Abusing Raspberry Pi GPIO pins as a radio transmitter to control my ceiling fan

In Part 1, we covered capturing and decoding the remote control's signal using
a USB TV tuner: • Hacking My Ceiling Fan...
In Part 2, we take use a Raspberry Pi's GPIO pin as an antenna to transmit our
own signals to the ceiling fan.
rpitx: github.com/F5OEO/rpitx
The ceiling fan / light combo I have is Minka Aire brand. I think most of the
different ones on the market work pretty similarly.
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Parts:
rpitx lists the Raspberry Pi 4 as having "beta" support. (I used a Raspberry Pi 3B.)
Sparkfun: www.sparkfun.com/products/14643
Adafruit: www.adafruit.com/product/3055
Amazon: amzn.to/3crvFFI
I found my low-pass filter on eBay (overseas shipping). Digikey has low-pass
filters that would also work, but not as cheap.
eBay low-pass filter: ebay.us/4cSPe5
eBay SMA antenna: ebay.us/GcL9qa
eBay SMA connector: ebay.us/PGPmGM
Note that these all have SMA connectors, not RP-SMA (which look very similar).
Also note that eBay listings come and go, so double-check that you get
compatible parts. The antenna does not need to be exact - the one I got is
listed for 315 MHz and works just fine.
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Background music:
Aerosol Of My Love by Kevin MacLeod
Link: incompetech.filmmusic.io/song...
License: filmmusic.io/standard-license
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