display.cpp

00001 //=====[Libraries]=============================================================
00002 
00003 #include "mbed.h"
00004 #include "arm_book_lib.h"
00005 #include "display.h"
00006 
00007 //=====[Declaration of private defines]========================================
00008 
00009 #define DISPLAY_IR_CLEAR_DISPLAY   0b00000001
00010 #define DISPLAY_IR_ENTRY_MODE_SET  0b00000100
00011 #define DISPLAY_IR_DISPLAY_CONTROL 0b00001000
00012 #define DISPLAY_IR_FUNCTION_SET    0b00100000
00013 #define DISPLAY_IR_SET_DDRAM_ADDR  0b10000000
00014 
00015 #define DISPLAY_IR_ENTRY_MODE_SET_INCREMENT 0b00000010
00016 #define DISPLAY_IR_ENTRY_MODE_SET_DECREMENT 0b00000000
00017 #define DISPLAY_IR_ENTRY_MODE_SET_SHIFT     0b00000001
00018 #define DISPLAY_IR_ENTRY_MODE_SET_NO_SHIFT  0b00000000
00019 
00020 #define DISPLAY_IR_DISPLAY_CONTROL_DISPLAY_ON  0b00000100
00021 #define DISPLAY_IR_DISPLAY_CONTROL_DISPLAY_OFF 0b00000000
00022 #define DISPLAY_IR_DISPLAY_CONTROL_CURSOR_ON   0b00000010
00023 #define DISPLAY_IR_DISPLAY_CONTROL_CURSOR_OFF  0b00000000
00024 #define DISPLAY_IR_DISPLAY_CONTROL_BLINK_ON    0b00000001
00025 #define DISPLAY_IR_DISPLAY_CONTROL_BLINK_OFF   0b00000000
00026 
00027 #define DISPLAY_IR_FUNCTION_SET_8BITS    0b00010000
00028 #define DISPLAY_IR_FUNCTION_SET_4BITS    0b00000000
00029 #define DISPLAY_IR_FUNCTION_SET_2LINES   0b00001000
00030 #define DISPLAY_IR_FUNCTION_SET_1LINE    0b00000000
00031 #define DISPLAY_IR_FUNCTION_SET_5x10DOTS 0b00000100
00032 #define DISPLAY_IR_FUNCTION_SET_5x8DOTS  0b00000000
00033 
00034 #define DISPLAY_20x4_LINE1_FIRST_CHARACTER_ADDRESS 0
00035 #define DISPLAY_20x4_LINE2_FIRST_CHARACTER_ADDRESS 64
00036 #define DISPLAY_20x4_LINE3_FIRST_CHARACTER_ADDRESS 20
00037 #define DISPLAY_20x4_LINE4_FIRST_CHARACTER_ADDRESS 84
00038 
00039 #define DISPLAY_RS_INSTRUCTION 0
00040 #define DISPLAY_RS_DATA        1
00041 
00042 #define DISPLAY_RW_WRITE 0
00043 #define DISPLAY_RW_READ  1
00044 
00045 #define DISPLAY_PIN_RS  4
00046 #define DISPLAY_PIN_RW  5
00047 #define DISPLAY_PIN_EN  6
00048 #define DISPLAY_PIN_D0  7  
00049 #define DISPLAY_PIN_D1  8  
00050 #define DISPLAY_PIN_D2  9  
00051 #define DISPLAY_PIN_D3 10
00052 #define DISPLAY_PIN_D4 11
00053 #define DISPLAY_PIN_D5 12 
00054 #define DISPLAY_PIN_D6 13 
00055 #define DISPLAY_PIN_D7 14 
00056 
00057 #define DISPLAY_PIN_A_PCF8574 3
00058 
00059 #define I2C1_SDA PB_9
00060 #define I2C1_SCL PB_8
00061 
00062 #define PCF8574_I2C_BUS_8BIT_WRITE_ADDRESS 78
00063 
00064 //=====[Declaration of private data types]=====================================
00065 
00066 typedef struct{
00067     int address;
00068     char data;
00069     bool displayPin_RS;
00070     bool displayPin_RW; 
00071     bool displayPin_EN;
00072     bool displayPin_A;
00073     bool displayPin_D4;
00074     bool displayPin_D5;
00075     bool displayPin_D6;
00076     bool displayPin_D7;
00077 } pcf8574_t;
00078 
00079 //=====[Declaration and initialization of public global objects]===============
00080 
00081 DigitalOut displayD0( D0 );
00082 DigitalOut displayD1( D1 );
00083 DigitalOut displayD2( D2 );
00084 DigitalOut displayD3( D3 );
00085 DigitalOut displayD4( D4 );
00086 DigitalOut displayD5( D5 );
