Introduction
Microchip’s RNBD451 Bluetooth® Low Energy Module has fully certified 5.2 connectivity in compact form. With all of its advanced features, it allows the Bluetooth Low Energy connectivity to be included in designs with minimal engineering.
The RNBD451 module provides the control interface based on ASCII commands sent over UART.
Interactive ASCII commands enable the RNBD451 module to be configured without complex configuration tools and complex coding. The RNBD451 module supports both peripheral and central Generic Access Profile (GAP) roles, actively scanning for other connectable devices.
With the RNBD451 module, the features of Bluetooth, such as Data Length Extension (DLE) and Bluetooth Low Energy secured connections, are supported and enabled by default. DLE increases the Bluetooth Low Energy packet Protocol Data Unit (PDU) length and provides higher throughput. LE secure connections feature support provides additional security during pairing against passive eavesdropping.
The RNBD451 module also supports Bluetooth 5.x-specific features like advertising improvements through “Advertising Extension”, which increase the possibilities for advertisement data configuration that opens various Bluetooth Low Energy beacon applications. Support for additional PHYs is included beyond the original 1M. It supports the 2M with double symbol rate compared to 1M (for increased throughput) and Coded (for increased range).
Features
The RNBD451 Bluetooth Low Energy module has the following features:
- ASCII Command Interface
- Transparent UART
- Custom/Special Interest Group (SIG) Defined GATT Services
- Remote Command Console
ASCII Command Interface
The ASCII commands primarily control the RNBD451 module. The UART receives the ASCII commands from the host device/MCU. The ASCII commands can control functions such as connection setup/teardown, accessing Generic Attribute Profile (GATT) characteristics, changing configuration settings and reading status. The UART can operate in Command mode to receive ASCII commands or Data mode to exchange data using Transparent UART based on the built-in Microchip transparent profile.
Transparent UART
The RNBD451 module introduces a private GATT service named Transparent UART. This service simplifies serial data transfers over Bluetooth Low Energy devices. The RNBD451 module Transparent UART seamlessly transfers serial data from its UART over a Bluetooth Low Energy connection, providing an end-to-end data pipe to another Bluetooth device, such as the RNBD451 module or smartphone.
Custom/SIG Defined GATT Services
The RNBD451 module has the capability to define up to six public and four private defined GATT services. Each service allows up to eight characteristics. The internal Non-Volatile Memory (NVM) configuration settings store all the service definitions.
Remote Command Console
The RNBD451 module supports Remote Command mode, which allows a remote device to access Command mode via Bluetooth link. This feature requires the user to first enable the Transparent UART function.
Hardware Platform
The hardware platform made available to evaluate the RNBD451 module is RNBD451 Add On Board. The detailed information about the RNBD451 Add on board will be discussed in the next session.