Components Sheet

PDF file in Google Drive

Picture below:

Please be noted that the shopping basket dosen't include a XBee Explorer USB  which I can only find on Amazon in uk. Also components like breadboard, resistor (4.7K), and jump wires are not included.

 

The XBee Explorer USB can be found here: http://www.amazon.co.uk/Wireless-Xbee-WRL-08687-Explorer-USB/dp/B008FZJHQK/ref=sr_1_1?ie=UTF8&qid=1355414228&sr=8-1

Project Preview

This project is about using IEEE 802.15.4 standard to establish a wireless sensor network. In this project title, there are two words which is important to understand their meanings, it is IEEE 802.15.4 standard and the wireless sensor network.

IEEE 802.15.4 standard is a kind of network connecting standard which is used in low-rate wireless personal area network. IEEE 802.15.4 standard restricts a low energy consumption, low transmitted rate and low cost network transmit method which can connect some devices within a family or individual.

Wireless sensor network, the elfevident, is a network built by a deal of sensors connected to each other by using the wireless method. This network mainly contains three members, sensor nodes, sink noble and Management Node. However, sensor nodes and sink noble may be more necessary which should be covered in the project. Sensor nodes are used to get information which should have memory and the ability to send information wirelessly. Sink noble should have the ability to get, store and process information.

Such network and IEEE 802.15.4 works like, when the sensor nodes get the information they send the information to the sink noble, then, sink noble should do some basic information processing and send it to the radio modem which is connected to the PC. During the transmitting process IEEE 802.15.4 standard will take care of it and unify transmission mode.

Consider a more specific state, to realize the network and the whole system we should have some sensors which can not only get the information but also send them wirelessly. A radio modem over a microcontroller should have the ability to get the information and send them to the microcontroller, this microcontroller will deal with the information and send them back to the radio modem after processing them. The radio modem should will send the information to the other radio modem which connected to some computers. The Xbee, from the professor’s link, is a kind of radio modem, which can work in pairs. This radio modem is only an end-point which means it does not have any ability to process the information. As a result, the microcontroller and PC will be the information processing center to process all the results.

Group 70

Zhiqing WU

Project Understanding

Wireless sensor networks using the IEEE 802.15.4 standard

 

IEEE 802.15.4 standard: There are many task groups under the IEEE 802.15 working group. The first standard 802.15.1, also known as Bluetooth, is developed by the first task group and the standard 802.15.4 is maintained by task group 4.  IEEE 802.15.4 focuses on low-rate wireless personal area networks (LR-WPANs) and is operating in the industrial, scientific and medical (ISM) radio band. It allows 27 channels separated in 868.0-868.6 MHz, 902-928 MHz and 2400-2483.5 MHz; developers can select one channel by considering the data transfer rate in the network and the band congestion.  The standard provides long battery life, short distance, low energy consumed and low cost wireless sensor network solutions which can be used in lots of monitoring and control applications, for example, intelligent home system or interactive toys.

 

XBee 802.15.4 module: There are two versions of this module, XBee and XBee-PRO. The indoor/urban working range of XBee is 30 meters so XBee is enough for this project. The RF Data Rate of XBee is 250kbps and the transmit power output is 1mW. It operates in the unlicensed, international frequency band ISM 2.4 GHz so there are 16 channels to choose by software. XBee supports point-to-point, point-to-multipoint and Peer-to-peer network and in this project it will be a point-to-point network. XBee has 20 pins in two rows so the interface boards should have two 20-pin receptacles to receive the module. The supply voltage of XBee is 2.8 – 3.4 Volts.

 

Microcontroller: It is used to receive, send and processing data in this wireless network. For example the group can use Arduino board which consists of an 8-bit Atmel AVR microcontroller. There are lots of models of Arduino board and the group should choose a model has USB transceiver to connect with the XBee through a USB interface. I am not sure if there is a microcontroller board can connect directly with Xbee which is convenient and concise, at present I found a XBee Shield which can mate directly with an Arduino board. The project also needs some programming work to make the components cooperate well.

 

2012/12/12

Liang Xiang

Uol Y2 Project