Posted on May 25, 2006 at 01:30Could some experts in this forum kindly
take a look at my I2C routines below.
The problems are:
config_I2C1() ..... not sure if this correct
write_I2C_configuration_PCA9555() ..... write the wrong value !!!
read_I2C_PCA9555() ..... my system hang as soon as the
function is called !!!
Here is the code:
////////////////////////////////////////////////////////////////////////
void config_I2C1(void)
{
GPIO_Config(GPIO0, I2C_SCL|I2C_SDA, GPIO_AF_OD); //Open-drain output for SCL (P0.2), SDA (P0.3)
I2C_Init(I2C1); //Initialize I2C1
I2C_FCLKConfig(I2C1); //Config I2C freq. according for FCLK freq.
I2C_OnOffConfig(I2C1, ENABLE); //Enable I2C Peripheral
I2C_SpeedConfig(I2C1,90000); //Select I2C Clock speed = 100khz
I2C_AcknowledgeConfig(I2C1, ENABLE); //Enable Acknowledge feature
}
///======================================================//
void write_I2C_configuration_PCA9555(void) // Set both PORTS as INPUT --- Send 4-bytes
{
I2C_STARTGenerate(I2C1, ENABLE); //start condition
while (I2C_FlagStatus (I2C1,DIRECT,I2C_SB) == RESET); //Check Start bit Flag
I2C_AddressSend(I2C1, 0x40, I2C_Mode7, I2C_TX); //Send PCA9555 ADX Write = 0x40
while (I2C_FlagStatus (I2C1,DIRECT,I2C_ENDAD) == RESET); //Check End-of-address xmit
I2C_FlagClear(I2C1, I2C_ENDAD); //Clear Flag
I2C_ByteSend(I2C1, 0x06); //Send CMD 0x06 -- Port Configuration
while (I2C_FlagStatus (I2C1,DIRECT,I2C_BTF) == RESET); //Check byte-transfer-finish flag
I2C_ByteSend(I2C1, 0xff); //Send 0xff -- Set Port0 as Input
while (I2C_FlagStatus (I2C1,DIRECT,I2C_BTF) == RESET); //Check byte-transfer-finish flag
I2C_ByteSend(I2C1, 0xff); //Send 0xff --Set Port1 as Input
while (I2C_FlagStatus (I2C1,DIRECT,I2C_BTF) == RESET); //Check byte-transfer-finish flag
I2C_STOPGenerate(I2C1,ENABLE); //Stop Condition
}
////=====================================================//
void read_I2C_PCA9555(void)
{
I2C_STARTGenerate(I2C1, ENABLE); //start condition
while (I2C_FlagStatus (I2C1,DIRECT,I2C_SB) == RESET);
I2C_AddressSend(I2C1, 0x40, I2C_Mode7, I2C_TX); //Send PCA9555 ADX Write = 0x40
while (I2C_FlagStatus (I2C1,DIRECT,I2C_ENDAD) == RESET);
I2C_FlagClear(I2C1, I2C_ENDAD);
I2C_ByteSend(I2C1, 0x00); //Send CMD 0x00 -- Port0 Input Register
while (I2C_FlagStatus (I2C1,DIRECT,I2C_BTF) == RESET);
I2C_STARTGenerate(I2C1, ENABLE); //Re-start condition
while (I2C_FlagStatus (I2C1,DIRECT,I2C_SB) == RESET);
I2C_AddressSend(I2C1, 0x41, I2C_Mode7, I2C_RX); //Send PCA9555 ADX Read = 0x41
while (I2C_FlagStatus (I2C1,DIRECT,I2C_ENDAD) == RESET);
I2C_FlagClear(I2C1, I2C_ENDAD);
PCA9555_port0 = I2C_ByteReceive(I2C1); //Receive 1st Byte (Port0 of PCA9555)
PCA9555_port1 = I2C_ByteReceive(I2C1); //Receive 2nd Byte (Port1 of PCA9555)
I2C_AcknowledgeConfig(I2C1, DISABLE); //none-ACK
I2C_STOPGenerate(I2C1,ENABLE); //Stop Condition
///========================================================//
