Problem and solving

 Problem one: Microbit Bluetooth signal problem

When testing the BLE based mesh data transfer, the Bluetooth signal tend to be very weak compare to other devices in the room. To solve the problem, I have tested the signal strength and the result is shown below. 

Figure 1: Bluetooth signal strength test result

This situation also occurs in the connection between the pi and microbit. The connection could be very unstable and may easily disconnect when using.