Starterware/PCF8575: PCF8575 not response

Hello Andres,
Do you have schematics for each version of the design? Also, have you captured I2C traffic? Please attach waveforms so I can verify commands and sequences.
-Francis Houde

Hello Francis ,

Thanks for you response , i am try work with the next schematic .

with this configuratoin the pcf8574 response and work fine ,but the pcf 8575 response all time 0xff  and the out stay in high .

the adrres of the device are :

#define PCF_8575 0x38 
#define PCF_8574 0x39 

the configurtion of the port is :

SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE);
SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C2);
SysCtlPeripheralReset(SYSCTL_PERIPH_I2C2);



GPIOPinConfigure(GPIO_PE4_I2C2SCL);
GPIOPinConfigure(GPIO_PE5_I2C2SDA );

GPIOPinTypeI2CSCL(GPIO_PORTE_BASE, GPIO_PIN_4);
GPIOPinTypeI2C(GPIO_PORTE_BASE, GPIO_PIN_5);
HWREG(I2C2_BASE + I2C_O_MCR) = I2C_MCR_MFE ;
I2CMasterInitExpClk(I2C2_BASE, SysCtlClockGet(), false);

 the function read of the data in the pcf 8575  is : 

int PCF_8575_portIn(void){

int dato;
int dato2;

I2CMasterSlaveAddrSet(I2C2_BASE,PCF_8575,true);

I2CMasterControl(I2C2_BASE, I2C_MASTER_CMD_BURST_RECEIVE_START );
while(I2CMasterBusy(I2C2_BASE))
{
}
dato=I2CMasterDataGet(I2C2_BASE);
I2CMasterControl (I2C2_BASE, I2C_MASTER_CMD_BURST_RECEIVE_FINISH);
while(I2CMasterBusy(I2C2_BASE))
{
}
dato2=I2CMasterDataGet(I2C2_BASE);

return dato2;
}

 and the function write of the data in the pcf 8575  is : 

void PCF_8575_PortOut(int data){

I2CMasterSlaveAddrSet(I2C2_BASE,PCF_8575 , false);
I2CMasterDataPut(I2C2_BASE, 0xff);
I2CMasterControl(I2C2_BASE, I2C_MASTER_CMD_BURST_SEND_START);
while(I2CMasterBusy(I2C2_BASE));
I2CMasterDataPut(I2C2_BASE, 0x00);
I2CMasterControl(I2C2_BASE, I2C_MASTER_CMD_BURST_SEND_FINISH);
while(I2CMasterBusy(I2C2_BASE));

Thanks for your help .

in the past post i put the output pin in constant values only for test ,, but he output not response .

Hello Andres,

I am wondering if you are using the correct address?  I see you have the following:

#define PCF_8575 0x38 
#define PCF_8574 0x39 

I am looking at the pins and the available address and it doesn't seem to match the datasheets

I would like to see waveforms capturing I2C transactions to make sure it matches what your code is trying to do.

-Francis Houde

hello Francis , Thanks for your answer.

the address it is ok , in these two IC expander , the numeber its for 7 bits configuration without read/writte bit , example 0X38 => 0b0111000X x=1 read and x=0 Writte .