Hi I have the following flowgraph: Noise source -> Throttle -> Stream to vector (Num items=1024) -> FFT (FFT size=1024) -> Complex to mag^2 -> Moving average -> QT GUI vector sink In 'Moving average' the parameters are: Length = n_average Scale = 1.0 / n_average Max iter = 4000Length of vectors = 1024 To give a value for the parameter 'n_average' I have a 'QT GUI Range', with the following parameters: ID = n_average Default value = 9Start = 2Stop = 10 Step = 1 If the 'Default value' above is 8, 9 or 10, I can change the value of 'n_average' to any value between 2-10 when the flowgraph is running, and everything works fine.
However, if the 'Default value' above is between 2-7, then always when I change the value of 'n_average' to 9, the flowgraph freezes (GUI vector sink is not updated anymore). There are no error messages. If I change the value of the 'Stop' parameter to 100, the same happens when 'n_average' is changed to 9, but if I change 'n_average' to e.g. 62, I get an error message like 'gr::log :ERROR: block_executor - sched: <block moving_average (5)> is requesting more input data than we can provide. ninput_items_required = 62 max_possible_items_available = 15 If this is a filter, consider reducing the number of taps.' I am using Gnu Radio Companion version 3.9.5.0 (Python 3.8.10) in Ubuntu 20.04.4 LTS. GRC has been installed by using PPA installation. cheers, Kimmo