Great question — I’ve worked with VL53L sensor modules and ESP32, so here’s what I found works best:
When using the VL53L8CX with ESP32 over I2C, the key points to check are:
1. Pull-up Resistors: ESP32’s internal pull-ups are often too weak for some sensors. Use external 4.7 kΩ or 10 kΩ pull-ups on SDA & SCL lines to 3.3V to help signal integrity, especially when longer wires or multiple devices are involved.
2. I2C Speed / Clock Stretching: Try lowering the I2C clock speed (e.g. to 100 kHz) instead of the default 400 kHz. Some VL53L sensors may not respond well to faster speeds, especially during measurement cycles where they stretch the clock.
3. Address Conflict / Multiplexing: If you have multiple sensors or other I2C peripherals, make sure the VL53L8CX has the correct address or use an I2C multiplexer. Address collisions are a common source of “no response” errors.
4. Power & Ground Stability: Ensure stable 3.3V supply with decoupling capacitors close to the sensor. Ground loops and noise can break communication.
5. Library / Initialization Sequence: Use the official ST-provided or well-tested libraries for VL53L8CX. Initialize the sensor only after I2C bus begins. Also check for return status codes after init — if initialization fails, don’t proceed further.
