I'm using the PiGPIO library to receive a waveform but I don't see a way to make sure the RF frequency is correctly set. I'm using the class rx() which is supposed to read a signal transmitted on 433 MHz, but I'd like to change this value. I've search in pigpio.py but couldn't find it.

  • Welcome to Raspberry Pi SE. Please take a look at raspberrypi.stackexchange.com/Tour to see this site's recommendations for the format of questions. In this question it would be useful to understand your hardware configuration as well as the software you are using. I see the library is named, and piGPIO is great. But it will require more information in order to attract the most useful answers.
    – SDsolar
    Apr 16, 2018 at 0:37

1 Answer 1


pigpio doesn't read the 433 MHz signal. The signal is picked up by the wireless receiver hardware which passes on 1s and 0s to the Pi. You get a 1 while the 433 MHz carrier is present and a 0 otherwise.

The actual radio frequency is irrelevant to pigpio, that side of things is automatically handled by the transmitter/receiver pair.

  • I thought the hardware may have a bandwidth and we could somehow select a frequency within that...if not, I guess it's going to be difficult to receive something "clean", as I'm not receiving anything that makes sense
    – itd
    Apr 16, 2018 at 10:39
  • I have only used inexpensive receiver/transmitter pairs (a few UK pounds). The receiver will pick up static with lots of false signals until the transmitter is sending. Connect up your receiver and view with piscope. Set a glitch filter on the receive GPIO of perhaps 100 micros or so increasing until little static is seen (pigs fg 4 100 if using GPIO4) and then transmit something.
    – joan
    Apr 16, 2018 at 11:04
  • I'm not able to record my signal properly: tried a glitch of 50, then 100, then 150, 200... but it looks like it's not getting all the sequence and I think it's because of the center frequency. I was trying to use GNURadio and a RTL-SDR dongle but apparently GNURadio doesn't work on the Pi
    – itd
    Apr 16, 2018 at 14:26

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