VL53L0X intermittent failure: no IR emission, re-init fails, only VL53L0X power-cycle recovers

[Bena_Rock]

Hello everyone,

I am using a VL53L0X and have encountered an intermittent failure. I would like help identifying the possible cause and the next debugging steps.

Hardware setup:

• MCU: Cortex-M0, model MM32SPIN06PF

• I2C: GPIO bit-banged I2C in open-drain mode, with 4.7 kΩ pull-ups.

• An ENS210 temperature/humidity sensor is also on the same I2C bus. ENS210 address: 0x43.

• VL53L0X 7-bit address: 0x29; 8-bit address: 0x52.

• The VL53L0X XSHUT pin is only pulled up to 3.3 V through a 10 kΩ resistor. It is not controlled by an MCU GPIO.

• VL53L0X supply voltage: 3.3 V.

• VL53L0X API version: 1.0.4.

Failure symptoms:

• The VL53L0X works normally at first, but occasionally malfunctions.

• When the failure occurs, no IR emission can be seen from the VL53L0X using a phone camera. Can IR normally be seen with a phone camera? ____

• Pressing a hardware button to re-initialize the VL53L0X does not recover it.

• Only after power-cycling the VL53L0X alone and then pressing the button to re-initialize it does the VL53L0X return to normal operation.

My main questions:

1. Is it possible that, because XSHUT is not controlled by the MCU, the software cannot perform a true hardware reset of the VL53L0X?

2. Could sharing the I2C bus with the ENS210 cause bus lock-up or state conflicts?

3. What logs, waveforms, or register data should I capture to locate the root cause?

Thank you. Any help would be appreciated.

[Bena_Rock]

When the failure occurs, no IR emission can be seen from the VL53L0X using a phone camera. Under normal operation, the IR emission can be seen with a phone camera.