l3g4200d

[hamid9543]

hi
i write  code l3g4200d

Code:

#Include <16f873a.h> 
#use delay (clock = 20000000)
#Use I2C (master, sda = PIN_C3, scl = PIN_C4)
#define LCD_RS_PIN      PIN_b1                                    ////
#define LCD_RW_PIN      PIN_b2                                    ////
#define LCD_ENABLE_PIN  PIN_b3                                    ////
#define LCD_DATA4       PIN_b4                                    ////
#define LCD_DATA5       PIN_b5                                    ////
#define LCD_DATA6       PIN_b6                                    ////
#define LCD_DATA7       PIN_b7 
#define CTRL_REG1 0x20
#define CTRL_REG2 0x21
#define CTRL_REG3 0x22
#define CTRL_REG4 0x23
#define CTRL_REG5 0x24
#include <LCD.c>
int L3G4200D_Address = 0xD2;   //I2C address of the L3G4200D
int x,y,z;
void writeRegister(int deviceAddress, int address,int val)
 {
    i2c_start();
    i2c_write(deviceAddress); // start transmission to device 
    i2c_write(address);       // send register address
    i2c_write(val);           // send value to write
    i2c_stop();               // end transmission
 }

void setupL3G4200D(int scale)
{
  writeRegister(L3G4200D_Address, CTRL_REG3, 0b00001000);
  if(scale == 250)
  {
  writeRegister(L3G4200D_Address, CTRL_REG4, 0b00000000);
  }
  else if(scale == 500)
  {
  writeRegister(L3G4200D_Address, CTRL_REG4, 0b00010000);
  }
  else
  {
  writeRegister(L3G4200D_Address, CTRL_REG4, 0b00110000);
  }
}

void main()
{
lcd_init();
lcd_gotoxy(1,1);
printf(lcd_putc,"starting up L3G4200D");
delay_ms (1000);
setupL3G4200D(2000);            //Configure L3G4200  - 250, 500 or 2000 deg/sec
writeRegister(L3G4200D_Address,0x20,0x0F);
delay_ms(1500);                 //wait for the sensor to be ready 

while(true)
{
    i2c_start();
    i2c_write(L3G4200D_Address);
    i2c_write(0xD3);
    i2c_start();
    int xLSB=i2c_read(0x28);  // register to read
    int xHSB=i2c_read(0x29);  // register to read
    x = make16(xHSB,xLSB);
    int yLSB=i2c_read(0x2A);  
    int yHSB=i2c_read(0x2B);
    y = make16(yHSB,yLSB);
    int zLSB=i2c_read(0x2C);  
    int zHSB=i2c_read(0x2D);
    z = make16(zHSB,zLSB);
    i2c_stop();              //This will update x, y, and z with new values
  lcd_gotoxy(1,2);  
  printf(lcd_putc,"x=%03u",x);
  lcd_gotoxy(6,1);
  printf(lcd_putc,"y=%03u",y);
  lcd_gotoxy(12,1);
  printf(lcd_putc,"z=%03u",z);
  delay_ms(100); 
}
}

but lcd  show x=-1   y=-1    z=-1
can you help me?

[robotai]

The code you used to read I2C seems not correct.
Maybe refer to datasheet in below link
http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00265057.pdf
On P22~23 has correct command tables. Especially Table 17.

Part of your code may look like

Code:

while(true)
{
    i2c_start();
    i2c_write(L3G4200D_Address);  // write first
    i2c_write(0x28);  // set register to start read
    i2c_start();
    i2c_write(L3G4200D_Address+1);  // start read then
    int xLSB=i2c_read();  // read register in sequence
    int xHSB=i2c_read();
    x = make16(xHSB,xLSB);
    int yLSB=i2c_read();  
    int yHSB=i2c_read();
    y = make16(yHSB,yLSB);
    int zLSB=i2c_read();  
    int zHSB=i2c_read();
    z = make16(zHSB,zLSB);
    i2c_stop();              //This will update x, y, and z with new values
  lcd_gotoxy(1,2);  
  printf(lcd_putc,"x=%03u",x);
  lcd_gotoxy(6,1);
  printf(lcd_putc,"y=%03u",y);
  lcd_gotoxy(12,1);
  printf(lcd_putc,"z=%03u",z);
  delay_ms(100); 
}

[hamid9543]

i chang code and write new code

Code:

