Raspberry Pi with xbee in python-gkarthik

ZigBee is a communication device used for the data transfer between the controllers, computers, systems, really anything with a serial port. As it works with low power consumption, the transmission distances is limited to 10–100 meters line-of-sight. ZigBee devices can transmit data over long distances by passing data through a mesh network of intermediate devices to reach more distant ones. ZigBee is typically used in low data rate applications that require long battery life and secure networking. Its main applications are in the field of wireless sensor network based on industries as it requires short-range low-rate wireless data transfer. The technology defined by the ZigBee specification is intended to be simpler and less expensive than other wireless networks.

Here we make use of an interface of Zigbee with Raspberry Pi2 for a proper wireless communication. Raspberry Pi2 has got four USB ports, so it is better to use a Zigbee Dongle for this interface. Now we want to check the communication between the two paired ZigBee modules.
Modules Needed :

Raspberry Pi2
XBee 1mW Wire Antenna- Series 1 (2 No:)
XBee Explorer Dongle (2 No:)

The two Zigbee must be paired with the same baudrate (for Ex: 9600) with X-CTU Software. Attach the two Zigbee’s to the two dongle’s and connect one pair on the USB port of the Raspberry Pi2. Connect the other pair to the USB port of a computer or a Laptop. Install the FTDI Driver on the Computer /laptop to provide usb communication. Create a hyperterminal, select the corresponding com port and the baudrate for the connected device.

FTDI Virtual Com Port(VCP) driver Installation

Many embedded devices communicate over the serial port connection as most modern computers lack a hardware serial port; USB adapters provide the serial interface. Here we are discussing how to open a serial connection to an embedded device on Windows XP.

The FTDI makes USB communication with a micro controller or serial device .The chip on the board translates the serial data coming from a device into USB data and vice-versa. It is widely used to upload firmware to the Various development boards, but it can communicate with any serial-enabled device

The CDM driver provides access to virtual COM port (VCP).If you plug in your FTDI device, your computer will not immediately recognize it. In order to function with a terminal program, the FTDI requires special device drivers. The drivers for various operating systems can be found on the FTDI website. The particular driver one needs is Virtual COM Port, or VCP. It allows the USB device to appear as a COM port to be used with a terminal.

Download the latest available CDM drivers from the FTDI web site and unzip them to a location on your PC

How to Install
Connect the device to a spare USB port on your PC. If the device is based on the FT2232, the Microsoft composite device driver is automatically loaded in the background and a little popup bubble in the bottom right corner of the screen that says Found New Hardware FT232R USB UART.

After a few seconds Windows Found New Hardware Wizard will launch

Select “No, not this time” from the options available and then click “Next” to proceed with the installation.

At the next screen, Select “Install from a list or specific location (Advanced)” as shown above in Figure and then click “Next”

Select “Search for the driver in these locations” and enter the file path in the combo-box (“C:\CDM 2.02.04″ in Figure or browse to it by clicking the browse button. Once the file path has been entered in the box, click Next to proceed.

If Windows XP is configured to warn when unsigned (non-WHQL certified) drivers are about to be installed, the message dialogue shown in above Figure will be displayed unless installing a Microsoft WHQL certified driver. Click on “Continue Anyway” to continue with the installation. If Windows XP is configured to ignore file signature warnings, no message will appear.

It should copy some required driver files and installing the software, then come up with this window display a message indicating that the installation was successful Click “Finish” to complete the installation for the first port of the device.

If the device is based on the FT2232 almost immediately, another window will pop up; this time it will say USB Serial Port. As before, click Install from a list or specific location. The procedure for installing the second port is identical to that for installing the first port from the first screen of the Found New Hardware Wizard.

The Found New Hardware Wizard will again launch automatically to install the COM port emulation drivers. Select “No, not this time” From the options and click “Next” to proceed with the installation.

Select “Install from a list or specific location (Advanced)” and then click “Next“.

Browse to the same folder again and click Next to proceed.

Again the warning message will pop up,If Windows XP is configured to warn when unsigned (non-WHQL certified) drivers are about to be installed, the message dialogue shown in above Figure will be displayed unless installing a Microsoft WHQL certified driver. Click on “Continue Anyway” to continue with the installation. If Windows XP is configured to ignore file signature warnings, no message will appear.

