When purchase the Mi Band 1S, I tried to test the function of unlocking the phone with her, but I couldn't and I ended up leaving this side, even for not very interested. The problem is that the MI Band 1S did not appear in the list of Bluetooth devices connected, and so I couldn't add it as a trusted device for the phone to stay unlocked when she's around.
But last Monday I decided to try again, because I want to see if I fit with this functionality, and avoid having to keep entering all the time the unlock drawing. I also wanted to test whether the phone will not unlock accidentally in your Pocket. Now my Moto X Play already with Android 6.0.1, but the problem persisted. There was no way to make the MI Band 1S appear in the list of paired Bluetooth devices, She still works perfectly with the Mi and Mi Band Fit Tools.
After several attempts, I ended up finding the solution, which describe now:
First, It should be the MI Band 1S detectable. For this it is necessary to enter the Mi Fit, then in the option Alerts and then in the option Detectable and there for Activated.
Then, We must turn off the Bluetooth and turn it in the options of Android. To reset, immediately try to detect new devices, then will appear MI1S as device. Just click on the MI1S to pair.
With MI Band 1S already paired and paired Bluetooth device list, just go on the menu Security the Android, in the option Smart Lock and so on Trusted Devices. Then, Add MI1S as trusted device.
After that we can get back to Mi and disable the option Detectable, so that the battery consumption MI Band 1S is less.
By the time the MI Band 1S come running smoothly with the Smart locking function Moto X Play. I just have to put the password again after a long time without using your cell phone, otherwise it unlocks automatically when I am with MI Band 1S in the range of Bluetooth.