First off, this is Sam May and Peter Oliver's ELEC3117 project. By reading this you agree to never use any original material in a UNSW course we will formally accuse you of academic misconduct and take your fucking plagiarising arses down with the wiki edit logs. Feel free to use this stuff for a personal project though.

Game Concept Edit

Each team takes turns to hide their flag somewhere in the playing landscape. The teams are then given a proximity detector that will intercept transmissions emanating from the enemy flag. The proximity detector will beep and flash at a frequency inversely proportional to the distance from the flag (i.e. fastest when very close to the flag). In this way, the proximity detector can be used to locate the enemy flag. The first team to wave their enemies' flag is the winner.



Pete: Project description and market analysis. Sam: executive summary, conclusion, cost estimates, development plan.

Conceptual Design Edit

The flag emits a signal which is received by the proximity detector. The proximity detector verifies that the signal was sent by the enemy flag and then sets the frequency of beeping and flashing based on the signal power received.

Transmitter (Flag) Edit

In a noisy environment, we believe that amplitude-shift keying (ASK) would be the best choice of modulation. 'n' pulses are generated every 't' seconds by the pulse generator which is then modulated onto a carrier wave of about 27 MHz. The signal is then amplified and isotropically radiated into space. The power supply will be battery supplied and will require both a digital output for the ASK generation and an analogue output for the amplifier and transmitter circuits.


Receiver (Proximity Detector) Edit

There are two streams in this diagram. The first is to verify that the signal being processed is coming from the flag and not some other environmental source. If this is confirmed the other stream becomes active, which communicates to the user, the proximity of the flag.

The antenna receives energy from the environment and then the receiver selects the appropriate carrier frequency. The demodulator removes the carrier wave and leaves the digital signal. The counter then counts the number of pulses. If 10 pulses out of 16 are detected, this verifies that the correct signal is being processed and the "beep frequency enable" supplies the logic to enable the other stream. The counter will time out after a given time.

The averager rectifies averages the incoming signal, with the voltage output being proportional to distance from the source. This voltage is then converted in the "signal power to frequency" to a frequency, which is supplied to a timing circuit inside the "sound/light circuit" block. The sound/light hence is able to create two signals that beep at a frequency inversely proportional to distance. A tone is generated and amplified in the sound circuit.


Design Specification Edit

Operating Range 10 kms
Resolution 10 m
Transmitter Batteries 4 x D
Receiver Batteries 1 x 9 volt

Design Implementation Edit

Performance Testing Edit

PCB Layout Edit

Parts List Edit

ICs Edit

1 x NE555P timer

3 x DM74LS161AN 4 bit counter

1 x SN74HC132N Quad NAND

Passive Components Edit

1 x 1 nF greencap

1 x 10k Ohm

1 x 680k Ohm

1 x 39k Ohm

1 x 2.2k Ohm