The below screen shown will be displayed as Windows copies the required driver files.

Now the required device driver is installed, you may need to reboot the computer.

Connect your FTDI device to a spare USB port on your PC,Now a popup bubble in the bottom right corner of the screen that says Found New Hardware USB Serial Port.

OK now you can verify that the driver installed properly..
Right Click on the my computer Icon in the Desktop click Manage (Open start=>run=>compmgmt.msc) then come up with this window.

Click on the Device Manager Button Look for an entry under Ports (COM & LPT)

It shows USB Serial Port (COM) the COM number may vary but it should be something like COM3 or COM4 the COM number may be as high as COM99 so just look for the USB serial port. The COM stands for “communication”, and each one has a unique number, known as the COM Port number. In this case the COM Port number is COM4. If you don’t see the COM port, verifies the cable is plugged in, and check that VCP FTDI driver is installed.

Right click on the selection then click on properties the above window is come up and here you can change the port setting.

XBee Explorer Dongle

Testing xbee:

XBee Explorer board with USB A Type connector for the XBee line of products which can be used as Dongle – can avoid USB cable and LAPTOP friendly!! . The board is populated with high current LDO to support most of XBee modules including XBee Pro! .The XBee Explorer Dongle will help you to reduce lot of hassles normally facing to implement Xbee Network.We have also added two more LED’s (SLEEP & Associate) apart from normal 4 LED. This help you to use latest versions XBee Modules as well. The module is self powered from USB Port itself, thanks to low dropout regulator.

After Power up the explorer Dongle board will create a virtual COM port in PC , and you can communicate with the module same as serial port devices. The Explorer board is built with FT232RL Chip from FTDI and drivers are available for Windows ,Linux and MAC.
This unit works with all XBee modules including the Series 1 and Series 2.5, standard and Pro version. Plug the Xbee Module into the XBee Explorer Dongle , attach to the LAPTOP, and you will have direct access to the serial and programming pins on the XBee unit.

Features:

USB A Type Connector
Built in SMD fuse for protecting PC USB Port
Powered from PC USB Port
High Current (500ma) 3V3 Voltage Regulator for XBee/XBee PRO Module
5 Onboard Status LEDs (Associate,Sleep,Tx,Rx and RSSI)
Onboard Power LED
High qualty PTH PCB and made by Automatic Pick and Place Machine

Specifications:

PIN Diagram:

PIN descriptions are given below:

Layout:

How to Test:

Test your XBee Explorer Dongle with PC:

When XBee Explorer Dongle is connected with USB port of PC,the PWR (blue) LED will glow on the top of module ,it shows power indication.

For a quick installation on XBee Explorer Dongle and connection details please read the blog…
Here we are using a paired Zigbee, to construct a simple point-to-point network.One of the devices must be a Coordinator and the other must be a Router (an ‘endpoint’ device).
After completion of installation setup SLP LED(Green) is turn ON and also ASSOC LED(Red) will blink rapidly 2 times per seconds(Association Confirmation received to the endpoint device from the Coordinator) or ASSOC LED will not blink if the End Device has not associated.
During the transmission TXD led blinks as per the data rate and at the time of reception RXD led blinks.
RSSI LED(yellow) on top of the board is connected to the RSSI (Received Signal Strength Indicator) pin of the XBee module. XBee outputs a PWM signal on this pin which is directly proportional to the quality of the RF signal, until the last packet was received by it. This PWM signal applied to the RSSI LED will vary its brightness as per the quality of the RF signal,better the RF signal brighter the LED.

Here below one example is shown:

Placing XBee module on XBee Explorer Dongle is shown below.

In this example we are making communication between two paired zigbee COM PORT of coordinator zigbee is set in Hyperterminal and wrote a message like here it is “Hai Xbee connected” sent it to end point Xbee.

And we opened other terminal window i.e realterm and COM PORT set in realterm terminal window is of End point Xbee and received message sent from coordinator Xbee in realterm.Click here to download realterm.