Using edge count to decode an encoder
The rising edge-count measurement is available on some newer scopes. I don’t automatically think of it as, “I’m working with my scope, even though it’s available on my everyday scope and it’s a simple concept.” To set it up, you specify one or two thresholds, and the scope counts the number of times the waveform passes through the threshold(s) in a rising direction. Some instruments also offer a falling edge-count measurement.
In this case, Julian needed to learn more about the pulse output of a rotary encoder. I’ll let him tell the story in his own words:
It turns out this was exactly the count Julian was looking for, and he was able to confirm that the output configuration was as he had expected. Using the edge-count measurement was a quick way to check the output of Julian’s encoder. If you have other ideas for using edge counting on your scope, let me know or post up in the comments section.
Read more in the Scope Guru on Signal Integrity blog.
Dave Pereles has worked in the test-and-measurement industry in various roles, including applications engineering and product management, for more than 25 years. He has a bachelor’s degree in electrical engineering from Trinity College (Hartford, CT) and a master’s degree in business administration from Seattle University (Seattle, WA).