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Need C code of I2C bus for LPC2138

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ramasamy

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Hello
I need C code of I2C bus for LPC2138
 

SphinX

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owen mooney i2c

Salam,

Code:
/*
  i2c support for LPC21XX

  (c) 2004  Yuri Tiomkin (yuri@tnkernel.com)


  Includes drivers:

   - EEPROM 24XX series (from 24XX04 to 24XX512)
   - Real Time Clock DS1307
   - I/O Extender PCA9555
   - Temperature sensor LM75

  Supports uCOS-II and TNKernel

THIS SOFTWARE IS PROVIDED BY THE YURI TIOMKIN AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL YURI TIOMKIN OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.

*/
 
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SphinX

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i2conclr

Another I2C Code

Code:
/* This is a modified I2C module based on the code by Pierre Seguin		    */
/* it tests the status of all transactions and returns any error codes      */
/* via a "longjmp"                                                          */
/* It is easily modified to directly return the status codes instead of     */
/* using the longjmps                                                       */
/* This code returns an error value of 1 for the most likley error:-        */
/*  - no device available. This is not a code that can be confused with the */
/* standard status values.                                                  */
/* A sample of its use is getBattery() using a PCF8591 A/D device           */
/* Owen Mooney                                                              */

jmp_buf i2cerror;

#define STA  0x20
#define SIC  0x08
#define SI   0x08
#define STO  0x10
#define STAC 0x20
#define AA   0x04

void InitI2C(void) {
	I2CONCLR = 0xFF;
	PINSEL0  |= 0x50;   //  Set pinouts as scl and sda
   I2SCLL   =19;	     //speed at 100Khz for a VPB Clock Divider  = 4 at 14 MHz
   I2SCLH   =19;
	// I2SCLL=60;	     //speed at 375Khz for a VPB Clock Divider  = 1
	// I2SCLH=70;       // Pierre Seguin's origional values.
	I2CONSET = 0x40;    //Active Master Mode on I2C bus
}

void SendI2CAddress(unsigned char Addr_S){
    unsigned char r;
    I2CONCLR = 0xFF;             // clear I2C - included if User forgot to "StopI2C()"
                                 // else this function would hang.
    I2CONSET = 0x40;             // Active Master Mode on I2C bus
    if((Addr_S & 0x01))          // test if it's reading
       I2CONSET = STA | AA;      // set STA - allow master to acknowlege slave;
    else
       I2CONSET = STA;           // set STA dont allow acknowledges;
    while(I2STAT!=0x08) ;        // Wait for start to be completed
    I2DAT    = Addr_S;           // Charge slave Address
    I2CONCLR = SIC | STAC;       // Clear i2c interrupt bit to send the data
    while( ! ( I2CONSET & SI)) ; // wait till status available
    r=I2STAT;                    // read Status. See standard error codes pdf (link in manual).
    if(!(Addr_S & 0x01)) {       // if we are doing a write
        if (r != 0x18) {             // look for "SLA+W has been transmitted; ACK has been received"
             if ( r==0x20 )          // check for "SLA+W has been transmitted; NOT ACK has been received"
                longjmp(i2cerror,1); // no acknowlege - probably no device there. Return a 1 in longjmp
             longjmp(i2cerror,r);    // other error - return status code in longjmp
        }
     } else {
        if (r != 0x40) {             // look for "SLA+R has been transmitted; ACK has been received"
             if ( r==0x48 )          // check for "SLA+R has been transmitted; NOT ACK has been received"
                longjmp(i2cerror,1); // no acknowlege - probably no device there. Return a 1 in longjmp
             longjmp(i2cerror,r);    // other error - return status code in longjmp
        }
     }
}

unsigned char ReadI2C(void) {
    unsigned char r;
    I2CONCLR = SIC;                  // clear SIC;
    while( ! (I2CONSET & 0x8));      // wait till status available
    r=I2STAT;                        // check for error
    if (r != 0x50){                  // look for "Data byte has been received; ACK has been returned"
       longjmp(i2cerror,r);          // read fail
    }
    return I2DAT;
}

void WriteI2C(unsigned char Data) {
    unsigned char r;
    I2DAT    = Data;                // Charge Data
    I2CONCLR = 0x8;                 // SIC; Clear i2c interrupt bit to send the data
    while( ! (I2CONSET & 0x8));     // wait till status available
    r=I2STAT;
    if (r != 0x28){                 // look for "Data byte in S1DAT has been transmitted; ACK has been received"
       longjmp(i2cerror,r);         // write fail
    }
}

void StopI2C(void){
    I2CONCLR = SIC;
    I2CONSET = STO;
    while((I2CONSET&STO)) ;         // wait for Stopped bus I2C
}

float getBattery(void){     // Read the battery voltage with a PCF8591 A/D device
   unsigned char err,r;
   char mess[10];
   int x;
   InitI2C();
   if (err=setjmp(i2cerror)) {
       if (err==1)
          error("no A/D device found");
       else
          sprintf(mess,"I2C error %d",err);
          error(mess);
       return;
   }
   SendI2CAddress(0x90);    // PCF8591 A/D device address
   WriteI2C(0);             // Set the control port value
   WriteI2C(0);             // and the D/A output
   StopI2C();
   SendI2CAddress(0x91);    // Start the read
   ReadI2C();               // dummy read cycle to do the first conversion
   r=ReadI2C();             // read the result
   StopI2C();
   return r*12.15/118;      // return the battery voltage
}
 

mystery

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yuri tiomkin

I used the LPC2148 and 8 PCA9555 using this code. Everything nice except StopI2C function. It needs to change, on the hand sometimes it waits forever.

void StopI2C(void){
I20CONSET = STO;
I20CONCLR = SIC;
while((I20CONSET&STO)) ;// wait for Stopped bus I2C
}
 

icekvot

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readi2c lm75

HELP. I have error: Temperat.c(4): error: #20: identifier "jmp_buf" is undefined

(Keil mVision 3)

Added after 6 minutes:

Ohh lol ))) I have corrected a mistake.

I should connect library : setjmp.h
 

icekvot

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keil i2c interrupt 100khz

I have error :i2c error 0, what can it be?
 

sivasujith

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Re: LPC2138I2C

Some of your I2C Slave Transmitters...needs to recieve NOT ACK to stop transmitting... check that......


;)
 
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bobcat1

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Re: LPC2138I2C

Hi

The best solution is to use the LPC2138 hardware I2C interface best on interrupt's

There are many source code files on the net search using Google for "LPC21 & I2C)

All the best

Bobi

The microcontroller specialist
 

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