WIFI crashes when a sensor is connected

Yoann,

This seems to be related to a power supply issue. Can you monitor the 3.3V with a oscilloscope to check for any transients? Can you temporarily replace the battery and LDO with a higher capacity bench power supply?

Hi Lenio,

I tested it with an external battery, the problem still exist.

The BME280 is accessed by I2C and On Board LaunchpadXL sensors are also connected to I2C bus,
could it be a collision problem on the I2C bus ?

Yoann

It could, however I would still verify the 3.3V with a scope if possible.

Depending on how the software is structured, a pending acknowledgment could cause the master to wait indefinitely. If you believe that is the case, simply remove the I2C routines while still maintaining the sensor powered and connected. 

Hi,

sorry for not having respond sooner I didn't have noticed your reply.

The problem is solved. It appeared that the program were stuck in an endless loop in I2C_IF.c / function Transac() and that BME280 sensor kept SDA line to a low level.

I have resolved it by putting a timout in the endless loop and by forcing the I2C slave (BME280 sensor) to give back the I2C master (CC3200MODXL) the control of SDA line by toggling the clock on SCL line.

I put the code below in case someone have a similar problem :

/*********************************************/
/******GETTING OUT OF ENDLESS LOOP******/
IN I2C_IF.c :

static int
I2CTransact(unsigned long ulCmd)
{
....
//
// Wait until the current byte has been transferred.
// Poll on the raw interrupt status.
//
int i=0;
while((MAP_I2CMasterIntStatusEx(I2C_BASE, false)
& (I2C_INT_MASTER | I2C_MRIS_CLKTOUT)) == 0)
{
//Report("STUCK : count = %d\n\r",i);
MAP_UtilsDelay(30000);
i++;
if(i>3){break;}
}
i=0;
....
}


/*********************************************/
/*****SETTING SDA LINE TO HIGH AGAIN*****/
//RECATIVATE SDA LINE WHEN BME280 KEEPS IT IN LOW STATE
//HAVE ALSO TO ADD A TIMEOUT IN ENDLESS LOOP IN I2C_TRANSAC FUNCTION IN I2C_IF.c
void i2cbme280PB(void){
int i=0;
PRCMPeripheralClkEnable(PRCM_GPIOA1, PRCM_RUN_MODE_CLK);
PinTypeGPIO(PIN_01, PIN_MODE_0, false);
GPIODirModeSet(GPIOA1_BASE, 0x4, GPIO_DIR_MODE_OUT); // SCL as IO_OUT

PinTypeGPIO(PIN_02, PIN_MODE_0, false);
GPIODirModeSet(GPIOA1_BASE, 0x8, GPIO_DIR_MODE_IN); //SDA as IO_IN

int j=0;
while(j<100){
GPIO_IF_Set(PIN_01, GPIOA1_BASE, 0x4, 0);
MAP_UtilsDelay(1);//for (i=0;i<50;i++);
GPIO_IF_Set(PIN_01, GPIOA1_BASE, 0x4, 1);
j++;
}

PinTypeI2C(PIN_01, PIN_MODE_1);
PinTypeI2C(PIN_02, PIN_MODE_1);
I2C_IF_Open(I2C_MASTER_MODE_FST);
}

To avoid any problem I call i2cbme280PB() before and after every I2C transaction, this is kind of brutal but it works, like below :

i2cbme280PB();
GetBME280Temp(dataBuffTemp);
i2cbme280PB();

Yoann

Thanks for the update Yoann.

-/Praneet