Revision 0:86fab34f85f1, committed 2021-11-10

Comitter:

Sebastien Prouff

Date:

Wed Nov 10 18:47:43 2021 +0100

Commit message:

initial commit

Changed in this revision

diff -r 000000000000 -r 86fab34f85f1 Grove_LCD_RGB_Backlight.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Grove_LCD_RGB_Backlight.cpp	Wed Nov 10 18:47:43 2021 +0100
@@ -0,0 +1,132 @@
+#include "mbed.h"
+#include "Grove_LCD_RGB_Backlight.h"
+char _displayfunction;
+char _displaycontrol;
+
+Grove_LCD_RGB_Backlight::Grove_LCD_RGB_Backlight(PinName sda, PinName scl):i2c(sda, scl)
+{
+    this->init();
+}
+
+/*This function is used to turn on the display on the LCD.  It sends the 
+hexadecimal code for the display on setting to the device in order to 
+turn on the display*/
+
+void Grove_LCD_RGB_Backlight::displayOn() 
+{
+    _displaycontrol |= LCD_DISPLAYON;
+    this->sendCommand(LCD_DISPLAYCONTROL | _displaycontrol);
+}
+
+/*This function is used to clear display on the LCD.  It sends the 
+hexadecimal code for the clear instruction to the device in order to 
+clear the display*/
+void Grove_LCD_RGB_Backlight::clear()
+{
+    this->sendCommand(LCD_CLEARDISPLAY);        
+    wait_us(2000);         
+}
+
+
+/*This function is used to set the backlight color of the dispaly.  
+It writes the provided r, g, and b values to the registers for the red
+value, the green value, and the blue value respectively.*/
+void Grove_LCD_RGB_Backlight::setRGB(char r, char g, char b)
+{
+   
+    this->setReg(RED_REG, r);
+    this->setReg(GREEN_REG, g);
+    this->setReg(BLUE_REG, b);  
+    
+}
+
+/*This function is used to write to one of the registers for the backlight
+of the LCD display.  The function takes in the address of which register to
+write to and the value to be written to that register and then sends it to the
+LCD display via the mbed I2C library*/
+void Grove_LCD_RGB_Backlight::setReg(char addr, char val)
+{
+    char data[2];
+    data[0] = addr;
+    data[1] = val;
+    i2c.write(RGB_ADDRESS, data, 2);
+}
+
+/*This function is used to write to the LCD screen.  It takes in a string of
+characters and writes them to the 0x40 register of the display.*/
+void Grove_LCD_RGB_Backlight::print(char *str)
+{   
+    char data[2];
+    data[0] = 0x40;
+    while(*str)
+    {
+            data[1] = *str;
+            i2c.write(LCD_ADDRESS, data, 2);
+            str++;
+            
+    }
+
+
+}
+
+
+/*This function sets where on the screen the text will be written next.  It 
+takes in two values which indicate the row and column on the display that 
+the cursor should be moved to*/
+void Grove_LCD_RGB_Backlight::locate(char col, char row)
+{
+    if(row == 0)
+    {
+        col = col | 0x80;
+    }
+    else
+    {   
+        col = col | 0xc0;
+    }
+ 
+    char data[2];
+    data[0] = 0x80;
+    data[1] = col;
+    i2c.write(LCD_ADDRESS, data, 2);
+}
+
+/*This function sends an instruction to the LCD display using the
+ built in instruction codes from the device  datasheet using the mbed
+ I2C library*/
+void Grove_LCD_RGB_Backlight::sendCommand(char value)
+{
+    char data[2] = {0x80, value};
+    i2c.write(LCD_ADDRESS, data, 2);
+}
+
+void Grove_LCD_RGB_Backlight::init() 
+{   
+    //Initialize displayfunction parameter for setting up LCD display
+   _displayfunction |= LCD_2LINE;
+   _displayfunction |= LCD_5x10DOTS;
+ 
+   //Wait for more than 30 ms after power rises above 4.5V per the data sheet
+    //wait_ms(50);
+    wait_us(50000);
+
+    // Send first function set command. Wait longer that 39 us per the data sheet
+    sendCommand(LCD_FUNCTIONSET | _displayfunction);
+    wait_us(45);  
+    
+    // turn the display on
+    displayOn();
+
+    // clear the display
+    clear();
+    
+    // Initialize backlight
+    setReg(0, 0);
+    setReg(1, 0);
+    setReg(0x08, 0xAA);   
+    
+
+
+    
+
+}
+

diff -r 000000000000 -r 86fab34f85f1 Grove_LCD_RGB_Backlight.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Grove_LCD_RGB_Backlight.h	Wed Nov 10 18:47:43 2021 +0100
@@ -0,0 +1,85 @@
+#include "mbed.h"
+
+// I2C addresses for LCD and RGB
+#define LCD_ADDRESS     (0x7c)
+#define RGB_ADDRESS     (0xc4)
+
+#define RED_REG         0x04        
+#define GREEN_REG       0x03        
+#define BLUE_REG        0x02        
+
+// commands
+#define LCD_CLEARDISPLAY 0x01
+#define LCD_DISPLAYCONTROL 0x08
+#define LCD_FUNCTIONSET 0x20
+
+// flags for display on/off control
+#define LCD_DISPLAYON 0x04
+#define LCD_DISPLAYOFF 0x00
+
+// flag for entry mode
+#define LCD_ENTRYLEFT 0x02
+
+// flags for function set
+#define LCD_8BITMODE 0x10
+#define LCD_2LINE 0x08
+#define LCD_5x10DOTS 0x04
+
+/** Grove_LCD_RGB_Backlight Class.
+*   Used for connecting a Grove LCD RGB Backlit display
+*   to an mbed microcontroller via an I2C interface.
+*/    
+class Grove_LCD_RGB_Backlight
+{
+public:
+    
+    /** Contructor. Creates an instance of the Grove_LCD_RGB_Backlight class.
+    *   @param sda SDA pin on the mbed microcontroller which will be used to communicate with the display.
+    *   @param scl SCL pin on the mbed microcontroller which will be used to communicate with the display.
+    */
+    Grove_LCD_RGB_Backlight(PinName sda, PinName scl); 
+    
+
+    
+    /** Set RGB color of backlight
+    *   @param r Value for the red component of the RGB backlight (Between 0 and 255).
+    *   @param g Value for the green component of the RGB backlight (Between 0 and 255).
+    *   @param b Value for the blue component of the RGB backlight (Between 0 and 255).
+    */
+    void setRGB(char r, char g, char b);     
+    
+    
+    /** Removes all of the text from the display.
+    */
+    void clear();
+    
+    /**Prints text to the LCD display.
+    * @param *str Pointer to an array of characters which will be printed to the LCD screen.
+    */
+    void print(char *str);
+    
+    /**Move cursor to specified location on the LCD screen.
+    * @param col Value for which column on the display the next text being printed will start at.
+    * @param row Value for which row on the display the next text being printed will be printed on.
+    */
+    void locate(char col, char row);
+
+    
+private:
+    
+    //Initialize device
+    void init();   
+    
+    //Turn on display
+    void displayOn();
+    
+    //Send command to display
+    void sendCommand(char value);
+    
+    //Set register value
+    void setReg(char addr, char val);
+    
+    //MBED I2C object used to transfer data to LCD
+    I2C i2c;              
+    
+};
\ No newline at end of file