Bluetooth2 Click

How does it work?

Bluetooth 2 Click uses the WT41u, a fully integrated Bluetooth 2.1 + EDR, class 1 module combining antenna, Bluetooth radio, and an on-board iWRAP Bluetooth Stack. The WT41u is a replacement for the WT41. The WT41u provides a superior 110 dB link budget and more than 1000-meter line-of-sight connectivity for Bluetooth applications where extreme radio performance or reliability is required. It also constitutes an ideal solution for developers that want to quickly integrate extremely high performing Bluetooth wireless technology into their design without investing several months in Bluetooth radio and stack development. The WT41u uses Bluegiga's iWRAP Bluetooth stack, which is an embedded Bluetooth stack implementing 13 different Bluetooth profiles and Apple iAP connectivity. By using WT41u combined with iWRAP Bluetooth stack and Bluegiga's excellent technical support, designers ensure quick time-to-market, and low development costs and risks.

Targeted applications are Handheld terminals, Industrial devices, Point-of-Sale systems, PCs, Personal Digital Assistants (PDAs), Computer Accessories, Access Points, Automotive Diagnostics Units.

Bluetooth 2 Click uses a standard UART interface for communicating with other serial devices. Implemented WT41u module UART interface provides a simple mechanism for communicating with other serial devices using the RS232 protocol. Four signals are used to implement the UART function. When WT41u is connected to another digital device, UART_RX and UART_TX transfer data between the two devices. The remaining two signals, UART_CTS and UART_RTS, can be used to implement RS232 hardware flow control where both are active low indicators. All UART connections are implemented using CMOS technology and have signaling levels of 0V and VDD. UART configuration parameters, such as data rate and packet format, are set using WT41u software.

Besides the commonly used UART RX, TX, RTS, and CTS, Bluetooth 2 Click also has Reset, PIO7, and AIO pins, which are routed to the RST, PWM and AN pins of the mikroBUS™ socket, respectively. The SPI port can be used for system debugging. It can also be used for programming the Flash memory and setting the PSKEY configurations. WT41u uses 16-bit data and 16-bit address serial peripheral interface, where transactions may occur when the internal processor is running or is stopped. SPI interface is connected using the MOSI, MISO, CS, and SCK pins.

The communication interface can be selected by moving the SMD jumper designated as COM SEL to an appropriate position (CTS or CS) for RS232 or SPI protocol.

This Click Board™ is designed to be operated only with a 3.3V logic level. A proper logic voltage level conversion should be performed before the Click board™ is used with MCUs with different logic levels.

Specifications

Pinout diagram

This table shows how the pinout on Bluetooth2 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Analog	AIO	1	AN	PWM	16	IO7	GPIO
Reset	RST	2	RST	INT	15	RST	UART RTS
SPI Chip Select	CS	3	CS	RX	14	RX	UART RX
SPI Clock	SCK	4	SCK	TX	13	TX	UART TX
SPI Data OUT	SDO	5	MISO	SCL	12	NC
SPI Data IN	SDI	6	MOSI	SDA	11	NC
Power Supply	3.3V	7	3.3V	5V	10	NC
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Bluetooth2 Click electrical specifications

Software Support

We provide a library for the Bluetooth 2 Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

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

Library Description

This library contains API for Bluetooth 2 Click driver.

Key functions

• bluetooth2_factory_reset This function factory resets the device.

• bluetooth2_set_device_name This function sets the local device name.

• bluetooth2_generic_write This function writes a desired number of data bytes by using UART serial interface.

Example Description

This example reads and processes data from Bluetooth 2 clicks.

 void application_task ( void ) 
 { 
     bluetooth2_process(); 
     if ( app_buf_len > 0 )  
     { 
         Delay_ms( 200 ); 
         bluetooth2_process(); 

         if ( strstr( app_buf, RSP_RING ) ) 
         { 
             connection_flag = 1; 
             send_cnt = 0; 
         } 
         if ( strstr( app_buf, RSP_NO_CARRIER ) ) 
         { 
             connection_flag = 0; 
             send_cnt = 0; 
         } 
         log_printf( &logger, "%s", app_buf ); 
         bluetooth2_clear_app_buf(  ); 
     } 

     if ( connection_flag == 1 && send_cnt++ > SENDING_FREQ ) 
     { 
         bluetooth2_generic_write( &bluetooth2, TEXT_TO_SEND, strlen( TEXT_TO_SEND ) ); 
         send_cnt = 0; 
     } 

     Delay_ms( 1 ); 
 }

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

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.Bluetooth2

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 MikroElektronika compilers.

mikroSDK

This Click board™ is supported with mikroSDK - MikroElektronika 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.