GNU Radios

GNU radios

In NITOS testbed 6 of the Commell nodes are connected with GNU Radio boards (software defined radios), specifically USRP1 boards with XCVR2450 daughterboards (2.4-2.5 GHz and 4.9 to 5.85 GHz Dual-band Transceiver) from the Ettus Corp.

GNU Radios allow the researcher to program a number of physical layer features (e.g. modulation), thereby allowing for dedicated PHY layer or cross-layer research.

Usefull Infomation about GNU radio can be found on the official gnuradio.org site. We recommend users who intend to get involved using software defined radios to read first FAQ about Gnu Radios. It will help them resolving many queries. Also the datasheets about USRP1 and XCVR2450 daugtherboards can be found on link1 and link2 respectively.

Below some photos of USRP1s deployment in NITOS testbed are illustrated.

USRP1s  assembled with XCVR2450 daugtherboards, ready to be attached on nodes

USRP1 with XCVR2450 daugtherboard, attached on a NITOS's testbed Commell Node

NITlab Chassis Manager Card old version

NITLAB designed and implemented a Chassis Manager(CM) card to control and monitor NITOS nodes. CM card is comprised of a general-purpose microcontroller, an ethernet microcontroller and a relays circuit. General-purpose microcontroller supports a tiny web server and can serve http requests such as power on/off and reset. Furthermore, it returns the operation status of the node and can support a temperature & humidity sensor and a light sensor as well.

It should be highlited that the developed CM Card is based on the open-source AVR microcontroller board provided by tuxgraphics. Tuxgraphics also provides a basic firmware with a WebServer implementation through which is feasible to control remotely microcontroller's I/O pins.

You can watch a demonstration video here.

Prototype Technical Information:

• AVR micro-controller ATmega328P
• Ethernet Controller with SPI Interface ENC28J60
• Ethernet Magjack
• 2 reed relays
• CM card's firmware

Relays Circuit Schematic (designed and implemented by NITlab):

This circuit is been implemented on the empty edge of CM card and is been connected with the microcontroller.

Microcontroller Circuit Schematic (as provided by tuxgraphics):

Temperature & Humidity sensor:

Light sensor:

More photos:

iRobot Nodes

NITOS team has made mobile nodes using "iRobot Create" with a custom designed tray to hold the system board. The board is an "Alix Board" of  "PC Engines" company . Commands are sent to the robot over a serial port and the whole system is powered from the robot’s battery. The upward facing camera is used to recognise specific patterns on the ceiling, which help the robot navigate around the room.

To fully construct the mobile nodes the following hardware parts were used:

• 1GB compact flash memory card as a hard disk

• A custom made transformer from 220V AC to 110V DC to achieve charging.

• Alix Board as mentioned above was used and powered using the Create's battery. iRobot gives access to the Create's battery through the 25-pin cargo bay connector.

• Logitech QuickCam.

The Alix board runs Voyage Linux. For moving the robot, an implementation in python of the iRobot Create Open Interface was used, called openinterface.py. For the pattern recognition ARToolKit was used, a software library for building Augmented Reality (AR) applications.

You can also see iRobot in action here and more information here.