Hi Martin!
Finally I got some more time to test. I have made the amplifier and have a nice clean sinal out to the input to the Pic.
I know your program work, anyway when I connect my generator to the input, I have same result in the display as you. But when I test with the radar connected, I see the speed in the display, but it is not stable and fluacting up and down if I walk speed between km/h 2 - 16, sometimes I feel I see the correct speed.
Honest, I don´t understand your program 100% (me the dummy

) But the signal which come in are not stable, should it the not be caltulate the average frequense in someway or?
I have Google the HB100 and found on youtube this
https://www.youtube.com/watch?app=desktop&v=uSma0zQSnsU
I try to att. his project here but to big. It can downloaded here:
https://www.dropbox.com/s/7d1fdzr8d243n ... 2.zip?dl=0 May be you can see if it is some similar to your program.
Of course I could use his program/project, but I will prefeer Flowcode.
If you not have time to look at it I understand, but dare to ask ayway
Thank´s in advance.