightness == 0){
00198             backlight_timeout.detach();
00199             _backlight = 0;   
00200         }   else {
00201             backlight_on_time = (int) (10000.0f * backlight_brightness);
00202             backlight_off_time = 10000 - backlight_on_time;
00203             backlight_step = 0;
00204             _backlight = 0;
00205             backlight_timeout.attach_us(this,&Display::IF_backlight_toggle,backlight_off_time);
00206         }
00207     }
00208 }
00209 
00210 void Display::IF_backlight_toggle(){
00211     if(backlight_step == 0){
00212         _backlight = 1;
00213         backlight_step = 1;
00214         backlight_timeout.attach_us(this,&Display::IF_backlight_toggle,backlight_on_time);
00215     }   else {
00216         _backlight = 0;
00217         backlight_step = 0;
00218         backlight_timeout.attach_us(this,&Display::IF_backlight_toggle,backlight_off_time);
00219     }
00220 }
00221 void Display::clear_display(){
00222   for(int i=0;i<16;i++){
00223       preserve_line_1[i] = 0x20;
00224       preserve_line_2[i] = 0x20;
00225   }
00226   i2c_message(0x01);
00227 }
00228 
00229 void Display::home(){
00230   c_row = 0;
00231   c_column = 0;
00232   i2c_message(0x02);
00233 }
00234 
00235 void Display::debug_page(char * message, char length){
00236     p_row=c_row;
00237     p_column=c_column;
00238     i2c_message(0x01);
00239     home();
00240     char multipage_mode = 0;
00241     char line_1[18];
00242     char line_2[18];
00243     line_1[0]=0x40;
00244     line_2[0]=0x40;
00245     if(length > 16){
00246         strncpy(line_1+1, message, 16);
00247         char f_length = length - 16;
00248         if(f_length > 16) {
00249             f_length = 16;
00250             multipage_mode = 1;
00251         }
00252         strncpy(line_2+1, message+16, f_length);
00253         line_1[17]=0;
00254         line_2[f_length+1]=0;
00255         _i2c.write(LCD_ADDRESS,line_1,17);
00256         set_position(1,0);
00257         _i2c.write(LCD_ADDRESS,line_2,f_length+1);
00258     } else {
00259         strncpy(line_1+1, message, length);
00260         _i2c.write(LCD_ADDRESS,line_1,length+1);
00261         }
00262     if(multipage_mode == 1){
00263         strncpy(multipage, message + 32, length - 32);
00264         multipage_length = length - 32;
00265         debug_timeout.attach(this,&Display::IF_debug_multipage,PAGE_TIME);
00266     } else debug_timeout.attach(this,&Display::IF_restore_page,CLEAR_TIME);
00267 }
00268 
00269 void Display::IF_restore_page(){
00270     i2c_message(0x01);
00271     home();
00272     char line_1[17];
00273     char line_2[17];
00274     line_1[0]=0x40;
00275     line_2[0]=0x40;
00276     strncpy(line_1+1, preserve_line_1, 16);
00277     strncpy(line_2+1, preserve_line_2, 16);
00278     _i2c.write(LCD_ADDRESS,line_1,17);
00279     set_position(1,0);
00280     _i2c.write(LCD_ADDRESS,line_2,17);
00281     set_position(p_row,p_column);
00282 }
00283 
00284 void Display::IF_debug_multipage(){
00285     i2c_message(0x01);
00286     home();
00287     char multipage_mode = 0;
00288     char line_1[18];
00289     char line_2[18];
00290     line_1[0]=0x40;
00291     line_2[0]=0x40;
00292     if(multipage_length > 16){
00293         strncpy(line_1+1, multipage, 16);
00294         char f_length = multipage_length - 16;
00295         if(f_length > 16) {
00296             f_length = 16;
00297             multipage_mode = 1;
00298         }
00299         strncpy(line_2+1, multipage+16, f_length);
00300         line_1[17]=0;
00301         line_2[f_length+1]=0;
00302        _i2c.write(LCD_ADDRESS,line_1,17);
00303         set_position(1,0);
00304         _i2c.write(LCD_ADDRESS,line_2,f_length+1);
00305     } else  {
00306         strncpy(line_1+1, multipage, multipage_length);
00307         _i2c.write(LCD_ADDRESS,line_1,multipage_length+1);
00308         }
00309     if(multipage_mode == 1){
00310         char temp[200];
00311         strncpy(temp, multipage + 32, multipage_length - 32);
00312         multipage_length -= 32;
00313         strncpy(multipage, temp, multipage_length);
00314         debug_timeout.attach(this,&Display::IF_debug_multipage,PAGE_TIME);
00315     }else debug_timeout.attach(this,&Display::IF_restore_page,CLEAR_TIME);
00316 }
00317 
00318 void Display::_set_display(){
00319     char mode = 8;
00320     if(display_on>0) mode += 4;
00321     if(cursor_on>0) mode += 2;
00322     if(blink_on>0) mode ++;
00323     i2c_message(mode);
00324 }
00325 
00326 
00327 int Display::_putc (int c) {
00328     putc(c);
00329     return(c);
00330 }
00331 
00332 int Display::_getc (void) {
00333     char r = 0;
00334     return(r);
00335 }