VL6180 always sending VCSEL Watchdog error

[SSchm.5]

Hello,

I was designing a board with a VL6180 and was surprised that the 0x4F register never uptaded to tell me that a new measurement was finished.

So I looked at the 0x4D register to see that it answered me 0x19. Whitch mean I have a VCSEL continuity test error BUT I can start a new measurement.

Which is really weird I must admit.

So to get a measurement, I send the message 0x01 to the 0x18 register and then I poll the 0x4F register until the "measurement finished" bit is set to 1.

But it never happen.

I tried to dismantle the VL and put another one but I got the same "error". If someone have an idea about the reasons this error appear,...

Note: the VL is powered by a step-down regulator which provide a voltage between 2.8 and 2.9V.

Thanks,

[VVita.1]

Hello SSchm.

I'm using VL6180 in a project and I'm having the same trouble you had. The most curious is the sensor can do the rangings, but if I read the register {0x4D} it sends me as answer 0x03, which shows I'm having a problem with VCSEL Watchdog. I don't know what can I do in this case.

Were you able to fix this problem?

Kind Regards.

[SSchm.5]

Hello,

The problem I had wasn't exactly due to the VL. I use a bus converter (I2C to differential) to communicate with a distant sensor board.

What I've seen on my oscilloscope: the timing of CLK line was higher than 1000ns (timing recommended by I2C). So the sensor couldn't communicate properly.

The real problem was my pullups on the distant sensor board. I changed them for 2k ohms and now everything is fine.

The values which worked for me are probably different for you.