#Include <16f873a.h> 
#use delay(xtal=20Mhz)
#fuses NOWDT,HS
#use i2c(Master,sda=PIN_c4,scl=PIN_c3)
#define LCD_RS_PIN      PIN_b1                                    
#define LCD_RW_PIN      PIN_b2 
#define LCD_ENABLE_PIN  PIN_b3                                    
#define LCD_DATA4       PIN_b4                                    
#define LCD_DATA5       PIN_b5                                    
#define LCD_DATA6       PIN_b6                                    
#define LCD_DATA7       PIN_b7 
#include <LCD.c>
#define gyro_ADD_R 0xD3
#define gyro_ADD_W 0xD2
#define CTRL_REG1 0x20
#define CTRL_REG2 0x21
#define CTRL_REG3 0x22
#define CTRL_REG4 0x23
#define CTRL_REG5 0x24

int16 x=0;
int8 xM=0,xL=0;

void writeRegister(int8 reg,int8 value)
 {
    i2c_start();
    i2c_write(gyro_ADD_W);     
    i2c_write(reg);       
    i2c_write(value);           
    i2c_stop();              
 }



void init_gyro()
{
writeRegister(CTRL_REG1,0b00001111);
writeRegister(CTRL_REG2,0b00001000);
writeRegister(CTRL_REG3,0b00001000);
writeRegister(CTRL_REG4,0b10110000);
writeRegister(CTRL_REG5,0b00000000);
}

void main()
{
lcd_init();
lcd_gotoxy(1,1);
printf(lcd_putc,"starting up L3G4200D");
delay_ms(1000);
init_gyro();  

while(true)
{
    i2c_start();
    i2c_write(0XD2);             
    i2c_write(0x28); 
    i2c_start();
    i2c_write(0XD3);            
    xL=i2c_read();         
    xM=i2c_read();
    x=make16(xM,xL);
    i2c_stop();
    printf(lcd_putc"\f"); 
    lcd_gotoxy(1,2);  
    printf(lcd_putc,"x=%Ld",x);
    delay_ms(50); 
}

}

but lcd do not display fix value( x ) and this value changing very fast.
attention:scan i2c bus works corectly

[robotai]

Seems you made it worked. 

I suppose the value would change but should within some range. Maybe set CTRL_REG4 to lower dps may help.

[flo0319]

You read a new value and display it with a rate of 20 times / second , you can put a half second delay in main loop and you will can see "normal" changes

[hamid9543]

update code

Code:

while(true) 
{ 
    i2c_start(); 
    i2c_write(0XD2);              
    i2c_write(0x28); 
    i2c_start(); 
    i2c_write(0XD3);            
    xL=i2c_read();          
    xM=i2c_read(0); 
    x=make16(xM,xL); 
    i2c_stop(); 
    printf(lcd_putc"\f"); 
    lcd_gotoxy(1,2);  
    printf(lcd_putc,"x=%Lu",x); 
    delay_ms(1500); 
}

i do not any move l3g4200d but the value of lcd output is not fixed.

[flo0319]

It's normal to not be a fixed value.  You have set a high sensitivity and also the HP filter is disabled. Any variation in magnetic field from your environment will be present in sensor measurement 

Any data need to be filtered because noises.

you can change the REG4 for a lower dsp (ex. 0b10010000 for 500 scale)

but I recommend  you to use the high pass filter

[hamid9543]

update code,but not working......

[demure]

L3G4200D.h

Code:

/*

/*************************
    L3G4200D Registers
*************************/
#define gyro_WHO_AM_I 0x0F
#define gyro_CTRL_REG1 0x20
#define gyro_CTRL_REG2 0x21
#define gyro_CTRL_REG3 0x22
#define gyro_CTRL_REG4 0x23
#define gyro_CTRL_REG5 0x24
#define gyro_REFERENCE 0x25
#define gyro_OUT_TEMP 0x26
#define gyro_STATUS_REG 0x27
#define gyro_OUT_X_L 0x28
#define gyro_OUT_X_H 0x29
#define gyro_OUT_Y_L 0x2A
#define gyro_OUT_Y_H 0x2B
#define gyro_OUT_Z_L 0x2C
#define gyro_OUT_Z_H 0x2D
#define gyro_FIFO_CTRL_REG 0x2E
#define gyro_FIFO_SRC_REG 0x2F
#define gyro_INT1_CFG 0x30
#define gyro_INT1_SRC 0x31
#define gyro_INT1_TSH_XH 0x32
#define gyro_INT1_TSH_XL 0x33
#define gyro_INT1_TSH_YH 0x34
#define gyro_INT1_TSH_YL 0x35
#define gyro_INT1_TSH_ZH 0x36
#define gyro_INT1_TSH_ZL 0x37
#define gyro_INT1_DURATION 0x38

i2c rutine
you have to define address
#define  gyro_write_addr 0xD2
#define  gyro_read_addr  0xD3

[hamid9543]

hi
When the l3g4200d is fixed and do not move it out how it is.
thanx