I have tried to change the I2C address on one of two Lidar modules I have on this Arduino project. However, I always get a Nack in response. And then both give the same distance, even when I place a card in front of one of them. Has anyone had success in changing the address? I have tried several addresses like 0x63, 0x64, 0x65, 0x66 as well, to no avail. I have tried the two libraries (Lite and Litev3HP) with the same result. I also tried to use one in PWM mode, but due to timing issues, those distances are very large and inaccurate.
Try running through the steps on pages 4 and 5 here https://cdn.sparkfun.com/assets/9/a/6/a … ations.pdf - you have to have the unit ‘talk to itself’ (loopback serial number of device) before you can change the address 
The library calls to setI2Caddr does this ‘talk to itself’ process–this is true of both library versions. If I do this with only one Lidar attached, that works, However as soon as I power off the unit, the original address is back in play. Power cycling is very typical during development, so hard to avoid, having the base address return. Of course what I need is to have 2 of these units attached, so then applying a new address does not seem to work. Is there anyway to have the address change “stick”, so that power cycles do not affect it?