Yang Junyao 201090191
N5110.cpp
- Committer:
- eencae
- Date:
- 2015-03-10
- Revision:
- 14:520a02fc12aa
- Parent:
- 12:022993561fd8
- Child:
- 15:ee645611ff94
File content as of revision 14:520a02fc12aa:
/** @file N5110.cpp @brief Member functions implementations */ #include "mbed.h" #include "N5110.h" N5110::N5110(PinName pwrPin, PinName scePin, PinName rstPin, PinName dcPin, PinName mosiPin, PinName sclkPin, PinName ledPin) { spi = new SPI(mosiPin,NC,sclkPin); // create new SPI instance and initialise initSPI(); // set up pins as required led = new PwmOut(ledPin); pwr = new DigitalOut(pwrPin); sce = new DigitalOut(scePin); rst = new DigitalOut(rstPin); dc = new DigitalOut(dcPin); } // initialise function - powers up and sends the initialisation commands void N5110::init() { turnOn(); // power up wait_ms(10); // small delay seems to prevent spurious pixels during mbed reset reset(); // reset LCD - must be done within 100 ms // function set - extended sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_EXTENDED_MODE); // Don't completely understand these parameters - they seem to work as they are // Consult the datasheet if you need to change them sendCommand(CMD_VOP_7V38); // operating voltage - these values are from Chris Yan's Library 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); normalMode(); // normal video mode by default sendCommand(CMD_DC_NORMAL_MODE); // black on white // RAM is undefined at power-up so clear clearRAM(); } // sets normal video mode (black on white) void N5110::normalMode() { sendCommand(CMD_DC_NORMAL_MODE); } // sets normal video mode (white on black) void N5110::inverseMode() { sendCommand(CMD_DC_INVERT_VIDEO); } // 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 // send command to ensure we are in basic mode sendCommand(0x20 | CMD_FS_ACTIVE_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_BASIC_MODE); // clear the display sendCommand(CMD_DC_CLEAR_DISPLAY); // enter the extended mode and power down sendCommand(0x20 | CMD_FS_POWER_DOWN_MODE | CMD_FS_HORIZONTAL_MODE | CMD_FS_EXTENDED_MODE); // small delay and then turn off the power pin wait_ms(10); 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 } // send a command to the display 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) } // send data to the display at the current XY address // dc is set to 1 (i.e. data) after sending a command and so should // be the default mode. 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 } // function to set the XY address in RAM for subsequenct data write void N5110::setXYAddress(int x, int y) { // check whether address is in range if (x > 83) x=83; if (y > 5) y=5; if (x < 0) x=0; if (y < 0) y=0; sendCommand(0x80 | x); // send addresses to display with relevant mask sendCommand(0x40 | y); } // These functions are used to set, clear and get the value of pixels in the display // Pixels are addressed in the range of 0 to 47 (y) and 0 to 83 (x). The refresh() // function must be called after set and clear in order to update the display void N5110::setPixel(int x, int y) { // calculate bank and shift 1 to required position in the data byte 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); } int N5110::getPixel(int x, int y) { // return relevant bank and mask required bit return (int) buffer[x][y/8] & (1 << y%8); } // function to refresh the display void N5110::refresh() { int i,j; setXYAddress(0,0); // important to set address back to 0,0 before refreshing display // address auto increments after printing string, so buffer[0][0] will not coincide // with top-left pixel after priting string 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 } // fills the buffer with random bytes. Can be used to test the display. // The rand() function isn't seeded so it probably creates the same pattern everytime 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,int x,int y) { for (int i = 0; i < 5 ; i++ ) { buffer[x+i][y] = font5x7[(c - 32)*5 + i]; // array is offset by 32 relative to ASCII, each character is 5 pixels wide } refresh(); // this sends the buffer to the display and sets address (cursor) back to 0,0 } // 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) { // writes the character bitmap data to the buffer, so that // text and pixels can be displayed at the same time for (int i = 0; i < 5 ; i++ ) { buffer[x+i+n*6][y] = font5x7[(*str - 32)*5 + i]; } str++; // go to next character in string n++; // increment index } refresh(); // this sends the buffer to the display and sets address (cursor) back to 0,0 } // function to clear the screen void N5110::clear() { clearBuffer(); // clear the buffer then call the refresh function refresh(); } // function to clear the buffer void N5110::clearBuffer() { int i,j; for (i=0; i<84; i++) { // loop through the banks and set the buffer to 0 for (j=0; j<6; j++) { buffer[i][j]=0; } } } // function to plot array on display void N5110::plotArray(float array[]) { int i; for (i=0; i<84; i++) { // loop through array // elements are normalised from 0.0 to 1.0, so multiply // by 47 to convert to pixel range, and subtract from 47 // since top-left is 0,0 in the display geometry setPixel(i,47 - int(array[i]*47.0)); } refresh(); }