Part Number: TMS320F28379D
Tool/software: Code Composer Studio
Hi. I am trying to communicate with magnetometer through I2C. I learned how to initialize I2C peripheral and some I2C standard functions used in example i2c_ex2_eeprom.c and i2c_ex1_loopback.c. Now I try to make my own I2C functions based on those examples to build up my sensor library. As I saw in example, to read and write to I2C, we follow this procedure (assumed all initializations have been done):
To write to I2C:
- set slave address
- set register address to be written
- put data ready to be sent
- send start condition
- send stop condition
To read I2C
- set slave address
- set register address to be read
- send start condition
- wait for I2C_INTSRC_REG_ACCESS_RDY to be triggered and then, send stop condition inside ISR
- set number of bytes to be read
- read data using I2C_getData()
I follow this procedure and make some function as shown below. But I have some problem with read function ( write function seemed to be ok)
- I2C_INTSRC_REG_ACCESS_RDY was not triggered so stop condition could not be sent to end the setting up address process
- the program stuck in while(I2C_getStopConditionStatus(base)!=0). But it stuck in the second statement not the first one which I found weird since stop condition cant be sent inside ISR
Please give me some advice. Thanks in advance
void initI2C(uint32_t base)
{
I2C_disableModule(base);
// I2C configuration. Use a 400KHz I2C clock with a 33% duty cycle
I2C_initMaster(base, DEVICE_SYSCLK_FREQ, 400000, I2C_DUTYCYCLE_33);
I2C_setBitCount(base, I2C_BITCOUNT_8);
// I2C_setSlaveAddress(base, slaveAddr);
I2C_setEmulationMode(base,I2C_EMULATION_FREE_RUN);
// enable stop condition and register-access-ready interrupts
I2C_enableInterrupt(base,I2C_INT_STOP_CONDITION |
I2C_INT_REG_ACCESS_RDY);
// FIFO configuration
I2C_enableFIFO(base);
I2C_clearInterruptStatus(base,I2C_INT_RXFF | I2C_INT_TXFF);
I2C_enableModule(base);
}
int16_t i2cRead(uint32_t base, uint16_t slaveAddr,uint16_t regAddr,uint16_t *data,uint16_t data_length)
{
uint16_t count;
if(I2C_getStopConditionStatus(base))
{
return ERROR_STOP_NOT_READY;
}
I2C_setSlaveAddress(base, slaveAddr);
I2C_setDataCount(base, 1);
I2C_putData(base, regAddr);
I2C_setConfig(base, I2C_MASTER_SEND_MODE);
I2C_sendStartCondition(base);
// I2C_sendStopCondition(base);
while(I2C_getStopConditionStatus(base)!=0);
I2C_setDataCount(base,data_length);
I2C_setConfig(base,I2C_MASTER_RECEIVE_MODE);
I2C_sendStartCondition(base);
I2C_sendStopCondition(base);
while(I2C_getStopConditionStatus(base)!=0); // this is where the program stuck
// while(data_ready_flag==0);
for(count=0;count<data_length;count++)
{
//while(I2C_getRxFIFOStatus(base)==I2C_FIFO_RXEMPTY);
*(data+count) = I2C_getData(base);
}
return SUCCESS;
}
int16_t i2cWrite(uint32_t base,uint16_t slaveAddr, uint16_t regAddr, uint16_t data)
{
if(I2C_getStopConditionStatus(base))
{
return ERROR_STOP_NOT_READY;
}
I2C_setSlaveAddress(base, slaveAddr);
if(I2C_isBusBusy(I2CB_BASE))
{
return(ERROR_BUS_BUSY);
}
I2C_setDataCount(base,2);
I2C_putData(base,regAddr);
I2C_putData(base, data);
I2C_setConfig(base,I2C_MASTER_SEND_MODE);
I2C_sendStartCondition(base);
I2C_sendStopCondition(base);
return SUCCESS;
}
int16_t i2cWriteMulti(uint32_t base,uint16_t slaveAddr, uint16_t regAddr, uint16_t *data,uint16_t data_length)
{
uint16_t i;
if(I2C_getStopConditionStatus(base))
{
return ERROR_STOP_NOT_READY;
}
I2C_setSlaveAddress(base, slaveAddr);
if(I2C_isBusBusy(I2CB_BASE))
{
return(ERROR_BUS_BUSY);
}
I2C_setDataCount(base,data_length+1);
I2C_putData(base,regAddr);
for(i=0; i<data_length;i++)
{
I2C_putData(base, *(data+i));
}
I2C_setConfig(base,I2C_MASTER_SEND_MODE);
I2C_sendStartCondition(base);
I2C_sendStopCondition(base);
return SUCCESS;
}
__interrupt void i2cISR()
{
count++;
intSource = I2C_getInterruptSource(I2CB_BASE);
switch(intSource)
{
case I2C_INTSRC_STOP_CONDITION:
{
}
break;
case I2C_INTSRC_REG_ACCESS_RDY:
{
if((I2C_getStatus(I2CB_BASE)&I2C_STS_NO_ACK)!=0)
{
I2C_sendStopCondition(I2CB_BASE);
I2C_clearStatus(I2CB_BASE, I2C_STS_NO_ACK);
}
}
break;
}
Interrupt_clearACKGroup(INTERRUPT_ACK_GROUP8);
}
