Bluetooth Click

How does it work?

Bluetooth Click is based on the RN-41, a Class 1 Bluetooth module from Microchip. The auto-discovery/pairing on this module does not require software configuration. It has a 15dBm output transmitter with -80dBm of typical receive sensitivity for transmitting data using FHSS/GFSK modulation on 79 channels and at 1MHz intervals. The 3Mbps data rate communication is secured with 128-bit encryption, with error correction, which guarantees packet delivery. The 3Mbps data rate is a maximum that can be achieved in a burst in HCI mode, while the 1.5Mbps is sustained.

To communicate with the host MCU, the Bluetooth Click uses the UART interface with commonly used UART RX and TX as its default communication protocol. It can operate at baud rate speeds from 1200bps to 921Kbps, while non-standard baud rates can be programmed. The hardware flow control pins UART CTS/RTS are disabled and can be enabled by soldering J1 and J2 jumpers. The RN-41 module can be programmed over the UART interface of the mikroBUS™ socket with a simple ASCI command language similar to the Hayes AT protocol. The module can be reset via the RST pin with active LOW.

This Click board™ features four more jumpers labeled PIO3, PIO4, PIO6, and PIO7. The auto-discovery function can be enabled by soldering jumper PIO3. To set the factory default values, you should solder the PIO4 jumper, and this feature is critical when the module has been misconfigured. The auto-master mode can be set by soldering the PIO6 jumper; the standard application runs on SPP/DUN Master and Slave. The firmware can set the baud rate but also can be forced to 9600bps by soldering the PIO7 jumper.

This Click board™ can only be operated with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used, as a reference, for further development.

Specifications

Pinout diagram

This table shows how the pinout on Bluetooth Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	NC
Reset	RST	2	RST	INT	15	NC
	NC	3	CS	RX	14	TX	UART TX
	NC	4	SCK	TX	13	RX	UART RX
	NC	5	MISO	SCL	12	RTS	UART RTS
	NC	6	MOSI	SDA	11	CTS	UART CTS
Power Supply	3.3V	7	3.3V	5V	10	NC
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Bluetooth Click electrical specifications

Software Support

We provide a library for the Bluetooth Click as well as a demo application (example), developed using MIKROE compilers. The demo can run on all the main MIKROE development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager (recommended), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for Bluetooth Click driver.

Key functions

• The function enter the command mode of the RN-41 Bluetooth module on Bluetooth Click board.

• The function set the authentication value to the RN-41 Bluetooth module on Bluetooth Click board.

• The function set security pin code string to the RN-41 Bluetooth module on Bluetooth Click board.

Example Description

This example reads and processes data from Bluetooth clicks.

 void application_task ( void ) 
 { 
     bluetooth_process( "AOK" ); 
 }

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager (recommended), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.Bluetooth

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MIKROE compilers.

mikroSDK

This Click board™ is supported with mikroSDK - MIKROE Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.