/* * LCD interface example * Uses routines from delay.c * This code will interface to a standard LCD controller * like the Hitachi HD44780. It uses it in 4 bit mode, with * the hardware connected as follows (the standard 14 pin * LCD connector is used): * * PORTB bits 0-3 are connected to the LCD data bits 4-7 (high nibble) * PORTA bit 2 is connected to the LCD RS input (register select) * PORTA bit 3 is connected to the LCD EN bit (enable) * * To use these routines, set up the port I/O (TRISA, TRISB) then * call lcd_init(), then other routines as required. * * Copywrite Craig Lee 1998 * */ #include <pic.h> #include "lcd.h" #include "delay.h" #define LCD_RS RA5 // Register select #define LCD_EN RB4 // Enable #define LCD_D4 RB5 // Data bits #define LCD_D5 RC5 // Data bits #define LCD_D6 RC4 // Data bits #define LCD_D7 RC3 // Data bits #define LCD_STROBE ((LCD_EN = 1),(LCD_EN=0)) /* write a byte to the LCD in 4 bit mode */ void lcd_write(unsigned char c) { if(c & 0x80) LCD_D7=1; else LCD_D7=0; if(c & 0x40) LCD_D6=1; else LCD_D6=0; if(c & 0x20) LCD_D5=1; else LCD_D5=0; if(c & 0x10) LCD_D4=1; else LCD_D4=0; LCD_STROBE; if(c & 0x08) LCD_D7=1; else LCD_D7=0; if(c & 0x04) LCD_D6=1; else LCD_D6=0; if(c & 0x02) LCD_D5=1; else LCD_D5=0; if(c & 0x01) LCD_D4=1; else LCD_D4=0; LCD_STROBE; DelayUs(40); } /* * Clear and home the LCD */ void lcd_clear(void) { LCD_RS = 0; lcd_write(0x1); DelayMs(2); } /* write a string of chars to the LCD */ void lcd_puts(const char * s) { LCD_RS = 1; // write characters while(*s) lcd_write(*s++); } /* write one character to the LCD */ void lcd_putch(unsigned char c) { LCD_RS = 1; // write characters lcd_write(c); } /* * Go to the specified position */ void lcd_goto(unsigned char pos) { LCD_RS = 0; lcd_write(0x80 + pos); } /* initialise the LCD - put into 4 bit mode */ void lcd_init(void) { LCD_RS = 0; // write control bytes DelayMs(15);// power on delay LCD_D4 = 1; // init! LCD_D5 = 1; // LCD_STROBE; DelayMs(5); LCD_STROBE; // init! DelayUs(100); LCD_STROBE; // init! DelayMs(5); LCD_D4 = 0; // set 4 bit mode LCD_STROBE; DelayUs(40); lcd_write(0x28);// 4 bit mode, 1/16 duty, 5x8 font, 2lines lcd_write(0x0C);// display on lcd_write(0x06);// entry mode advance cursor lcd_write(0x01);// clear display and reset cursor }
Questions:
Hello, Has anyone had experience with driving a Laptop LCD display, I have a one from an old laptop as was wondering if a PIC could be used to drive it, It is a panasonic cf27 laptop and the dispaly is a standard 640x480 lcd, any ideas and or source code would be very appreciated. Best regards Nick
Code:
//**Project Name: VFD //**File Name : vfd0_3.c //**Version : 0.3 //**Date : 24/02/2002 //**Revision : 28/02/2002 added bit swap routine //** : 02/03/2002 fixed error in display routine and added delay to //** : WR_PIN strobe. //** : //** //**Processor :16F84/628 //** //** Copyright CDB. email bodgy1@optusnet.com.au // Program to display data on a Futoba M202SD08GL vacuum fluorescent display. // Using parallel mode. Data is on port B and control on port A. // Connections as follows // // Display Pins. 1 3 5 7 9 11 13 15 // Data Bits. 7 6 5 4 3 2 1 0 // // Control Pins. 20 18 17 16 8 // Signal Name. Busy SEL WR TEST RST // // Pins 2 4 6 +5v; 10 12 14 Gnd // Pic Pins B7 B6 B5 B4 B3 B2 