Updated for mbed: Simple library for interfacing to Nokia 5110 LCD display (as found on the SparkFun website).

Fork of N5110 by Craig Evans

Revision:
0:d563e74f0ae9
Child:
1:df68f34cd32d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/N5110.cpp	Sun Jan 26 18:55:16 2014 +0000
@@ -0,0 +1,218 @@
+#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;
+        }
+    }
+}
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