1. Electronics and Networks: Week 9: Dumb things without Wires RF / IR Communication Jonah Brucker-Cohen Matthew Karau Monday 10am - 12pm Trinity College Dublin MSc. Multimedia Systems Spring 2003

2. Reading: Artistic Practice in the Network Networks, Bodies, Symbols Katherine Hayles - “Bruno Latour’s “quasi-object” animate vs. inanimated object (instead a single category) Accessories Yukiko Shikata - extending the self wireless devices - become extensions of our personality Urban Spaces Knowbotic Research - looking at urban spaces and manifesting their activity in a shared installation both physical and web-based Simple Networks Victor Vina - BOX project - Connected open system Any Thoughts?

3. RF /IR Communication What is RF/IR Communication? RF Comm: Types How can we use it? Examples What has it been used for?

4. IR = Infrared Radiation Examples of IR devices: Remote Control (TV, Stereo) Handheld Devices (Using IrDA protocolo to send messages - Palm, Mobile Phone) Sensing devices (breaking beams,burglar alarms) What is IR Communication?

5. RF = Radio Frequency Radio Wave = Electromagnetic wave with different frequencies Radio Receiver = Tuning to a specific frequency you can pick up a specific signal. FM Radio = example 91.5 megahertz AM Radio = example 535 kilohertz Examples of bands: AM radio - 535 kilohertz to 1.7 megahertz Short wave radio - bands from 5.9 megahertz to 26.1 megahertz Citizens band (CB) radio - 26.96 megahertz to 27.41 megahertz Television stations - 54 to 88 megahertz for channels 2 through 6 FM radio - 88 megahertz to 108 megahertz Television stations - 174 to 220 megahertz for channels 7 through 13 What is RF Communication?

6. Examples of other bands: Garage door openers, alarm systems, etc. - Around 40 megahertz Standard cordless phones: Bands from 40 to 50 megahertz Baby monitors: 49 megahertz Radio controlled airplanes: Around 72 megahertz, which is different from... Radio controlled cars: Around 75 megahertz Wildlife tracking collars: 215 to 220 megahertz MIR space station: 145 megahertz and 437 megahertz Cell phones: 824 to 849 megahertz New 900-MHz cordless phones: Obviously around 900 megahertz! Air traffic control radar: 960 to 1,215 megahertz Global Positioning System: 1,227 and 1,575 megahertz Deep space radio communications: 2290 megahertz to 2300 megahertz What is RF Communication? Con’t

7. Transmitter/Receiver Separate modules for each function (IR, RF) Example - r/c car - controller and receiver on car IR Example: remote control toy Transceiver One module for both functions - transmit and receive (example mobile phone) IR Example: PALM Pilot, computer port Half-Duplex Mode Data can move in two directions, but not at the same time (example walkie-talkie watch) Full-Duplex Mode Data can move at the same time in two directions (example telephone, serial, mobile phone, LAN, Infrared) RF/IR Communication: Types Full-duplex diagram Half-duplex transceiver Half-duplex transmitter/receiver

8. RF is great for simple wireless applications Replace a serial cable with a wireless module/ IR beam to work away from the computer Be careful about ranges! Most wireless serial transmitters have limited range (around 300 feet/90 Meters) / IR 3 ft - 3 inches Local Devices (Questions?) What are advantages of not being tethered to a computer? What relationships exist between information and context? What does wireless add to electronics and networks? RF/IR: How can we use It? Glolab RF Modules www.glolab.com RadioMetrix Transceiver www.radiometrix.co.uk

9. Connecting IR Transmitters/Receivers to Basic Stamp II Example using 555 timer IC IR Communication: Schematics

10. RF /Infrared: What has it been used for? 2 Project Examples One2One - wireless flower Flower connected to wireless receiver, gets signal from computer and blooms when user’s girlfriend/boyfriend is online Transparent Headphones - IR communication IR sends distance info between Two pairs of headphones

11. Hacking an RC Car Transmitter with a Basic Stamp II RF Communication: Schematics