Very cool, it already had a impressive battery life to begin with. I just used my son's zero to debug a ceiling fan remote.

Of course he uses it to turn off TV's and open Tesla charge doors..

Which ceiling fan remote? I've been fighting with our bedroom fan, we like the performance but the remote works maybe once out of every 100 presses unless I climb up on our bed and extend my arm into the middle of the fan housing.

I went into the weeds of reverse engineering my Minka Aire ceiling fans with a USB RTL-SDR. In my case the manufacturer's remotes worked fine, but I wanted to integrate it in with Home Assistant. If you're interested, you can see what I did: https://www.riveducha.com/decode-wireless-signal-with-usb-tv...

I used a USB RTL-SDR ($15) and a Raspberry Pi to receive and transmit, but I think the Flipper Zero can do it all-in-one.

What $15 USB SDR can transmit? All the ones I have only receive, and to transmit I'm seeing more like $100. At $15 I would buy one immediately.

I think people have managed to use the GPIO pins as a bit bang transmitter.