ZigBee Click

How does it work?

ZigBee Click is based on the ETRX357, a low power Zigbee Radio module integrating a 2.4 GHz compliant transceiver with many advanced peripherals from Silicon Labs. The ZigBee protocol is a set of standards for wireless connectivity for usage between any devices over short to medium distances. It uses the IEEE 802.15.4 radio specification running on the 2.4GHz band, plus three additional layers for networking, security, and applications. What makes this module unique is its use of a mesh network architecture which, in bucket chain style, passes data from one node to the next until it lands at its destination.

The ETRX357 module is pre-loaded with a standalone bootloader that supports over-the-air bootloading as well as serial bootloading of the new firmware, using the FW pin on the ZigBee Click. The module is controlled using the default firmware consisting of simple AT commands. Parameters that define the functionality of the module and also allow standalone functionality are saved in non-volatile memory organized in so-called S-Registers. The commands and responses pass through the serial port of the ETRX357 as ASCII text, so a simple terminal application will usually suffice.

The industry-standard serial wire, JTAG programming, and debugging interfaces together with the standard ARM system debug components help to streamline any custom software development. In addition to this, several MAC functions are also implemented in hardware to help to maintain the strict timing requirements imposed by the ZigBee and IEEE802.15.4 standards. The module is also able to act as a coordinator and Trust Centre through external host control. The AT-style command line supplies all the tools required to set up and manage a Zigbee network by allowing easy access to the low-level functionality of the stack.

ZigBee Click communicates with MCU using the UART interface as its default communication protocol, but it is also left the option for the user to use other interfaces such as SPI and I2C if he wants to configure the module and write the library by himself. The selection between UART and I2C can be done by positioning SMD jumpers labeled as COMM SEL to an appropriate position. Note that all the jumpers must be placed to the same side, or else the Click board™ may become unresponsive.

Additional functionality such as reset and interrupt are provided and routed at RST and INT pins of the mikroBUSTM, as well as serial UART connections CTS and RTS, routed on the CS and PWM mikroBUSTM pins. To simplify deployment, the Click boardTM features the CMT-8540S-SMT magnetic buzzer controlled by the ZigBee module used for audible signalization and notification. You can create different sound patterns using the Sound library supported in our compilers. Signal frequency determines the sound pitch, and the duty cycle determines the amplitude (sound volume).

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 ZigBee Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
FW Update	FW	1	AN	PWM	16	CTS	UART Interface / SPI Chip Select
Reset	RST	2	RST	INT	15	INT	Interrupt
UART Interface	RTS	3	CS	RX	14	TX	UART TX
SPI Clock	SCK	4	SCK	TX	13	RX	UART RX
SPI Data OUT	SDO	5	MISO	SCL	12	SCL	I2C Clock
SPI Data IN	SDI	6	MOSI	SDA	11	SDA	I2C Data
Power Supply	3.3V	7	3.3V	5V	10	NC
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

ZigBee Click electrical specifications

Software Support

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

Library Description

Library provides functions and macros for complete control over device. Library has one buffer that collects data with zigbee_process function. You can clear it and write it with library functions, you can also check if there is new data in buffer with zigbee_resp. There is generic function for sending one string of data, and one additional function for concating two string so you can use predefined AT commands from library.

Key functions:

• void zigbee_send_cmd ( uint8_t *cmd_buf ) – Sends string to device
• void zigbee_process ( uint8_t process_b ) – Collects data to library buffer
• uint8_t zigbee_resp ( void ) – Checks if there is new data in library buffer

Examples description

The application is composed of three sections :

• System Initialization – Initialization of UART module and additional pins
• Application Initialization – Initialization of driver, UART ISR and then configures device. Depending on previous selected device mode it creates new PAN network or joins to one.
• Application Task – * Host mode: Broadcasts message ‘MikroE’ every 3 seconds. * User mode: Cheks if something is received.

void application_task ( )
{
    if ( DEV_HOST == dev_mode )
    {
        //Broadcasts message 'MikroE' over it's PAN network
        zigbee_send_at( ZIGBEE_AT_BCAST, &AT_BCAST_MSG[ 0 ] );
        resp_wait(  );
        Delay_ms( 3000 );
    }
    else if ( DEV_USER == dev_mode )
    {
        //Checks if there is something received
        resp_wait(  );
    }
}

Additional Functions :

• void logger_function ( uint8_t *demo_txt, uint8_t write_macro ) – Wrapper function
• void resp_wait ( ) – Function for waiting for complete response

The full application code, and ready to use projects can be found on our LibStock page.

Other mikroE Libraries used in the example:

• UART
• C_String

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. The terminal available in all MikroElektronika compilers, or any other terminal application of your choice, can be used to read the message.

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.