// *************************************************************************//
//     Example program to place characters on an LCD display                //  
//                                                                          //
//   Filename:  lcd_4bit_demo.c                                             //
//   Author:    L.Aamodt                                                    //
//   Version:   01/27/19 written                                            //
//              01/29/20 added port C clock enable                          //
//   Processor: NXP MKL25Z4                                                 //
//   Compiler:  Keil uVision5                                               //
//   Library:   CMSIS core and device startup                               //
//              also needs lcd_lib_4bit.c                                   //
//   Hardware:  NXP Freedom board connected to a 16x2 LCD display           //
//   Software note:  This program is a "bare metal" application since it    //
//              doesn't use an operating system.                            //
//   Operation: Writes 11 alpha characters (F to P) to LCD display.         //
//              Blinks red LED on for 1 second, off for 1 second            //
// *************************************************************************//
# include <MKL25Z4.h>

#define RED_LED_SHIFT   (18)  // on port B
#define GREEN_LED_SHIFT (19)  // on port B (not used in this program)
#define BLUE_LED_SHIFT  (1)   // on port D (not used in this program)

#define MASK(x) (1UL << (x))

void LCD_init(void);
void LCD_command(uint32_t command);       // use to send LCD commands
void LCD_send_data(uint32_t data);        // use to send one char to screen
void delayMs(uint32_t n);

int main(void) {
	uint32_t j;
	// Enable clock to Ports B and C
	SIM->SCGC5 |= SIM_SCGC5_PORTB_MASK;
	SIM->SCGC5 |= SIM_SCGC5_PORTC_MASK;

	// Make red RGB LED pin GPIO
	PORTB->PCR[RED_LED_SHIFT] &= ~PORT_PCR_MUX_MASK;
	PORTB->PCR[RED_LED_SHIFT] |= PORT_PCR_MUX(1);
	
	// Set port pin direction to output
	PTB->PDDR |=MASK(RED_LED_SHIFT);
	
	LCD_init();                   // initialize LCD display
	LCD_command(0x01);            // example command: clear screen
	
	for (j=97;j<103;j++) {
		LCD_send_data(j);     // example data: output lower abcdefg
        }
	LCD_command(0xC0);            // move cursor to line 2

	for (j=72;j<79;j++) {
		LCD_send_data(j);     // example data: output caps ABCDEFG

	}

	while(1) {
       // alternately turn red LED on/off just to show that CPU is running
		PTB->PCOR |= MASK(RED_LED_SHIFT);
		delayMs(1000);
		PTB->PSOR |= MASK(RED_LED_SHIFT);
		delayMs(1000);

	}
}