Once in a while you might see your sensor's LED flashing purple for about 30-60 seconds. This will almost definitely happen the first time you set-up your sensor, and it's simply our way of indicating that the sensor is downloading the latest firmware. When new features and changes are made on our end we will push an OTA (over-the-air) update to your sensor. Your sensor will receive the update automatically and you'll see the flashing purple for about 30-60 seconds before it goes to breathing white and then turning back off. This is all standard and nothing to be alarmed about (it's actually a good thing because it means your sensor is keeping up to date!).