VL6180x not working after a few minutes

[Paul Lee]

Posted on June 24, 2018 at 21:18

I am running the vl6180x without an object being placed before and it stop working. No interrupt status, value and error code. When an object is placed in front of it in startup, it works without issue but when removed for a few minutes, the detection stops working. Any ideas why it would do this? I am running only range detection in continuous mode, autoVHV repeat. 

[John E KVAM]

More than likely it's a failure of the I2C. Unless you pay particular attention to the pull-ups, line thickness and line length, noise will cause a 'glitch' which results in a false bit, and one ends up with a Bus-stuck-low - which can be checked with a scope. Most MCUs have a mechanism to clear this -or you can put a bunch of zeros on the bus until it clears. My first rule of thumb - a bigger pull-up. (But you have to get a scope and look at the slope and the noise to be sure.)