I sent my phone down next to the Sensor and walked away. An hour later it was still no updating. The bar remained blank. After looking through some old posts, I found the solution. When Bluetooth was first created, sometimes the wifi transmitter would conflict with the bluetooth transmitter. I don't know how it was fixed but i do know that it happen on simple devices such as this device. I turned the Wifi transmitter off on my phone and only received data from my mobile network. The Speed Sensor updated within a few minutes. I did keep moving my bike tire to keep it awake.