Goals

• Show how I approach problems/tasks
  • Research
  • Plan
  • Execute
  • Iterate

Research

• No HW yet
• What is an SDR?
• What is GNU Radio?
• What is GRC?
• What is my game plan?

Game Plan

• Explore GNU Radio
• HW bring-up
• HW + GNU Radio (hello world)
• Decode something
• Make presentation

Explore GNU Radio

• Check repos: "apt search gnu radio"
• Install: "sudo apt install gnuradio"
• Run through some simulation tutorials

HW bring-up

• dmesg
• lsusb
• rtl_fm -> play
  • http://kmkeen.com/rtl-demod-guide/
  • K99.1FM
  • sudo apt install rtl-sdr sox

rtl_fm -f 99.1M -M fm -s 170k -A fast -l 0 -E deemp | \
play -r 170k -t raw -e s -b 16 -c 1 -V1 -

HW + GNU Radio

• FM radio: https://www.instructables.com/id/RTL-SDR-FM-radio-receiver-with-GNU-Radio-Companion/
• apt search rtl gnuradio
• sudo apt install gr-osmosdr
• Rational resampler data type needed to be float (doing tutorial paid off)

YN560

• 2.4HGz FSK - Nope!

APRS

• 144.390MHz - Yes....
• Gqrx - nada
• Baofeng - no problem
• Antenna?
• Miss-information?
  • 24MHz - 1850MHz
  • 87.5MHz - 108 MHZ ?!
  • 25MHz - 1700MHz ?!?!
• Confirmation: 147.045MHz (W8DGN) static!!!!

RDS

• Seems safe freq-wise
• Research: https://en.wikipedia.org/wiki/Radio_Data_System
  • Not going to be able to acomplish in a reasonable time frame

Lamp remote

• FCC: https://fcc.report/FCC-ID/PAGTR-009-1
  • freq: 315MHz
  • bandwidth: 80.8kHz
  • modulation: ASK
• Believe it's OOK/CW

Learned

• Modulation AM, FM, FSK, ASK
• IF
• GRC, GNU Radio, Gqrx
• Some reverse engineering
• Little smarter each attempt
• Easy to get discouraged
  • Experience has taught me this usually precedes the breakthrough

Going Forward

• Grok it!
• Better antenna
• Better placement (remote control via Beaglebone)
• Local repeater activity tracker?
• Spy water, gas, electric meter?
• Garage door remote extra buttons?

Code Samples

• StdInt
• Nill
• gapt-get
• piny
• Pandoc+Make=website
• coroutines - Can't take the credit but soooo cool!

Demo

Questions