I have just posted a major update of my filter design tool. Go to the tool. In addition to low-pass and high-pass filters, it can now also design band-pass and band-reject filters. The new version of the tool allows you to change the sampling rate away from the default of using normalized frequency (but beware of the caveats). Finally, you can also change the window (but the default is still Blackman). At this time, the tool is still limited to the (very basic) design method from the mentioned articles, so its main usefulness is still educational.
Figure 1. Filter designer.This new version of the filter designer, and the tomography tool that I am also preparing, go a long way towards explaining the recent drop in my posting frequency… But I’m preparing to ramp that up again.