Sensor cannot display on LCD

[ober]

Try out the simplest program which you are sure it is working with LCD.

From there, slowly add in more function and verify every time you add in a function to minimize the scope you need to debug. As Allen pointed out, get back the code you confirm it works with LCD, from there, add in function and always verify the small portion of code you add it.

[Lam]

I tried before of my previous coding, it works fine. I'm tried many many and many times to troubleshoot it! But still remain the same.... I'm solder and wrapping everything by my own.

Previous code display on LCD:

CODE: SELECT_ALL_CODE

#include <stdio.h>
#include <avr/io.h>
#include <util/delay.h>

#define LCD_CPRT   PORTC
#define LCD_CDDR   DDRC
#define LCD_CPIN   PINC
#define LCD_APRT   PORTA
#define LCD_ADDR   DDRA
#define LCD_APIN   PINA
#define LCD_RS      5
#define LCD_RW      6
#define LCD_EN      7

void delay_us(unsigned int d)
{
   _delay_us(d);
}

void delay_ms(unsigned int d)
{
   _delay_ms(d);
}

void enable_pulse(void)
{
   LCD_APRT |= (1<<LCD_EN);
   delay_us(1);
   LCD_APRT &= ~(1<<LCD_EN);
   delay_us(100);
}

void lcdCommand(unsigned char cmnd)
{
   delay_us(100);
   LCD_CPRT = cmnd;
   LCD_APRT &= ~(1<<LCD_RS);
   LCD_APRT &= ~(1<<LCD_RW);
   enable_pulse();
}

void lcdData(unsigned char data)
{
   delay_us(100);
   LCD_CPRT = data;
   LCD_APRT |= (1<<LCD_RS);
   LCD_APRT &= ~(1<<LCD_RW);
   enable_pulse();
}

void lcd_init()
{
   delay_us(100);
   LCD_CDDR = 0xFF;
   LCD_ADDR = 0xFF;
   
   delay_us(2000);
   lcdCommand(0x38);
   lcdCommand(0x0C);
   lcdCommand(0x06);
   delay_us(2000);
   lcdCommand(0x01);
   delay_us(1000);
}

void lcd_gotoxy(unsigned char x, unsigned char y)
{
   unsigned char firstCharAdr[] = {0x80,0xC0,0x94,0xD4};
   lcdCommand(firstCharAdr[y-1] + x - 1);
   delay_us(100);
}

void lcd_print(char *str)
{
   unsigned char i=0;
   while(str[i]!=0)
   {
      lcdData(str[i]);
      i++;
   }
}

int main(void)
{
   lcd_init();
   lcd_gotoxy(1,1);
   lcd_print("   Hello World  ");
   lcd_gotoxy(1,2);
   lcd_print("Nice to meet you");
   
   while(1);
   return 0;
}


[ABSF]

I compared the LCD sub-routines between your current project and the old project and found out the differences are in the delay_us() and delay_ms(). I dont know why you removed some of the delays in your current program. But may be that's the reason why the LCD display doesn't work.

LCDs are very slow devices and cannot cope with the high speed of the mcu. That's why a lot of delays were inserted in the sub-routines. Do put back all the missing delays and try to double the duration and see if it works. E.G. change delay_us(2000) to delay_us(4000), giving them plenty of tiem to do their job.

Allen

[yonghui]

i think escpecially the reset and clr screen command to lcd needs more delays. else lcd wont be able to display properly.

[Lam]

Thanks to everyone given a big advice to me!!!
My LCD finally display sensor's values under base decimal.

Solutions:
I'm used previously coding that's display my name, works!
Then I tried delete some characters, testing it 1 by 1 by deleted 1 by 1 coding, until last display 1 row of characters(such as "Hello").
Next, add on some ADC settings such as ADMUX ,ADCSRA and so on, display on LEDs, then display on LCD.
Surprising, it finally works clearly!
I don't know how to explain here, it's amazing and used me for 3weeks period!

My solution was solved, next I will proceed to display real temperature, humidity values...
Thanks to all of you very very much! ^^

[yonghui]

hi ,

great to hear that. and great effort to debug ur problem!

[ABSF]

So at least to-night you can have a sound sleep without dreaming your problem again.

Hope you've gain some experience on how to trouble-shoot your mcu project.

Allen

[robosang]

Good to hear that, but I guess most possible is the bug pointed by Allen Delay.

[Lam]

Perhaps Allen was right.
I'm very appreciate for all helps from you all!
Next I will proceed to Zigbee module. In case I face problem again, I hope you guys can guide me.

[robosang]

Hope to see some photos of your project, I feel satisfy when see what Malaysian can do, it make me proud !