"Packet too big" during BLE connection request on BBC Microbit, RFDui…

[FedericoBusero]

…no, nRF51822, ...

Problem: When using BLE on boards using the library arduino-BLEPeripheral, the Blynk connection request nearly always fails with the message "Packet too big".

Following boards are using the library arduino-BLEPeripheral:

• BBC Microbit
• RF Duino BLE
• RedBearLab nRF51822
• and other nRF51822 based boards
• nRF8001 based boards

Cause The main cause of this problem is the size of the receiving buffer, which was only 20 bytes. Other Blynk implementations of BLE boards however have a receiving buffer size of 512 bytes.

Changes: fix buffer size bug & make the code more in line with other Blynk BLE implementations:

• Receiving buffer size increased
• Change service UUID from Nordic UART to Blynk UUID
• Remove unnecessary advertisement data (name descriptors) to make advertisement data smaller
• Change BLE mode from "Write no response" to "write"
• Removed unnecessary source code, mainly debug info

Description

[Describe what this change achieves]

Issues Resolved

[List any existing issues this PR resolves; include Fixes #xxx or Closes #xxx (where xxx is issue number)]

[FedericoBusero]

See issue https://github.com/blynkkk/blynk-library/issues/459

[vshymanskyy]

Thanks for a valuable contribution. I will review and test it soon!