So [Todd] has set out to build an Arduino frequency counter for a Kenwood TS-520S HF ham radio. This post (and the video found after the break) doesn’t cover the entire project. It’s rather ...

If they use an Arduino, it should have been an ATtiny. And of course, if an ATtiny was used, there should have simply been a 555 timer ... CD4017 which is a decade counter/divider used for ...