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Hi,
I'm trying here to communicate with the builtin EEPROM on the concerto experimenter kit but it seems that the I2C0_Master peripheral prefers to not load the data and then just hangs busy for ever.
I'm setting up the I2C controller as per example:
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOB);
SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C0);
GPIOPinConfigure(GPIO_PB6_I2C0SDA);
GPIOPinConfigure(GPIO_PB7_I2C0SCL);
GPIOPinTypeI2C(GPIO_PORTB_BASE, GPIO_PIN_6 | GPIO_PIN_7);
I2CMasterInitExpClk(I2C0_MASTER_BASE, SysCtlClockGet(SYSTEM_CLOCK_SPEED), false);
and then trying to run a very simple code, just for testing purposes for now:
void I2CWriteTest(void) {
i2cCurrentAddress = I2C_SLV_ADDR_EEPROM; // Get the EEPROM address from the #defines
unsigned char put = 'a'; // random char just to write something
I2CMasterSlaveAddrSet(I2C0_MASTER_BASE, i2cCurrentAddress, I2C_WRITE);
I2CMasterDataPut(I2C0_MASTER_BASE, put);
I2CMasterControl(I2C0_MASTER_BASE, I2C_MASTER_CMD_SINGLE_SEND);
UARTprintf(UART_DEBUG, "checkpoint1"); // Post on the UART0
while (I2CMasterBusy(I2C0_MASTER_BASE)) {} // wait for the controller to finish
UARTprintf(UART_DEBUG, "checkpoint2"); // Post on the UART0
}
This code always pass through checkpoint1, but never checkpoint2.
While debugging and I press Pause, I can see the processor is locked inside the while.
I2C_SLV_ADDR_EEPROM is 0x50 or b1010000 (as per manual address is _1_0_1_0_A2_A1_A0_RW) and the Experimenter drawing shows as all to GND.
Analysing the registries when pausing the code I can see I2CMSA = 0x000000A0 meaning that I2CMasterSlaveAddrSet correctly set the 0x50 and added the I2C_WRITE bit at the end of it.
Also on the registries and moving the software step by step using F6 I can see that I2CMDR is always = 0x00000000, even thou I put an 'a' in there.
Is my EEPROM addressing wrong? Is the code wrong? What am I missing?
Thanks!
I have reviewed the loopback example for I2C as well as tried to implement Ronaldo's code above. The difference in my case is that I must use the M3 alternate port F for the I2C clock and data. I cannot get the proper output signals. In my case, I am trying to read the 6 byte MAC address from an Atmel AT24MAC402. The part requires an address of 0xb in the upper half of the byte and I have set my device address to 3 using jumpers. So my device address byte should appear as 0xb6. The memory location at which I need to begin reading in the device is 0x9a.
Note, the 0xb differs from the normal I2C start code of 0xa. Ronaldo used 0x50, I believe, and I don't understand whyhe used that value. Perhaps therein lies my own misunderstanding the key to my problem?
Is there an issue with the M3 Alternate registers? Is there more setup involved?
Thanks for any help.
Pat
Here is my code:
Initialization
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);
SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C0);
// configure EEPROM (I2C on PF0,1)
GPIOPinConfigure(GPIO_PF0_I2C0SDA);
GPIOPinConfigure(GPIO_PF1_I2C0SCL);
GPIOPinTypeI2C(GPIO_PORTF_BASE, GPIO_PIN_0 | GPIO_PIN_1);
Service:
// write device EUI address to EEPROM
I2CMasterSlaveAddrSet(I2C0_MASTER_BASE, 0xb6, false);
// Place the word address data to be sent in the data register
I2CMasterDataPut(I2C0_MASTER_BASE, 0x9a); //&ulDataTx[0]);
// Initiate send of data from the master.
I2CMasterControl(I2C0_MASTER_BASE, I2C_MASTER_CMD_BURST_SEND_START); //SINGLE_SEND);
while (I2CMasterBusy(I2C0_MASTER_BASE)){}
// Place the word address data to be sent in the data register
I2CMasterDataPut(I2C0_MASTER_BASE, 0x9a); //&ulDataTx[0]);
// Initiate send of data from the master.
I2CMasterControl(I2C0_MASTER_BASE, I2C_MASTER_CMD_BURST_SEND_CONT); //SINGLE_SEND);
while (I2CMasterBusy(I2C0_MASTER_BASE)){}
// initiate read process
I2CMasterSlaveAddrSet(I2C0_MASTER_BASE, 0xb6, true);
// Send data from the master to the slave.
for(ulindex = 0; ulindex < 6; ulindex++)
{
switch (ulindex)
{
case 0:
// Initiate send of data from the master.
I2CMasterControl(I2C0_MASTER_BASE, I2C_MASTER_CMD_BURST_RECEIVE_START);
break;
case 5:
I2CMasterControl(I2C0_MASTER_BASE, I2C_MASTER_CMD_BURST_RECEIVE_FINISH);
break;
// Read the data from the slave.
default:
I2CMasterControl(I2C0_MASTER_BASE, I2C_MASTER_CMD_BURST_RECEIVE_CONT);
break;
}
// Wait until master module is done transferring.
while(I2CMasterBusy(I2C0_MASTER_BASE)){}
ulDataRx[ulindex] = I2CMasterDataGet(I2C0_MASTER_BASE);
}
//////////
Below are two waveforms, first of the entire sequence, second to show detail of the first few bytes.
