Simple library for interfacing to Nokia 5110 LCD display (as found on the SparkFun website). Edited to include additional feaatures, such as 2d array loading, multiple screen buffers, and better backlight control
Dependencies: N5110
Fork of N5110 by
N5110.cpp
- Committer:
- eencae
- Date:
- 2014-01-26
- Revision:
- 0:d563e74f0ae9
- Child:
- 1:df68f34cd32d
File content as of revision 0:d563e74f0ae9:
#include "mbed.h" #include "N5110.h" N5110::N5110(PinName pwrPin, PinName ledPin, PinName scePin, PinName rstPin, PinName dcPin, PinName mosiPin, PinName sclkPin) { spi = new SPI(mosiPin,NC,sclkPin); // create new SPI instance and initialise initSPI(); led = new PwmOut(ledPin); pwr = new DigitalOut(pwrPin); sce = new DigitalOut(scePin); rst = new DigitalOut(rstPin); dc = new DigitalOut(dcPin); } void N5110::init() { turnOn(); // power up reset(); // reset LCD // function set - extended sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_EXTENDED_MODE); sendCommand(CMD_VOP_7V38); // operating voltage sendCommand(CMD_TC_TEMP_2); // temperature control sendCommand(CMD_BI_MUX_48); // bias // function set - basic sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_BASIC_MODE); sendCommand(CMD_DC_NORMAL_MODE); // black on white //sendLCDCommand(CMD_DC_INVERT_VIDEO); // white on black // RAM is undefined at power-up so clear clearRAM(); } // function to power up the LCD and backlight void N5110::turnOn() { // set brightness of LED - 0.0 to 1.0 - default is 50% setBrightness(0.5); pwr->write(1); // apply power } // function to power down LCD void N5110::turnOff() { setBrightness(0.0); // turn backlight off clearRAM(); // clear RAM to ensure specified current consumption sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_BASIC_MODE); sendCommand(CMD_DC_CLEAR_DISPLAY); sendCommand(0x20 | CMD_FS_POWER_DOWN_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_EXTENDED_MODE); pwr->write(0); } // function to change LED backlight brightness void N5110::setBrightness(float brightness) { // check whether brightness is within range if (brightness < 0.0) brightness = 0.0; if (brightness > 1.0) brightness = 1.0; // set PWM duty cycle led->write(brightness); } // pulse the active low reset line void N5110::reset() { rst->write(0); // reset the LCD rst->write(1); } // function to initialise SPI peripheral void N5110::initSPI() { spi->format(8,1); // 8 bits, Mode 1 - polarity 0, phase 1 - base value of clock is 0, data captured on falling edge/propagated on rising edge spi->frequency(4000000); // maximum of screen is 4 MHz } void N5110::sendCommand(unsigned char command) { dc->write(0); // set DC low for command sce->write(0); // set CE low to begin frame spi->write(command); // send command dc->write(1); // turn back to data by default sce->write(1); // set CE high to end frame (expected for transmission of single byte) } void N5110::sendData(unsigned char data) { sce->write(0); // set CE low to begin frame spi->write(data); sce->write(1); // set CE high to end frame (expected for transmission of single byte) } // this function writes 0 to the 504 bytes to clear the RAM void N5110::clearRAM() { int i; sce->write(0); //set CE low to begin frame for(i = 0; i < 504; i++) { // 48 x 84 bits = 504 bytes spi->write(0x00); // send 0's } sce->write(1); // set CE high to end frame } void N5110::setXYAddress(int x, int y) { // check whether address is in range if (x > 83) x=83; if (y > 5) y=5; sendCommand(0x80 | x); sendCommand(0x40 | y); } void N5110::setPixel(int x, int y) { // calculate bank and shift 1 to required position buffer[x][y/8] |= (1 << y%8); } void N5110::clearPixel(int x, int y) { // calculate bank and shift 1 to required position (using bit clear) buffer[x][y/8] &= ~(1 << y%8); } unsigned char N5110::getPixel(int x, int y) { // return relevant bank and mask required bit return buffer[x][y/8] & (1 << y%8); } void N5110::refreshDisplay() { int i,j; sce->write(0); //set CE low to begin frame for(j = 0; j < 6; j++) { // be careful to use correct order (j,i) for horizontal addressing for(i = 0; i < 84; i++) { spi->write(buffer[i][j]); // send buffer } } sce->write(1); // set CE high to end frame } void N5110::randomiseBuffer() { int i,j; for(j = 0; j < 6; j++) { // be careful to use correct order (j,i) for horizontal addressing for(i = 0; i < 84; i++) { buffer[i][j] = rand()%256; // generate random byte } } } // function to print 5x7 font void N5110::printChar(char c) { // loop through 5 columns for (int j = 0; j < 5 ; j++ ) { sendData(font5x7[(c - 32)*5 + j]); // array is offset by 32 relative to ASCII, each character is 5 pixels wide } } // function to print string at specified position void N5110::printString(const char * str,int x,int y) { int n = 0 ; // counter for number of characters in string // loop through string and print character while(*str) { setXYAddress(x+6*n,y); // leave 1 pixel (6 = 5 + 1) between each character printChar(*str); str++; // go to next character in string n++; // increment index } } void N5110::clear() { clearBuffer(); refreshDisplay(); } void N5110::clearBuffer() { int i,j; for (i=0; i<84; i++) { for (j=0; j<6; j++) { buffer[i][j]=0; } } }