B1 B0 // D0 D1 D2 D3 D4 D5 D6 D7 // // PortA A0 A1 A2 A3 A4 // WR SEL TEST RST BUSY // A0-A3 output A4 input. // // WR, SEL active low. data latched on WR 0->1; RST must be momentarily grounded // at start up to activate display. #define F628 #ifdef F628 #include <P16F628.h> #else #include <P16F84.h> #endif #include "uS_delay.c" #define CONTROL_PORT PORTA #define DATA_PORT PORTB #define WR_PIN PA.B0 #define SEL_PIN PA.B1 #define TEST_PIN PA.B2 #define RST_PIN PA.B3 #define BUSY_PIN PA.B4 #define HIGH 1 #define LOW 0 #define STROBE (PORTA^=1) #define MAX_ROW 20 #define LINES 2 // VFD Control Commands #define LF 0x0A //Line Feed #define CR 0x0D //Carriage Return #define CUROFF 0x14 //DC4 #define CURON 0x13 //DC3 #define DIMM 0x04 //Dimming uses vfd_command #define DIM2 0x20 //Dimm 20% #define DIM4 0x40 //Dimm 40% #define DIM8 0x80 //Dimm 80% #define DIMF 0xFF //Dimm 100% #define VTS 0x12 //DC2 Mode #define NORM 0x11 //DC1 Mode #define HTS 0x09 //Tab right one space #define BSP 0x09 //Backspace #define DP 0x10 //Display position uses vfd_command #define RST 0x1F //Soft reset #ifdef F628 # __config 0x3F61 //16F628 fuse #else # __config 0x3FF1 //16F84(a) fuse #endif //Prototypes void main(); void setup(); void reset_vfd(); void test_vfd(); void vfd_display(unsigned char *disp_string); void vfd_out(unsigned char *text); void vfd_ch(unsigned char ch); void vfd_command(unsigned char com, unsigned char action); void vfd_position(unsigned char line,unsigned char pos); void main() { setup(); big_delay(10); //settling time reset_vfd(); //Hard reset test_vfd(); //Run inbuilt test routine SEL_PIN=LOW; //Enable display for data big_delay(10); vfd_ch(CUROFF); vfd_display("Futoba VFD Display"); big_delay(3000); vfd_command(LF,CR); vfd_display("Dimming 20%"); vfd_command(DIMM,DIM2); //20% brightness big_delay(5000); vfd_command(DIMM,DIMF); //Full brightness vfd_ch(RST); // Clear display vfd_ch(CUROFF); vfd_command(CR,LF); vfd_display("pos"); vfd_position(2,5); vfd_display("2,5"); big_delay(5000); vfd_ch(VTS); vfd_display(" vertical tab"); big_delay(5000); vfd_ch(RST); vfd_ch(CUROFF); vfd_display("Futoba VFD Display"); vfd_position(2,5); vfd_display("End of Demo"); vfd_command(DIMM,DIM4); //40% brightness while(1) { } //forever! } // cmcon=(1<<CM2) |(1<<CM1) |(1<<CM0) void setup() { #ifdef F628 CMCON=0x07; // switch comparators off #endif CONTROL_PORT=0x0E; // RST=1 TEST=1 SEL=1 WR=0 DATA_PORT=0; TRISA=0x10; //PortA A4=in a4:a0 out TRISB=0x00; } void reset_vfd() { RST_PIN=LOW; //Take reset pin low to awake VFD small_delay(1); //12 microsecond settling time RST_PIN=HIGH; //Return reset pin to operating state } void test_vfd() { TEST_PIN=LOW; big_delay(28000); // delay 20 seconds approx TEST_PIN=HIGH; } void vfd_display(unsigned char *string) { while(*string) //while not end of string { vfd_out(string); *string++; //move to next character } } // Following routine only required due to pin out chosen. This was chosen from // a PCB perspective. // // D7 D6 D5 D4 D3 D2 D1 D0 -> D0 D1 D2 D3 D4 D5 D6 D7 // // Using the extra variable 'original1' saves 3 program words unsigned char buffer,original; void vfd_out(unsigned char *text) { const unsigned char table[16]= {0x00, 0x08, 0x04, 0x0C, 0x02, 0x0A, 0x06, 0x0E, 0x01, 0x09, 0x05, 0x0D, 0x03, 0x0B, 