The device resets and stops responding when PWR_EN is raised high

[Rituraj]

I am using TOF vl53l8cx with stm32wb5mm-dk. I have used this sensor earlier with f407 and it worked completely fine . Now that I am working with a new mcu which only has 1 USART.  I am trying to LPUART for BLE and USART1 for tof BSP.

When the function CUSTOM_RANGING_SENSOR_Init(CUSTOM_VL53L8CX)

int32_t CUSTOM_RANGING_SENSOR_Init(uint32_t Instance)
{
int32_t ret;

if (Instance >= CUSTOM_RANGING_INSTANCES_NBR)
{
ret = BSP_ERROR_WRONG_PARAM;
}
else
{
reset_device();

switch (Instance)
{
#if (USE_CUSTOM_RANGING_VL53L8CX == 1U)
case CUSTOM_VL53L8CX:
if (VL53L8CX_Probe(Instance) != BSP_ERROR_NONE)
{
ret = BSP_ERROR_NO_INIT;
}
else
{
ret = BSP_ERROR_NONE;
}
break;
#endif /* Use custom ranging */
default:
ret = BSP_ERROR_UNKNOWN_COMPONENT;
break;
}
}

return ret;
} is called . The code reaches resetdevice(); function but the inside this function as soon as PWR_EN is raised high the device stops responding. 

[John E KVAM]

You get to reset_device() because of the line:

if (Instance >= CUSTOM_RANGING_INSTANCES_NBR)

So, use your debugger to find the value of those two. 

I'm going to guess those are equal.

And somewhere in the code, CUSTOM_RANGING_INSTANCES_NBR is defined. 

I'd add one to this and see what happens. 

Is CUSTOM_RANGING_INSTANCES_NBR defineable in the XCube somewhere?

That has to be it. 

(But it's only a guess on my part.)

- john

[Rituraj]

I tried debugging and the used &&0 with a few values so the device can atleast start working.

while debugging I came across :

do {

status |= RdMulti(&(p_dev->platform), address,

p_dev->temp_buffer, size);

status |= WaitMs(&(p_dev->platform), 10);

if(timeout >= (uint8_t)200) /* 2s timeout */

{

status |= (uint8_t)VL53L8CX_STATUS_TIMEOUT_ERROR;

break;

}else if((size >= (uint8_t)4) 

                         && (p_dev->temp_buffer[2] >= (uint8_t)0x7f))

{

status |= VL53L8CX_MCU_ERROR;

break;

}

else

{

timeout++;

}

}while ((p_dev->temp_buffer[pos] & mask) != 0x38);

return status;

}

This is part of the function 

 _vl53l8cx_poll_for_answer(

VL53L8CX_Configuration *p_dev,

uint8_t size,

uint8_t pos,

uint16_t address,

uint8_t mask,

uint8_t expected_value)

inside the vl53l8cx_api.c

The device gets stuck into this loop and doesn't get initialized.

Also I didn't find any  CUSTOM_RANGING_INSTANCES_NBR declaration is cube mx.

[John E KVAM]

If power is applied to the sensor, and the LPn is pulled high, the 'poll_for_answer' will respond. The sensor is complex, but the I2C interface is dead simple. Unless you have the i2C/SPI switch wrong. That would cause an issue. Pull it down for I2C. 

if you don't get that far, then somehow you have a plumbing issue. Something is not connected correctly.

- john