rpitx

https://github.com/F5OEO/rpitx You don't need much to spam random RF energy into the air. That project just flips a GPIO pin at the right frequency, and gets a signal into the air. It won't be very powerful, and the harmonics will probably bleed all over the place if you just hang a wire off of it with no filters.....

You think that's fun, rpitx will blow your mind: https://github.com/F5OEO/rpitx

Not at all: https://github.com/F5OEO/rpitx/blob/master/doc/Tunerpitx.png

This is just a slopped version of https://github.com/F5OEO/rpitx This stuff shouldn’t be on HN.

This is very bad. No filtering, all transmissions on harmonics. Emotes in readme, emotes in scripts, emotes in source files, lol libs used = LLMed up the ass. Someone pointed Claude (yes, CLAUDE.md is in the repo) at https://github.com/F5OEO/rpitx and told it to wrap it around in fluff go code, then sprinkled profanities and pirate theme on top.

One doesn’t actually need any extra hardware for this… just 8cm of wire and this https://github.com/F5OEO/rpitx (use at your own risk of course)

You can broadcast FM radio over short distances by doing PWM over GPIO pins, so that does not suprise me! I used this for switching radio controlled power outlets which had 433mhz receivers. [2] [1] https://github.com/markondej/fm_transmitter?tab=readme-ov-fi... [2] https://github.com/F5OEO/rpitx

As someone with a HackRF PortaPack knockoff I got from ebay, I would agree that SDRs are better and cheaper than ever before. However, I think the average person will struggle with using a HackRF for more complex projects. I've used URH before, and while useful, it can be intimidating for beginners. Also, while I like the RTL-SDR (and the price tag!), you can't transmit with it. While this isn't a deal breaker to everyone, if you'd like to clone a garage door remote, for example, you need to be able to transmit. While you could use something like a raspberry pi and rpix [0], but I think it is more work than it's worth for many. Also, multiple RTL-SDRs are required for higher bandwidth applications like ASTC TV or trunked radios. With the flipper, I think the main draw for most is the point-click-done nature. Include the Android/iOS app an

HackRF One is an option. There are a number of others. Legality varies by country/frequency/power level. Can also make a Raspberry Pi act as a transmitter (https://github.com/F5OEO/rpitx), which could hit the zwave frequency but not the zigbee one. (Also, make sure to put a low pass filter on it.)

See https://github.com/F5OEO/rpitx

RPITX is the spiritual successor of your project! https://github.com/F5OEO/rpitx And it does work with nearly every RPi. And unlike only doing FM (97MHz-108MHz), it can emit from an IQ datastream from 10KHz to 1.5GHz.

There are also cheap SDR transmitters: https://osmocom.org/projects/osmo-fl2k/wiki (repurposing a USB-VGA dongle as analog source) https://github.com/F5OEO/rpitx (repurposing bitbang/PWM GPIO; we had weird problems with data corruption when we were trying to use it as a radio modem, but maybe you will have more luck) https://bellard.org/dvbt/ (repurposing standard VGA card, but it's probably not worth it since fl2k is way better) (beware that low quality of the transmitter usually means it will cause interference with other stuff. However, all of these have such a low power that if you will not use an amplifier, it will be OK, the interference will be probably undetectable outside of the room where the transmitter is)

Unfortunately the article does not provide an explanation how the GPIO transmit function was achieved, but most probably it was based on prior art here: It started with piFM [1] where the possibility was explored to modulate the internal PLL Raspberry Pi with FM and output it on pin GPIO4. This was then further refined and a PWM phase and amplitude modulation technique was applied which made it possible to generate SSB signals [2]. Based on this rpitx [3] was then created which made it possible to basically modulate any type of signal, enabling to use a raspberry pi for analog and digital broadcasts, and to replace key fobs for RF smart plugs and other wireless devices. So yes, it is possible.. [1] GPIO4 piFM transmitter, by Oliver Mattos and Oskar Weigl http://www.icrobotics.co.uk/wiki/index.php/Turning_the_Raspb... [2] Direct SSB genera