MSP430 Segment-LCD Ghosting reduzieren

#include <msp430.h>

#include <stdbool.h>

#include <stdint.h>

#define pm5_unlock() (PM5CTL0 &= ~LOCKLPM5)

#define lcd_mem_clr()   (LCDMEMCTL |= LCDCLRM)

const uint8_t lcd_segment_map[] = {

        0xd7,

        0x06,

        0xe3,

        0xa7,

        0x36,

        0xb5,

        0xfd,

        0x07,

        0xf7,

        0xb7

};

void lcd_init ()

{

        LCDCTL0 = 0x0000; // LCD_E module off

        /* LCD clock is VLOCLK,

         * mux rate is 4-mux,

         * prescaler 1 */

        LCDCTL0 = (LCDSSEL1 | LCDMX0 | LCDMX1 | LCDSON);

        /* enable charge pump,

         * R33 is supplied from Vcc internally */

        LCDVCTL |= (LCDCPEN | LCDSELVDD);

        lcd_mem_clr();

        /* Pin definitions */

        LCDPCTL0 = 0x0f00;

        LCDPCTL1 = 0xff0f;

        LCDPCTL2 = 0x0000;

        LCDCSSEL0 = 0x0f00;

        LCDCSSEL1 = 0x0000;

        LCDCSSEL2 = 0x0000;

        LCDM4 = 0x21; // common pins

        LCDM5 = 0x84;

        LCDCTL0 |= LCDON; //LCD_E module on

}

void lcd_put_temp (uint16_t n)

{

        uint8_t digits [4];

        /* separate number into digits */

        for (uint8_t i = 3; i > 0; i--){

                digits[i] = n % 10;

                n /= 10;

        }

        digits[0] = n % 10;

        lcd_mem_clr();

        LCDM4 = 0x21; // common pins

        LCDM5 = 0x84;

        LCDM8 = 0x80; // degree symbol

        /* least significant digit */

        LCDM9 = lcd_segment_map[digits[3]]&0x07;

        LCDM13 = (lcd_segment_map[digits[3]]&0xf0) >> 4;

        LCDM14 = lcd_segment_map[digits[2]]|0x08;

        LCDM15 = lcd_segment_map[digits[1]]&0xf7;

        /* most significant digit */

        LCDM12 = lcd_segment_map[digits[0]]&0xf0;

        LCDM13 |= (lcd_segment_map[digits[0]]&0x07) << 4;

}

void main (void)

{

        /* use VLO as MCLK and SMCLK source,

         * use REFO as ACLK */

        CSCTL4 = (SELA | SELMS0 | SELMS1);

        /* FLL reference is REFOCLK */

        CSCTL3 = (SELREF0);

        lcd_init();

        pm5_unlock();

        while (1){

                lcd_put_temp(1234);

                for (uint16_t i = 0; i < 0xfff; i++);

        }

}