Make sure download the library for Arduino DUE board before you upload the code. It can be done by click the board manager and download the SAM3x board. This code can count pulse which last at least ...

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 something [FrankBuss] has approached with an Arduino-based counter that offloads the timing question to a host PC, and thus claims atomic accuracy due to its clock being tied to a master ...

The duders over at cookinghacks put together an Arduino based geiger counter. It's set up to click a speaker at every pulse for an immediate indication of radioactivity.

When the counter is reset, the pin gets set low (or high) – setting the output pulse width. The problem I am most confident in understanding is the long first pulse. TCNT1 is the actual counter ...

Raspberry Pi programmable timer “To make things more interesting, you can modify the provided source code, and re-program the Ninja Counter itself using an external Arduino Uno!