0x07,0x0F}; unsigned char original1; original=*text; original1=original & 0x0f; // Mask off lower nibble buffer=table[original1]; //look up conversion pattern lower nibble #asmline swapf buffer,f ;swap places make it high nibble #asmline swapf original,f ;swap original byte around original&=0x0f; buffer|=table[original]; //look up pattern for new lower nibble //IOR with current contents DATA_PORT=buffer; //Bung it on to PORTB while (BUSY_PIN) { } STROBE; //Clock the data into the VFD small_delay(30); //100 microseconds STROBE; //Return pin low } void vfd_ch(unsigned char ch) { unsigned char *text; text=&ch; vfd_out(text); } void vfd_command(unsigned char com, unsigned char action) { vfd_ch(com); vfd_ch(action); } void vfd_position(unsigned char line,unsigned char pos) { if (line==LINES) { pos+=(MAX_ROW-1); } else { pos=-1; } vfd_command(DP,pos); }
Code for a vacuum flourescent display in C //**Project Name: VFD //**File Name : vfd0_3.c //**Version : 0.3 //**Date : 24/02/2002 //**Revision : 28/02/2002 added bit swap routine //** : 02/03/2002 fixed error in display routine and added delay to //** : WR_PIN strobe. //** : //** //**Processor :16F84/628 //** //** Copyright CDB. email bodgy1@optusnet.com.au // Program to display data on a Futoba M202SD08GL vacuum fluorescent display. // Using parallel mode. Data is on port B and control on port A. // Connections as follows // // Display Pins. 1 3 5 7 9 11 13 15 // Data Bits. 7 6 5 4 3 2 1 0 // // Control Pins. 20 18 17 16 8 // Signal Name. Busy SEL WR TEST RST // // Pins 2 4 6 +5v; 10 12 14 Gnd // Pic Pins B7 B6 B5 B4 B3 B2 B1 B0 // D0 D1 D2 D3 D4 D5 D6 D7 // // PortA A0 A1 A2 A3 A4 // WR SEL TEST RST BUSY // A0-A3 output A4 input. // // WR, SEL active low. data latched on WR 0->1; RST must be momentarily grounded // at start up to activate display. #define F628 #ifdef F628 #include <P16F628.h> #else #include <P16F84.h> #endif #include "uS_delay.c" #define CONTROL_PORT PORTA #define DATA_PORT PORTB #define WR_PIN PA.B0 #define SEL_PIN PA.B1 #define TEST_PIN PA.B2 #define RST_PIN PA.B3 #define BUSY_PIN PA.B4 #define HIGH 1 #define LOW 0 #define STROBE (PORTA^=1) #define MAX_ROW 20 #define LINES 2 // VFD Control Commands #define LF 0x0A //Line Feed #define CR 0x0D //Carriage Return #define CUROFF 0x14 //DC4 #define CURON 0x13 //DC3 #define DIMM 0x04 //Dimming uses vfd_command #define DIM2 0x20 //Dimm 20% #define DIM4 0x40 //Dimm 40% #define DIM8 0x80 //Dimm 80% #define DIMF 0xFF //Dimm 100% #define VTS 0x12 //DC2 Mode #define NORM 0x11 //DC1 Mode #define HTS 0x09 //Tab right one space #define BSP 0x09 //Backspace #define DP 0x10 //Display position uses vfd_command #define RST 0x1F //Soft reset #ifdef F628 # __config 0x3F61 //16F628 fuse #else # __config 0x3FF1 //16F84(a) fuse #endif //Prototypes void main(); void setup(); void reset_vfd(); void test_vfd(); void vfd_display(unsigned char *disp_string); void vfd_out(unsigned char *text); void vfd_ch(unsigned char ch); void vfd_command(unsigned char com, unsigned char action); void vfd_position(unsigned char line,unsigned char pos); void main() { setup(); big_delay(10); //settling time reset_vfd(); //Hard reset test_vfd(); //Run inbuilt test routine SEL_PIN=LOW; //Enable display for data big_delay(10); vfd_ch(CUROFF); vfd_display("Futoba