Set permanent I2C address to TOF

[fpiondrancy]

Hello,

I have already use VL53L0X sensor provided by AZ-Delivery.

My main problem is that I2C address can be changed but NOT permanently.

I am looking to "Adafruit VL53L4CX Time of Flight Sensor". But I don't want to discover the same problem, that is I2C address can not be change permanently. 

Does the base-component VL53L4CX have the same "disability" ?

Is there a TOF component allowing to set and fix this important behavior ?

Best regards.

[John E KVAM · Accepted solution]

The VL53L sensor family all respond to the same address, and all require an address change if you use more than one of them. In fact the all use the same IP to do the I2C interface.

The problem with adding some persistent memory is that it would require things like a +12 volt supply and additional pins. It drives up the cost and most people are fine with it. A bit of hassle when you write the code but after that It's not much of an issue.

I like the Adafruit boards (as well as the Pololu and Sparkfun ones). They work well but you are going to need to copy that address change software over from your VL53L0 implementation. 

Sorry about that. 

[fpiondrancy]

Thanks.

On other simple device like SRF08 (Ultra sonic range finder), address can be changed by software and saved permanently. And the component needs only 5vdc.

What I understand of the possibility to set the address at each time the software starts, is to use two additional wires (GPIO & XSHUT) with each sensor, and to process an "initialisation" sequence.

It is more complex than to have a dedicated address.

My robot  manages 3 sonars SRF08, 2 300w motors (with Saberbooth board), 1 GPS, one magnetometer LSM303, 2 USB cameras and 1 2D lidar. In my case, economy of wires number is important. But it's only my point of view 😉

Best regards.

[fpiondrancy]

It's ok.

I succeed to do it.

- shutdown all Tofs with the shutdown-pin set to 0;

- on each tof,

  * set shutdown pin to 1

const VL53L0X_I2C_SLAVE_DEVICE_ADDRESS = 0x8A
let defaultAddress = 0x29
let realCurrentAddress = i2cBus.readByteSync(defaultAddress, VL53L0X_I2C_SLAVE_DEVICE_ADDRESS)
if (realCurrentAddress == defaultAddress) {
    i2cBus.writeByteSync(0x29, VL53L0X_I2C_SLAVE_DEVICE_ADDRESS, newAddress)
}