SDR Duck Hunt

Background

While Fox and Hound activities are fun, they’re also seemingly simplistic: find the transmitter. In the SDR Duck Hunt, a player not only has to find the transmitter, but also exercise knowledge of radio communications to transmit back to then receive their points. Using the right antenna, filters and transceivers, a player will be very successful in finding, shooting and collecting their virtual ducks.

Here on in, the following terms are synonymous:
Antenna and Transceiver – Shotgun
Duck Calls – The Beacon
Shooting – Transmitting “BANG”
Duck – You hash to use for points

How to Play

Warm Up

1. Take your shotgun to the Wireless village, and test to make sure you can shoot the practice ducks. Meaning, bring your directional antenna and transceiver and test to make sure you can detect and interact with the practice duck.

Get your Hunters License

1. Find one of the staff members and prove to them that you are properly licensed by the FCC or equivalent authorities. You will sign in, and a hunters license will be issued to you.

In the Fields of Glory

1. Explore the conference listening for the duck calls. They should happen once every three seconds.
2. Feel free to corner, distract or engage in conversation with the ducks. Shoot at them. But shoot too often, and they will fly away for 5 to 10 minutes.
3. Receive the duck, it’ll be an MD5 hash. One duck per hour.

Poaching

1. Be wary of poachers; someone else can steal your duck without needing a license.

The Duck

1. The duck is constantly listening on a fixed frequency.
2. It is using a mis-matched antenna system for receive; this is why you have to use a directional antenna to be successful. Think of it like changing the chokes on your shotgun.
3. You will hear the dog laugh at you if you shoot too frequently on the same frequency that the ducks quack on.
4. It would be easier as a team effort; one person shoot, while the other tries to collect the duck.

Technical Requirements:

1. The BANG and duck hash are transmitted via AFSK. Each time the contest is run, there are slight and minor changes to the AFSK encoding. But pay attention and test, you should be fine.
2. You can use a RaspberryPi that supports PiFM and a RTL-SDR, or a HackRF, or pretty much anything within the operating frequencies of the context.

If you were to want to shoot aimlessly into the sky, a command such as the below would achieve that if you were using a RaspberryPi to transmit with PiFM:

#!/bin/sh
while true ; do echo "bang" | minimodem --tx -f -8 1200 -f /home/pi/bang.wav && /home/pi/pifm /home/pi/sentence.wav 80.0 48000 ; sleep 4;done

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