VL6180 GPIO0 / CE and IIC Address Change

[Brian_Azzopardi]

Hello all,

We have multiple VL6180 sensors on a common IIC bus.

Upon system start up, we are enabling one sensor via its GPIO0 / CE pin, initialising it, changing its IIC address, disabling it, and repeating these steps for all sensors on the IIC bus.

We noticed that upon disabling the chips (GPIO0 / CE pin low) and enabling them again (GPIO0 / CE pin high) to take measurements, their address changes again to the default (0x29) and we cannot communicate with them using the newly-assigned addresses. 

Moreover, the sensors would need to be re-initialised before measurement (using the default address).

So am I correct in saying that when low, the GPIO / CE pin completely shuts down the chip and any set registers (e.g. register 0x212 that holds the IIC address) are reset to their default address? Do you have to keep the chips enabled (GPIO / CE pin high) after address is changed?

Thanks for your input!

Brian

[John E KVAM · Accepted solution]

Exactly - 

Your description of how to re-address the sensors is perfect, up until you disable them. Skip that bit.

Once the addresses are changed, they should be very low power. So, enable one, change its address and enable the next and change its address. Repeat as often as you have chips.

If you change all the address, you can occasionally query the original address (0x29). If any of the chips have lost power and rebooted - they will have gone back to that original address.

- john

[Brian_Azzopardi]

Many thanks @John E KVAM !

Brian