does anyone have multiple i2c buses working? (!)

[bobsalterego]

folks,
after a week's worth of writing and rewriting code for multiple i2c buses, it still is a no go. i've simplified to no end and all to no avail. the first #use i2c(...) encountered by the compiler is used *forever*. despite many different ways of implementing the code, the first directive used is the only one used. to date i have tried compiler versions 3.068, 3.073, and 3.074. tech support at ccs says the same thing the manual does, "the last #use i2c(...) encountered is applied to any following i2c functions".

some excerpts to form an example,

#device PIC16C65B

#define PIN_B6 54 /* local i2c devices */
#define SCTLCLK 54
#define PIN_B7 55
#define SCTLDAT 55

#define PIN_C1 57 /* i2c devices on backplane segment B */
#define BKPLBCLK 57
#define PIN_C2 58
#define BKPLBDAT 58

#define PIN_C3 59 /* i2c devices on backplane segment A */
#define BKPLACLK 59
#define PIN_C4 60
#define BKPLADAT 60

#use i2c(master,sda=SCTLDAT,scl=SCTLCLK)
[code here using i2c, PART A]
#use i2c(master,sda=BKPLADAT,scl=BKPLACLK)
[code here using i2c, PART B]
#use i2c(master,sda=BKPLBDAT,scl=BKPLBCLK)
[code here using i2c, PART C]

well, the code in PART A works correction; then ALL of the i2c commands in PARTS B and C result in wiggling of the SCTLDAT and SCTLCLK pins. the correct addresses and commands are sent, albeit on the wrong pair of pins. if i reorder the parts, again the first bus designated is utilized forever.

hence my questions: does anyone have multiple i2c buses working? what version of compiler are you using? care to share some ideas or code?

thanks,
bob


___________________________
This message was ported from CCS's old forum
Original Post ID: 2643

[Andrew Wilson Jones]

Hi Bob,
I have used the code below to produce an Eeprom (24LC65) copier. I can read the master chip and the program and verify the copy chip. I am using PCB version 2.632 During the program I just call:-
write_eeprom_byte()
read_eeprom_byte()
read_master_eeprom_byte()
as needed.

Andy


#define EEPROM_I2C_WRITE_ADDR 0xA0
#define EEPROM_I2C_READ_ADDR 0xA1

//--------------------------------------------------------------
// The First I2C functions
//--------------------------------------------------------------
#use i2c(Master, SDA=PIN_B7, SCL=PIN_B6, FAST)
//--------------------------------------------------------------
void write_eeprom_byte(long addr, char data)
{
i2c_start();
i2c_write(EEPROM_I2C_WRITE_ADDR);
i2c_write((char)(addr >> 8));
i2c_write((char)addr);
i2c_write(data);
i2c_stop();
delay_ms(6); // Wait enough time for the write to occur
}

//--------------------------------------------------------------
char read_eeprom_byte(long addr)
{
char data;
i2c_start();
i2c_write(EEPROM_I2C_WRITE_ADDR);
i2c_write((char)(addr >> 8));
i2c_write((char)addr);
i2c_start();
i2c_write(EEPROM_I2C_READ_ADDR);
data = i2c_read(0);
i2c_stop();
return(data);
}
//--------------------------------------------------------------
// The second I2C functions
//--------------------------------------------------------------
#use i2c(Master, SDA=PIN_A1, SCL=PIN_A0, FAST)
//--------------------------------------------------------------
char read_master_eeprom_byte(long addr)
{
char data;
i2c_start();
i2c_write(EEPROM_I2C_WRITE_ADDR);
i2c_write((char)(addr >> 8));
i2c_write((char)addr);
i2c_start();
i2c_write(EEPROM_I2C_READ_ADDR);
data = i2c_read(0);
i2c_stop();
return(data);
}
//--------------------------------------------------------------
// end of program
//--------------------------------------------------------------
//++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

___________________________
This message was ported from CCS's old forum
Original Post ID: 2655