CCS: failed to initialize I2C (EK-TM4C 123GXL)

I did not see anything obvious in the software. Have you checked your hardware? Do you have the pull-up resistors on SCL and SDA? What slave are you talking to? Is 0x69 the correct address? Do you see proper I2C signals when you look at SDA and SCL with a scope? Do you get an acknowledge from the slave.

Now it works. Seems like there was more than one error.
Besides using "analog" pullup-resistors, i changed the code a bit.
-->Getting the right signals with scope as with logic analizer.
/*
* main.c
*/
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "inc/hw_gpio.h"
#include "inc/hw_ints.h"
//#include "inc/hw_i2c.h" // not used?
//#include "inc/hw_sysctl.h" // not used?
//#include "inc/hw_types.h" // not used?
#include "driverlib/gpio.h"
//#include "driverlib/interrupt.h" // not used?
#include "driverlib/sysctl.h"
#include "driverlib/pwm.h"
#include "driverlib/pin_map.h"
#include "driverlib/uart.h"
#include "driverlib/i2c.h"
#include "utils/uartstdio.h"
#include "elmarlib/common.h"
#include "elmarlib/eeprom.h"
#include "elmarlib/misc.h"
#include "elmarlib/tof.h"
#include "elmarlib/lcd.h"
#include "sensorlib/hw_mpu9150.h"


uint32_t I2CReceive(uint32_t slave_addr, uint8_t reg)
{
I2CMasterSlaveAddrSet(I2C2_BASE, slave_addr, false); //reg = I2CMDR;
//read specified register on slave device
//specify that we are writing (a register address) to the
//slave device


I2CMasterDataPut(slave_addr, reg); //specify register to be read
//Annahme: reg=i2cmdr, HWREG(ui32Base + I2C_O_MDR) = ui8Data;

I2CMasterControl(I2C2_BASE, I2C_MASTER_CMD_BURST_SEND_START); //send control byte and register address byte to slave device

while(I2CMasterBusy(I2C2_BASE)); //wait for MCU to finish transaction
I2CMasterErr(I2C2_BASE); //Returns the error status, as one of I2C_MASTER_ERR_NONE,
//I2C_MASTER_ERR_ADDR_ACK, I2C_MASTER_ERR_DATA_ACK, or
//I2C_MASTER_ERR_ARB_LOST.


I2CMasterSlaveAddrSet(I2C2_BASE, slave_addr, true); //specify that we are going to read from slave device

I2CMasterControl(I2C2_BASE, I2C_MASTER_CMD_SINGLE_RECEIVE); //send control byte and read from the register we specified
while(I2CMasterBusy(I2C2_BASE)); //wait for MCU to finish transaction

return I2CMasterDataGet(I2C2_BASE); // Returns true if the I2C bus is busy; otherwise, returns false.
}

//uint8_t ReadAccel(uint8_t reg)
//{
//uint8_t accelData = I2CReceive(ACCEL_SLAVE_ADDR, reg);

//return accelData;
//}

void main(void) {
uint32_t slave_addr = 0x69;
uint32_t data_unser;
/*Port Init */
// set 16 MHz crystal as main oscillator, use 400 MHZ PLL divided by 12.5 = 16 MHz system clock
SysCtlClockSet(SYSCTL_SYSDIV_12_5|SYSCTL_USE_PLL|SYSCTL_XTAL_16MHZ|SYSCTL_OSC_MAIN);

//SysCtlClockSet(SYSCTL_SYSDIV_1 | SYSCTL_USE_OSC | SYSCTL_OSC_MAIN |
//SYSCTL_XTAL_16MHZ);
// let all external components some time to boot up
//SysCtlDelay(sleep_1ms * 20);


SysCtlPeripheralEnable(SYSCTL_PERIPH_I2C2); // enable the I2C peripheral for MPU sensor on PD0 = SCL, PD1 = SDA
while(!SysCtlPeripheralReady(SYSCTL_PERIPH_I2C2)){}
SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOE); // enable the GPIO port that is used for the I2C-Bus
while(!SysCtlPeripheralReady(SYSCTL_PERIPH_GPIOE)){}

GPIOPinConfigure(GPIO_PE4_I2C2SCL); // configure the pin muxing for I2C3 functions
GPIOPinConfigure(GPIO_PE5_I2C2SDA);
GPIOPinTypeI2CSCL(GPIO_PORTE_BASE, GPIO_PIN_4); // select the I2C function for these pins.
GPIOPinTypeI2C(GPIO_PORTE_BASE, GPIO_PIN_5);
// check if the peripheral access is enabled
// wait for the I2C module to be ready
I2CMasterInitExpClk(I2C2_BASE, SysCtlClockGet(), false); //initialize master and slave
// fast mode would be possible
while (1){
I2CReceive(slave_addr, 0x75);
data_unser = I2CReceive(slave_addr, 0x75);
}


}

Thanks for the help
Thomas

Thomas Metzger85 said:

Now it works.

it is noted that you've "switched from" I2C1 to I2C2 - a "proper" fix is more satisfying if it succeeds across (all) candidate Ports.    Might you detail your switch to another I2C channel?

I2C1 - if memory serves - "defaults" into I2C mode - which usually aids user success.     Both your posting - and recent contact from one of our clients - note "difficulty" w/I2C1 - which proves curious.

You wrote of "analog" pull-up resistors - did you mean "external resistors" - or an independent current source (used in that role).     The pull-down capacity of both your MCU & I2C Slaves are limited - perhaps I2C1 became damaged - necessitating your "switch to another I2C channel..."

Glad that you are, "up/running."