00087 DigitalOut displayD6( D6 );
00088 DigitalOut displayD7( D7 );
00089 DigitalOut displayRS( D8 );
00090 DigitalOut displayEN( D9 );
00091 
00092 I2C I2C_PCF8574( I2C1_SDA, I2C1_SCL ); 
00093 
00094 //=====[Declaration of external public global variables]=======================
00095 
00096 //=====[Declaration and initialization of public global variables]=============
00097 
00098 //=====[Declaration and initialization of private global variables]============
00099 
00100 static display_t display;
00101 static pcf8574_t pcf8574;
00102 static bool initial8BitCommunicationIsCompleted;
00103 
00104 //=====[Declarations (prototypes) of private functions]========================
00105 
00106 static void displayPinWrite( uint8_t pinName, int value );
00107 static void displayDataBusWrite( uint8_t dataByte );
00108 static void displayCodeWrite( bool type, uint8_t dataBus );
00109 
00110 //=====[Implementations of public functions]===================================
00111 
00112 void displayInit( displayConnection_t connection )
00113 {
00114     display.connection = connection;
00115     
00116     if( display.connection == DISPLAY_CONNECTION_I2C_PCF8574_IO_EXPANDER) {
00117         pcf8574.address = PCF8574_I2C_BUS_8BIT_WRITE_ADDRESS;
00118         pcf8574.data = 0b00000000;
00119         I2C_PCF8574.frequency(100000);
00120         displayPinWrite( DISPLAY_PIN_A_PCF8574,  ON );
00121     } 
00122     
00123     initial8BitCommunicationIsCompleted = FALSE;    
00124 
00125     delay( 50 );
00126     
00127     displayCodeWrite( DISPLAY_RS_INSTRUCTION, 
00128                       DISPLAY_IR_FUNCTION_SET | 
00129                       DISPLAY_IR_FUNCTION_SET_8BITS );
00130     delay( 5 );
00131             
00132     displayCodeWrite( DISPLAY_RS_INSTRUCTION, 
00133                       DISPLAY_IR_FUNCTION_SET | 
00134                       DISPLAY_IR_FUNCTION_SET_8BITS );
00135     delay( 1 ); 
00136 
00137     displayCodeWrite( DISPLAY_RS_INSTRUCTION, 
00138                       DISPLAY_IR_FUNCTION_SET | 
00139                       DISPLAY_IR_FUNCTION_SET_8BITS );
00140     delay( 1 );  
00141 
00142     switch( display.connection ) {
00143         case DISPLAY_CONNECTION_GPIO_8BITS:
00144             displayCodeWrite( DISPLAY_RS_INSTRUCTION, 
00145                               DISPLAY_IR_FUNCTION_SET | 
00146                               DISPLAY_IR_FUNCTION_SET_8BITS | 
00147                               DISPLAY_IR_FUNCTION_SET_2LINES |
00148                               DISPLAY_IR_FUNCTION_SET_5x8DOTS );
00149             delay( 1 );         
00150         break;
00151         
00152         case DISPLAY_CONNECTION_GPIO_4BITS:
00153         case DISPLAY_CONNECTION_I2C_PCF8574_IO_EXPANDER:
00154             displayCodeWrite( DISPLAY_RS_INSTRUCTION, 
00155                               DISPLAY_IR_FUNCTION_SET | 
00156                               DISPLAY_IR_FUNCTION_SET_4BITS );
00157             delay( 1 );  
00158 
00159             initial8BitCommunicationIsCompleted = TRUE;  
00160 
00161             displayCodeWrite( DISPLAY_RS_INSTRUCTION, 
00162                               DISPLAY_IR_FUNCTION_SET | 
00163                               DISPLAY_IR_FUNCTION_SET_4BITS | 