VFD Display"); big_delay(3000); vfd_command(LF,CR); vfd_display("Dimming 20%"); vfd_command(DIMM,DIM2); //20% brightness big_delay(5000); vfd_command(DIMM,DIMF); //Full brightness vfd_ch(RST); // Clear display vfd_ch(CUROFF); vfd_command(CR,LF); vfd_display("pos"); vfd_position(2,5); vfd_display("2,5"); big_delay(5000); vfd_ch(VTS); vfd_display(" vertical tab"); big_delay(5000); vfd_ch(RST); vfd_ch(CUROFF); vfd_display("Futoba VFD Display"); vfd_position(2,5); vfd_display("End of Demo"); vfd_command(DIMM,DIM4); //40% brightness while(1) { } //forever! } // cmcon=(1<<CM2) |(1<<CM1) |(1<<CM0) void setup() { #ifdef F628 CMCON=0x07; // switch comparators off #endif CONTROL_PORT=0x0E; // RST=1 TEST=1 SEL=1 WR=0 DATA_PORT=0; TRISA=0x10; //PortA A4=in a4:a0 out TRISB=0x00; } void reset_vfd() { RST_PIN=LOW; //Take reset pin low to awake VFD small_delay(1); //12 microsecond settling time RST_PIN=HIGH; //Return reset pin to operating state } void test_vfd() { TEST_PIN=LOW; big_delay(28000); // delay 20 seconds approx TEST_PIN=HIGH; } void vfd_display(unsigned char *string) { while(*string) //while not end of string { vfd_out(string); *string++; //move to next character } } // Following routine only required due to pin out chosen. This was chosen from // a PCB perspective. // // D7 D6 D5 D4 D3 D2 D1 D0 -> D0 D1 D2 D3 D4 D5 D6 D7 // // Using the extra variable 'original1' saves 3 program words unsigned char buffer,original; void vfd_out(unsigned char *text) { const unsigned char table[16]= {0x00, 0x08, 0x04, 0x0C, 0x02, 0x0A, 0x06, 0x0E, 0x01, 0x09, 0x05, 0x0D, 0x03, 0x0B, 0x07,0x0F}; unsigned char original1; original=*text; original1=original & 0x0f; // Mask off lower nibble buffer=table[original1]; //look up conversion pattern lower nibble #asmline swapf buffer,f ;swap places make it high nibble #asmline swapf original,f ;swap original byte around original&=0x0f; buffer|=table[original]; //look up pattern for new lower nibble //IOR with current contents DATA_PORT=buffer; //Bung it on to PORTB while (BUSY_PIN) { } STROBE; //Clock the data into the VFD small_delay(30); //100 microseconds STROBE; //Return pin low } void vfd_ch(unsigned char ch) { unsigned char *text; text=&ch; vfd_out(text); } void vfd_command(unsigned char com, unsigned char action) { vfd_ch(com); vfd_ch(action); } void vfd_position(unsigned char line,unsigned char pos) { if (line==LINES) { pos+=(MAX_ROW-1); } else { pos=-1; } vfd_command(DP,pos); }
Comments:
file: /Techref/microchip/language/c/io/lcd/hitachilcd-cl/lcd_c.htm, 23KB, , updated: 2009/11/13 13:19, local time: 2024/11/4 13:19,
34.204.176.71:LOG IN ©2024 PLEASE DON'T RIP! THIS SITE CLOSES OCT 28, 2024 SO LONG AND THANKS FOR ALL THE FISH!
|
©2024 These pages are served without commercial sponsorship. (No popup ads, etc...).Bandwidth abuse increases hosting cost forcing sponsorship or shutdown. This server aggressively defends against automated copying for any reason including offline viewing, duplication, etc... Please respect this requirement and DO NOT RIP THIS SITE. Questions? <A HREF="http://techref.massmind.org/techref/microchip/language/c/io/lcd/hitachilcd-cl/lcd_c.htm"> LCD interface example</A> |
Did you find what you needed? |
Welcome to massmind.org! |
Welcome to techref.massmind.org! |
.