Wireless for the Internet of Things

Gerard Borg

Research School of PhysicsCollege of Engineering and Computer Science

Australian National University

http://users.cecs.anu.edu.au/~Gerard.Borg/anu/teaching.html

Electromagnetic WavesFrequency - MHz, Wavelength – meters

Frequency x Wavelength = 3 x 108 m/s (?)

Frequency = f, Radian frequency = 2pf , Wavelength = l

88-108MHz 520 820MHz477MHz

AM radio

1MHz

CB radio

148MHz

Amateur radio

VHF TV

150-152MHz 915-928MHz433MHz

Antennas

Antennas

Radio Astronomy

Antenna maths

Antenna summary

Friis transmission

Raspberry PI

Raspberry PI add-onse.g. Sensehat

Software Defined Radio I

Software Defined Radio II

https://osmocom.org/projects/rtl-sdr/wiki/Rtl-sdr

RTL-SDR Schematic

RTL-SDR Under the hood

RF Coaxial connectors

Put them together...

What can we do? IoT, experiment, have fun

Weak Signal Propagation and Reporting Network (WSPR)

http://users.cecs.anu.edu.au/~Gerard.Borg/anu/projects/amateur/wsprnet/wsprnet.html

It's aim is to encourage experimentation and technical development among clubmembers in the area of high-altitude balloonpayload development.

Conclusion

Signal Blocks 1bandpass filter

Signal Blocks 1mixer