Diff: N5110/N5110.cpp

Revision:

0:5bdb67970267

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/N5110/N5110.cpp	Fri Aug 08 06:44:50 2014 +0000
@@ -0,0 +1,259 @@
+/**
+@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 model
+    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);
+}
+ 
+unsigned char N5110::getPixel(int x, int y)
+{
+    // return relevant bank and mask required bit
+    return buffer[x][y/8] & (1 << y%8);
+ 
+}
+ 
+// function to refresh the display
+void N5110::refresh()
+{
+    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
+ 
+}
+ 
+// 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 i;
+    // loop through 5 columns
+    for (i = 0; i < 5 ; i++ ) {
+        sendData(font5x7[(c - 32)*5 + i]);
+        // array is offset by 32 relative to ASCII, each character is 5 pixels wide
+        // the X address is automatically incremented after each data write
+    }
+    sendData(0); // send an empty byte to introduce space between characters
+ 
+}
+ 
+// 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);   // print the char - can probably so *str++ and remove next line
+        str++;  // go to next character in string
+        n++;    // increment index
+    }
+ 
+}
+ 
+// 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;
+        }
+    }
+}