00164                               DISPLAY_IR_FUNCTION_SET_2LINES |
00165                               DISPLAY_IR_FUNCTION_SET_5x8DOTS );
00166             delay( 1 );                                      
00167         break;
00168     }
00169 
00170     displayCodeWrite( DISPLAY_RS_INSTRUCTION, 
00171                       DISPLAY_IR_DISPLAY_CONTROL |
00172                       DISPLAY_IR_DISPLAY_CONTROL_DISPLAY_OFF |      
00173                       DISPLAY_IR_DISPLAY_CONTROL_CURSOR_OFF |       
00174                       DISPLAY_IR_DISPLAY_CONTROL_BLINK_OFF );       
00175     delay( 1 );          
00176 
00177     displayCodeWrite( DISPLAY_RS_INSTRUCTION, 
00178                       DISPLAY_IR_CLEAR_DISPLAY );       
00179     delay( 1 ); 
00180 
00181     displayCodeWrite( DISPLAY_RS_INSTRUCTION, 
00182                       DISPLAY_IR_ENTRY_MODE_SET |
00183                       DISPLAY_IR_ENTRY_MODE_SET_INCREMENT |       
00184                       DISPLAY_IR_ENTRY_MODE_SET_NO_SHIFT );                  
00185     delay( 1 );           
00186 
00187     displayCodeWrite( DISPLAY_RS_INSTRUCTION, 
00188                       DISPLAY_IR_DISPLAY_CONTROL |
00189                       DISPLAY_IR_DISPLAY_CONTROL_DISPLAY_ON |      
00190                       DISPLAY_IR_DISPLAY_CONTROL_CURSOR_OFF |    
00191                       DISPLAY_IR_DISPLAY_CONTROL_BLINK_OFF );    
00192     delay( 1 );  
00193 }
00194 
00195 void displayCharPositionWrite( uint8_t charPositionX, uint8_t charPositionY )
00196 {    
00197     switch( charPositionY ) {
00198         case 0:
00199             displayCodeWrite( DISPLAY_RS_INSTRUCTION, 
00200                               DISPLAY_IR_SET_DDRAM_ADDR |
00201                               ( DISPLAY_20x4_LINE1_FIRST_CHARACTER_ADDRESS +
00202                                 charPositionX ) );
00203             delay( 1 );         
00204         break;
00205        
00206         case 1:
00207             displayCodeWrite( DISPLAY_RS_INSTRUCTION, 
00208                               DISPLAY_IR_SET_DDRAM_ADDR |
00209                               ( DISPLAY_20x4_LINE2_FIRST_CHARACTER_ADDRESS +
00210                                 charPositionX ) );
00211             delay( 1 );         
00212         break;
00213        
00214         case 2:
00215             displayCodeWrite( DISPLAY_RS_INSTRUCTION, 
00216                               DISPLAY_IR_SET_DDRAM_ADDR |
00217                               ( DISPLAY_20x4_LINE3_FIRST_CHARACTER_ADDRESS +
00218                                 charPositionX ) );
00219             delay( 1 );         
00220         break;
00221 
00222         case 3:
00223             displayCodeWrite( DISPLAY_RS_INSTRUCTION, 
00224                               DISPLAY_IR_SET_DDRAM_ADDR |
00225                               ( DISPLAY_20x4_LINE4_FIRST_CHARACTER_ADDRESS +
00226                                 charPositionX ) );
00227             delay( 1 );         
00228         break;
00229     }
00230 }
00231 
00232 void displayStringWrite( char const * str )
00233 {
00234     while (*str) {
00235         displayCodeWrite(DISPLAY_RS_DATA, *str++);
00236     }
00237 }
00238 
00239 //=====[Implementations of private functions]==================================
