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CBoyc.1
Associate
September 2, 2021
Question

Unable to communicate to VL53L0CX

  • September 2, 2021
  • 3 replies
  • 1310 views

Working on a board that uses a VL53L0CX. But I do not seem to be able to communicate with the sensor and have even tried to scan i2c addresses with no luck. I am hoping someone here can take a look at the schematic I have for the sensor and let me know if I made a mistake that I am glossing over. Not shown here is that SDA/SCL are both pulled up with 4.7k resistors.

0693W00000Dm0tYQAR.png0693W00000Dm0sBQAR.png

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3 replies

Julien NGUYEN
ST Employee
September 2, 2021

Hi,

There is no internal I2C pull up resistors in the VL53L0X, you need two external pull up. Thanks, Julien

CBoyc.1
CBoyc.1Author
Associate
September 2, 2021

Thanks for the quick reply. Not shown are the pullup resistors which are 4.7k ohm each.

CBoyc.1
CBoyc.1Author
Associate
September 7, 2021

Changed Pull-ups on SDA and SCL from 4.7k yo 1k. Does not appear to have made any kind of difference.

John E KVAM
ST Employee
September 7, 2021

I have long held that there are only a few hardware things that can keep the VL53 sensors from responding.

1) lack of power. Looks like yours is OK

2) Xshut not being pulled up. Again looks like yours is good

3) I2C not configured correctly - and it looks like you've got that about right.

4) Wires are too long for the I2C protocol to work correctly.

So that leaves software.

I'm going to guess there is a configuration issue somewhere.

  • john