Hello, I use a square wave to generate control/clocking signal for some control logic:
https://snipboard.io/WQ8p6d.jpg The work function of the "Controller" block looks like: def work(self, input_items, output_items): d = np.diff(input_items[0]) inds = np.where(d == 1) for ind in inds[0]: nedge = self.nitems_read(0) + ind delta = nedge - self.nedge_prev print("EDGE @ " + str(nedge) + ", Delta=" + str(delta)) self.nedge_prev = nedge return len(output_items[0]) I.e., it detects the rising edge. The code above stores the previous edge and shows the delta between them. If the frequency of the square wave exactly divides the sampling rate, I would expect that this delta is always constant/consistent (and I need this for my application). However, with samp_rate=5M and freq=10: EDGE @ 10751169, Delta=500054 EDGE @ 11251224, Delta=500055 EDGE @ 11751278, Delta=500054 EDGE @ 12251332, Delta=500054 EDGE @ 12751387, Delta=500055 EDGE @ 13251441, Delta=500054 EDGE @ 13751496, Delta=500055 EDGE @ 14251550, Delta=500054 One interval is not only not always constant but is 54/55 samples larger than the expected 500000. When making the interval small (e.g., samp_rate=5M, freq=1k, it works: EDGE @ 65072534, Delta=5000 EDGE @ 65077534, Delta=5000 EDGE @ 65082534, Delta=5000 EDGE @ 65087534, Delta=5000 EDGE @ 65092534, Delta=5000 EDGE @ 65097534, Delta=5000 EDGE @ 65102534, Delta=5000 I tried tried offsetting the frequency by a slight but but no change. E.g., freq = 1.0 / (1.0/10 - 1.0/samp_rate) I know I could implement a logic that adds a constant directly in the work function but to keep things manageable I would really prefer to use clock signals (there will be a bunch of them floating around in the end). Thanks, Lukas