Multiple VL53L3CX with the same interrupt wire

[AAmor.2]

Hello,

I'm looking for using multiple sensors (10 exactly) in my systems. I have two tricky specifications :

• get measurement frequency of at least 50Hz
• limited as best as possible the space of sensors PCB

Therefore I have the idea to use a single interrupt wire (GPIO1) for several sensors and play with timings in order to enhance the efficiency in term of wire / time to get data.

Do you think it seems possible to design this way ? (Because in API manual it said is mandatory to assign each sensor wires (XSHUT and GPIO1) to 2 pins of our microprocessor in a multiple sensor design)

Thank you for your future help.

[John E KVAM]

I built a system with 9 sensors. (There is video and software on the ST site. Look for 2D-lidar.)

I used the VL53L1 and the Ultra-lite driver, so you can't use the code - unless you just use it as psuedo-code.

But it does prove it can be done.

You will need the XSHUT - you cannot get away from that.

But the interrupt is not manditory - you can poll with an "are you done yet?"

(This is what I did in my code. Start them in order, then poll them in the same order. By the time you finish getting the answer from the first, the second should be ready.)

Or you can hook several to the same interrupt pin. When the interrupt fires, you can ask each chip, "are you done yet", until you get to the one that says 'yes'.

I toyed with the idea of using an I2C GPIO expander. By placing it in the middle of a series of sensors, it cut down the number of wires on my flex. You still need a XSHUT and interrupt to each chip, but it really cuts down the number of wires you need to connect to the host.

Good luck,

• john

[AAmor.2]

Thank you for your hopefully answer.

However, do you think the polling mode will generate more latency in term of frequency to get data than the interrupt mode ?

Because achieve 50Hz per measure seems to be a real challenge with the VL53L1CX sensors...

[FPayn.1]

I have an autonomous robot project that uses seven VL53L0X sensors on two I2C busses. See this post (and related ones) for the details. I could have just as easily put all seven sensors on the same I2C bus, but since I had two available....

Frank