Zigbee is a popular wireless communication protocol used to transfer a small amount of data with very low power. It is widely used in applications where data has to be shared among many nodes within personal space, and with the advent of the Internet of things (IoT), the application for Zigbee is fast growing. It is used in home automation, asset tracking, remote data collection, and much more. If you are already familiar with the architecture of Zigbee and Zigbee protocols, then you already know that wireless communication between two XBee modules can be done without any additional microcontrollers, but in practical application, these modules will always be interfaced with a microcontroller to read and send data. Let’s take that a step further and learn how to establish Zigbee communication using Arduino and NodeMCU boards.

Difference between Zigbee and XBee

It is important to clarify at the beginning itself that XBee is a module, a product, which supports many wireless communication protocols like ZigBee, Wi-Fi (Wi-Fly module), 802.15.4, 868 MHz modules, etc. Whereas, Zigbee is a standard protocol used to establish wireless networking (ZigBee communication). Often people use these two terms interchangeably but it shouldn’t be done so. To establish Zigbee communication, we need a receiver (endpoint). For this, an XBee module connected with Arduino/NodeMCU will do, and this will communicate wirelessly with another XBee module (coordinator) that sends data, will be connected to another Arduino board.

Hardware Requirements for Establishing Zigbee Communication

1 x Arduino Nano

1 x NodeMCU

2 x XBee Pro S2C modules

1 x XBee explorer board (to program XBee)

USB cables

LED (along with a 220-ohm resistor)

Push Button

Configuring XBee Modules using XCTU Software

Basically, the XBee module can be configured as Coordinator, Router, or End device. To make it work as we desire, first, we have to configure them using XCTU software. You can download and install the XCTU software using the given link.

Use USB to serial converter or an explorer board to connect the XBee module with a PC or Laptop. Connect the XBee module to the Explorer board and plugin using a USB cable. We will get into the details on how exactly we can use this software and configure the module, but before we do that, let's get our hardware ready.

Interfacing XBee with Arduino (Transmitting Side)

For this side of the connection, we’ve used Arduino Nano. Arduino Uno or NodeMCU boards could also be used. The complete circuit diagram to interface XBee with Arduino nano is shown below.

In the above Arduino XBee circuit diagram, we have used a push-button which, when pressed, will transmit data. For this, connect one end of the button to D5 of Arduino and the other end of the button to GND.

Connect VCC (pin 1) of XBee module to 3.3V of Arduino Nano and GND (pin 10) of XBee to GND of Arduino Nano. These two connections make up for powering the transmitting side XBee module. Connect Dout (pin 2) to D2 of Arduino Nano and Din (pin 3) to D3 of Arduino Nano. I used a breadboard to build this circuit and my hardware set-up with all the connections is shown below.

Interfacing XBee with NodeMCU (Receiving side)

For this, we’ve used NodeMCU, but it has certain constraints. You can also use Arduino Nano or Arduino Uno for the purpose. The idea of using an Arduino to transmit data and NodeMCU to receive data is that it will have a more practical application like the Arduino can collect some sensor parameters and send it to the NodeMCU via ZigBee, then NodeMCU can process this data and share it or take any action via the Internet as required. The complete circuit diagram to interface XBee with NodeMCU is shown below.

Connect Gnd(pin10) of XBee to GND of NodeMCU and Connect Vcc (Pin1) of XBee to 3.3V of NodeMCU. The above-mentioned two connections supply the power to the XBee module as well. Then connect Dout (pin2) of XBee to D6 pin of NodeMCU and Din (pin3) of XBee to D7 pin of NodeMCU for receiving data.

As an indication of whether the data is received or not, we’ve used LED. For this, connect LED anode to D2 of NodeMCU and LED cathode to GND through a 220ohm resistor of NodeMCU. Again, I used a breadboard to build this circuit and my hardware set-up with all the connections is shown below.

Downloading and Installing XCTU Software

To set up, configure and test your XBee devices. You need XCTU software. It’s an easy-to-use, free, multi-platform application for RF XBee modules. Download the XCTU software here and it’ll guide you to install it as well. After that, open the application and make sure your XBee module is connected properly. Check the COM port of the explorer board in the device manager.

Installing Firmware to XBee Modules

Firmware should be installed in both the XBee modules first, for that we’re using the XBee development board.

Step 1: Open XCTU software and click on “Discover boards”.

Step 2: Select the COM port to which the XBee module is connected and click on “Next”.

Step 3: Keep the default settings and click on “Finish”.

Step 4: Now, on the pop-up window, click on “Add Selected Devices”.

Step 5: Now, the XBee module will appear on the left side of the window. Click on it to update the user interface.