how can i develop a programme which control lcd?

Hello blackslave,

Do you mean a standard LCD (like 20x2)? If yes you can take the provided software examples which are included in the Nios package. Which Nios are you using?

Bye,

niosIIuser

Hi,

I've been busy with other software and haven't got back to playing with Nios II yet. When I was playing with Nios II, I was using uClinux and my main interest was in writing a device driver for a simple device. I built a very basic hello world device driver as a module and was able to insmod it into memory - my biggest hurdle was figuring out how to get the module to build, I wrote a thread which contained some instructions on how to build a module for a Nios II uClinux kernel. It's this thread here (http://www.niosforum.com/forum/index.php?act=st&f=17&t=93).

Once you've got a module that you can insmod it should be pretty straightforward to customize it for your lcd, a good starting point would be to look at the device driver for the buttons that exists in the drivers section of the kernel source - you'll also need a skeleton 2.6 module driver to put your code in, but there's only a few lines of code required for a basic driver so you should be able to find one very easily.

Adrian

It's, literally, as simple as....

FILE *lcd = fopen( "/dev/lcd_display", "w" );

fprintf( lcd, "Your message here....with formatting %s", some_string );

That being said, there are multiple examples of this in the software templates that are included with the kit.

Good luck,

slacker

i have tried a lot to find the 16*2 lcd driver in the core of uclinux (in the menuconfig).

but until now i can't find such a option.

if somebody knows how to add it to the core ,can you help me?

and i also tried to write a driver of it, but it didnt word well.

i'd like to share it to you , and i hope anybody can point what the problem is in the file.

#include <linux/module.h># include <linux/errno.h># include <linux/cdev.h># include <linux/config.h># include <linux/types.h># include <linux/errno.h># include <linux/miscdevice.h># include <linux/slab.h># include <linux/ioport.h># include <linux/fcntl.h># include <linux/mc146818rtc.h># include <linux/netdevice.h># include <linux/sched.h># include <linux/delay.h>

# include <asm/io.h># include <asm/uaccess.h># include <asm/system.h># include <linux/delay.h>

# define LCD_On 1# define LCD_Off 2# define LCD_Clear 3# define LCD_Reset 4# define LCD_Cursor_Left 5# define LCD_Cursor_Right 6# define LCD_Disp_Left 7# define LCD_Disp_Right 8# define LCD_Get_Cursor 9# define LCD_Set_Cursor 10# define LCD_Home 11# define LCD_Read 12# define LCD_Write 13# define LCD_Cursor_Off 14# define LCD_Cursor_On 15# define LCD_Get_Cursor_Pos 16# define LCD_Set_Cursor_Pos 17# define LCD_Blink_Off 18

# define kLCD_IR na_led_green# define kLCD_DR (na_led_green + 8)

# define LCDWriteData(x) outl(x , kLCD_DR)# define LCDWriteInst(x) outl(x , kLCD_IR)

# define LCDReadData inl(kLCD_DR)# define LCDReadInst inl(kLCD_IR)

# define Major 250

static int Device_Open = 0;

static int lcd_16207_ioctl(struct inode *inode,struct file *filp,

unsigned int cmd,unsigned long arg);

static int lcd_16207_open(struct inode *inode,struct file *filp)

{

static int counter = 0;

if(Device_Open)return -EBUSY;

Device_Open++;

printk("You have open the device %d times\n",counter++);

return 0;

}

static int lcd_16207_release(struct inode *inode,struct file *filp)

{

Device_Open--;

printk("You have release the device\n");

return 0;

}

static int lcd_16207_ioctl(struct inode *inode,struct file *filp,

unsigned int cmd,unsigned long arg)

{

volatile unsigned long display;

switch (cmd) {

case LCD_On:

if (copy_from_user

(&display, (unsigned long *) arg,

sizeof(display)))

return -EFAULT;

LCDWriteInst(display);

break;

case LCD_Off:

if (copy_from_user

(&display, (unsigned long *) arg,

sizeof(display)))

return -EFAULT;

LCDWriteData(display);

break;

default:

return -EINVAL;

}

return 0;

}

static struct file_operations lcd_16207_fops={

.ioctl = lcd_16207_ioctl,

.open = lcd_16207_open,

.release = lcd_16207_release,

};

static int lcd_16207_init(void)

{

int ret = register_chrdev(Major,"LCD_PIO",&lcd_16207_fops);

if(ret<0)

{

printk("Registering the device failed with %d\n",Major);

return Major;

}

printk("You have init Device %d\n",Major);

return 0;

}

static void lcd_16207_exit(void)

{

if(unregister_chrdev(Major,"LCD_PIO"))

printk("exit failed");

}

module_init(lcd_16207_init);

module_exit(lcd_16207_exit);

MODULE_AUTHOR("Andrew Bose");

MODULE_LICENSE("GPL");