I have been creating home projects for the last 40 years and have actually done quite well in a number of worldwide design contests. Here are links to an award winning project for monitoring a sump pump and a battery charger monitor project.


I'm still using the sump pump monitor 24-7 although I would like to update the "Ethernet Unit" to use more of an IoT approach to logging data instead of syslog.

But the new Keysight test gear got me thinking about my speaker phase tester based on the 1st generation National Semiconductor COP8 FLASH Microcontroller. It won 3rd place in the COP8 FLASH design contest about 20 years ago. This project produces a test signal that drives a loudspeaker and uses a microphone placed in front of the speaker to detect whether or not the speaker is in-phase or out of phase (in-phase meaning the cone pushes out when the plus terminal is more positive than the minus terminal on the speaker). Under these conditions a bi-color LED illuminates green and if the wires to the speaker are reversed (or you are able to place the microphone behind the speaker when it is functioning correctly) it illuminates RED as seen in the picture of the project.

I would like to design a new version of this project based on a newer processor with the goal of having an adjustable phase window so it could be used on speaker enclosures with crossovers and multiple speakers. However, I do not have access to a capable signal generator for some of the R&D involved to determine the optimum stimulus waveform(s) for this, not mention a decent scope, as the pictures bears out. (This is where Keysight comes in...catch my drift?)

I'm sure the Keysight test gear would also help me bring other projects to fruition as well, but I suffer from the same condition as the now famous Mark Hughes suffers from. If you don't know who he is search for him in the list of entries. You won't be sorry you did.


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