00240 
00241 static void displayCodeWrite( bool type, uint8_t dataBus )
00242 {
00243     if ( type == DISPLAY_RS_INSTRUCTION )
00244         displayPinWrite( DISPLAY_PIN_RS, DISPLAY_RS_INSTRUCTION);
00245         else
00246         displayPinWrite( DISPLAY_PIN_RS, DISPLAY_RS_DATA);
00247     displayPinWrite( DISPLAY_PIN_RW, DISPLAY_RW_WRITE );
00248     displayDataBusWrite( dataBus );
00249 }
00250 
00251 static void displayPinWrite( uint8_t pinName, int value )
00252 {
00253     switch( display.connection ) {
00254         case DISPLAY_CONNECTION_GPIO_8BITS:
00255             switch( pinName ) {
00256                 case DISPLAY_PIN_D0: displayD0 = value;   break;
00257                 case DISPLAY_PIN_D1: displayD1 = value;   break;
00258                 case DISPLAY_PIN_D2: displayD2 = value;   break;
00259                 case DISPLAY_PIN_D3: displayD3 = value;   break;
00260                 case DISPLAY_PIN_D4: displayD4 = value;   break;
00261                 case DISPLAY_PIN_D5: displayD5 = value;   break;
00262                 case DISPLAY_PIN_D6: displayD6 = value;   break;
00263                 case DISPLAY_PIN_D7: displayD7 = value;   break;
00264                 case DISPLAY_PIN_RS: displayRS = value;   break;
00265                 case DISPLAY_PIN_EN: displayEN = value;   break;
00266                 case DISPLAY_PIN_RW: break; 
00267                 default: break;
00268             }
00269         case DISPLAY_CONNECTION_GPIO_4BITS:
00270             switch( pinName ) {
00271                 case DISPLAY_PIN_D4: displayD4 = value;   break;
00272                 case DISPLAY_PIN_D5: displayD5 = value;   break;
00273                 case DISPLAY_PIN_D6: displayD6 = value;   break;
00274                 case DISPLAY_PIN_D7: displayD7 = value;   break;
00275                 case DISPLAY_PIN_RS: displayRS = value;   break;
00276                 case DISPLAY_PIN_EN: displayEN = value;   break;
00277                 case DISPLAY_PIN_RW: break; 
00278                 default: break;
00279             }
00280         break;
00281 
00282         case DISPLAY_CONNECTION_I2C_PCF8574_IO_EXPANDER:
00283            if ( value ) {
00284                 switch( pinName ) {
00285                     case DISPLAY_PIN_D4: pcf8574.displayPin_D4 = ON; break;
00286                     case DISPLAY_PIN_D5: pcf8574.displayPin_D5 = ON; break;
00287                     case DISPLAY_PIN_D6: pcf8574.displayPin_D6 = ON; break;
00288                     case DISPLAY_PIN_D7: pcf8574.displayPin_D7 = ON; break;
00289                     case DISPLAY_PIN_RS: pcf8574.displayPin_RS = ON; break;
00290                     case DISPLAY_PIN_EN: pcf8574.displayPin_EN = ON; break;
00291                     case DISPLAY_PIN_RW: pcf8574.displayPin_RW = ON; break;
00292                     case DISPLAY_PIN_A_PCF8574: pcf8574.displayPin_A = ON; break;
00293                     default: break;
00294                 }
00295             }
00296             else {
00297                 switch( pinName ) {
00298                     case DISPLAY_PIN_D4: pcf8574.displayPin_D4 = OFF; break;
00299                     case DISPLAY_PIN_D5: pcf8574.displayPin_D5 = OFF; break;
