software i2c not working..

[hitsumen]

Posted on March 09, 2012 at 16:41

Want to read my LIS302 sensor with software I2C (bit banging)

Hardware i2c works.Here is some code.Please help me with software i2c...

http://pastebin.com/d0M9jRaY

[emalund]

Posted on March 12, 2012 at 20:37

with software I2C (bit banging)

WHY?Here is some code.

http://pastebin.com/d0M9jRaY

I have no intention of accessing ''some strange site'' what is wrong with posting code here? Erik

[hitsumen]

Posted on March 13, 2012 at 15:37

static void I2C1_GPIO_Config(void)

{  GPIO_InitTypeDef  GPIO_InitStructure;   //GPIO_DeInit(GPIOB);    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);    // Configure I2C1 pins: SCL and SDA   GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_6 | GPIO_Pin_7;  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD;    GPIO_Init(GPIOB, &GPIO_InitStructure);  }void I2C_delay(void){    unsigned int i=150;    while(i)    {      i--;    } }bool I2C1_Start(void){ SDAH; SCLH; I2C_delay(); if(!SDAread)return FALSE;  SDAL; I2C_delay(); if(SDAread) return FALSE;  SDAL; I2C_delay(); return TRUE;}void I2C1_Stop(void){ SCLL; I2C_delay(); SDAL; I2C_delay(); SCLH; I2C_delay(); SDAH; I2C_delay();}void I2C1_Ack(void){  SCLL; I2C_delay(); SDAL; I2C_delay(); SCLH; I2C_delay(); SCLL; I2C_delay();}void I2C1_NoAck(void){  SCLL; I2C_delay(); SDAH; I2C_delay(); SCLH; I2C_delay(); SCLL; I2C_delay();}bool I2C1_WaitAck(void)   { SCLL; I2C_delay(); SDAH;    I2C_delay(); SCLH; I2C_delay(); if(SDAread) {          SCLL;          return FALSE; } SCLL; return TRUE;}void I2C1_SendByte(unsigned char SendByte) {    unsigned char i=8;    while(i--)    {        SCLL;        I2C_delay();        if(SendByte&0x80)          SDAH;          else         SDAL;           SendByte<<=1;        I2C_delay(); SCLH;        I2C_delay();    }    SCLL;}unsigned char I2C1_ReceiveByte(void)  {     unsigned char i=8;    unsigned char ReceiveByte=0;    SDAH;        while(i--)    {      ReceiveByte<<=1;            SCLL;      I2C_delay();      SCLH;      I2C_delay();       if(SDAread)      {        ReceiveByte|=0x01;      }    }    SCLL;    return ReceiveByte;} unsigned char I2C1_ReadByte( unsigned char DeviceAddress, int ReadAddress){      unsigned char temp;    if(!I2C1_Start())return FALSE;        I2C1_SendByte((DeviceAddress & 0xFE));     if(!I2C1_WaitAck()){I2C1_Stop(); return FALSE;}     I2C1_SendByte((unsigned char)((ReadAddress>>8) & 0xFF));         I2C1_WaitAck();    I2C1_SendByte((unsigned char)((ReadAddress) & 0xFF));             I2C1_WaitAck();    I2C1_Start();    I2C1_SendByte((DeviceAddress & 0xFE)|0x01);        I2C1_WaitAck();       temp = I2C1_ReceiveByte();        I2C1_NoAck();         I2C1_Stop();    return temp;}/************************************MAIN****************************/int main( void ){  prvSetupHardware();  I2C1_GPIO_Config();  initDisplay();  itoc(I2C1_ReadByte(I2C_ADDRESS, 0x0F));  GLCD_displayStringLn(Line3, string);}

[hitsumen]

Posted on March 13, 2012 at 16:58

ah.. Forget to mention this, you can ask if you need some more info..:

#define SCLH GPIOB->BSRR = GPIO_Pin_6 #define SCLL GPIOB->BRR = GPIO_Pin_6 #define SDAH GPIOB->BSRR = GPIO_Pin_7 #define SDAL GPIOB->BRR = GPIO_Pin_7

#define SCLread GPIOB->IDR & GPIO_Pin_6

#define SDAread GPIOB->IDR & GPIO_Pin_7

[emalund]

Posted on March 13, 2012 at 17:56

still no answer

WHY? Erik

[hitsumen]

Posted on March 13, 2012 at 19:43

For learning purposes.. I am student..

Later I need to launch the camera which uses SCCB bus (something like i2c but a bit different)..

[emalund]

Posted on March 13, 2012 at 20:11

1) is the device you access I²C or SMB (SMB has timeouits,I²C does not, otherwise they are, for all practical purposes identical.

2) you are using an arbitrary delay (all delays in C are, by definition, arbitrary) put a scope on SCL and verify it is OK Erik

[hitsumen]

Posted on March 15, 2012 at 09:32

1. Its I2C.

2. So the code is right? What do you mean arbitary?

[emalund]

Posted on March 15, 2012 at 16:47

arbitrary Timing loops in C:

there is no rule whatsoever for how a compiler implement a C construct. I recall an incident version x of a '51 compiler implemented for (time = 0; time !=47; time++) this way: mov r7,time loop: cjne r7, #47, continue ret continue: mov acc, r7 inc a mov r7,a sjmp loop then the compiler maker go smarter and in rev y it looked like this mov r7,#47 loop: djnz r7,loop ret and everybodys code with delays in C fell apart. The above is as best I recall and should be accurate. Erik

[emalund]

Posted on March 15, 2012 at 16:49

I guess your code, faulty or not, will generate a few SCL pulses, put a sope on SCL and make sure the timing is at or below what your external devices datasheet  specify

Erik