00300                     case DISPLAY_PIN_D6: pcf8574.displayPin_D6 = OFF; break;
00301                     case DISPLAY_PIN_D7: pcf8574.displayPin_D7 = OFF; break;
00302                     case DISPLAY_PIN_RS: pcf8574.displayPin_RS = OFF; break;
00303                     case DISPLAY_PIN_EN: pcf8574.displayPin_EN = OFF; break;
00304                     case DISPLAY_PIN_RW: pcf8574.displayPin_RW = OFF; break;
00305                     case DISPLAY_PIN_A_PCF8574: pcf8574.displayPin_A = OFF; break;
00306                     default: break;
00307                 }
00308             }     
00309             pcf8574.data = 0b00000000;
00310             if ( pcf8574.displayPin_RS ) pcf8574.data |= 0b00000001; 
00311             if ( pcf8574.displayPin_RW ) pcf8574.data |= 0b00000010; 
00312             if ( pcf8574.displayPin_EN ) pcf8574.data |= 0b00000100; 
00313             if ( pcf8574.displayPin_A  ) pcf8574.data |= 0b00001000; 
00314             if ( pcf8574.displayPin_D4 ) pcf8574.data |= 0b00010000; 
00315             if ( pcf8574.displayPin_D5 ) pcf8574.data |= 0b00100000; 
00316             if ( pcf8574.displayPin_D6 ) pcf8574.data |= 0b01000000; 
00317             if ( pcf8574.displayPin_D7 ) pcf8574.data |= 0b10000000;                                     
00318             I2C_PCF8574.write( pcf8574.address, &pcf8574.data, 1);    
00319         break; 
00320     }
00321 }
00322 
00323 static void displayDataBusWrite( uint8_t dataBus )
00324 {
00325     displayPinWrite( DISPLAY_PIN_EN, OFF );
00326     displayPinWrite( DISPLAY_PIN_D7, dataBus & 0b10000000 );
00327     displayPinWrite( DISPLAY_PIN_D6, dataBus & 0b01000000 );
00328     displayPinWrite( DISPLAY_PIN_D5, dataBus & 0b00100000 );
00329     displayPinWrite( DISPLAY_PIN_D4, dataBus & 0b00010000 );
00330     switch( display.connection ) {
00331         case DISPLAY_CONNECTION_GPIO_8BITS:
00332             displayPinWrite( DISPLAY_PIN_D3, dataBus & 0b00001000 );
00333             displayPinWrite( DISPLAY_PIN_D2, dataBus & 0b00000100 );  
00334             displayPinWrite( DISPLAY_PIN_D1, dataBus & 0b00000010 );      
00335             displayPinWrite( DISPLAY_PIN_D0, dataBus & 0b00000001 );
00336         break; 
00337               
00338         case DISPLAY_CONNECTION_GPIO_4BITS:
00339         case DISPLAY_CONNECTION_I2C_PCF8574_IO_EXPANDER:
00340             if ( initial8BitCommunicationIsCompleted == TRUE) {
00341                 displayPinWrite( DISPLAY_PIN_EN, ON );         
00342                 delay( 1 );
00343                 displayPinWrite( DISPLAY_PIN_EN, OFF );              
00344                 delay( 1 );        
00345                 displayPinWrite( DISPLAY_PIN_D7, dataBus & 0b00001000 );
00346                 displayPinWrite( DISPLAY_PIN_D6, dataBus & 0b00000100 );  
00347                 displayPinWrite( DISPLAY_PIN_D5, dataBus & 0b00000010 );      
00348                 displayPinWrite( DISPLAY_PIN_D4, dataBus & 0b00000001 );                
00349             }
00350         break;
00351     
00352     }
00353     displayPinWrite( DISPLAY_PIN_EN, ON );              
00354     delay( 1 );
00355     displayPinWrite( DISPLAY_PIN_EN, OFF );  
00356     delay( 1 );                   
00357 }