HC-SR04 Board Mount with LED

Thanks mayaway for creating the original.

Changed a couple of things, adding an LED that's connected to the echo pin (with a current limiter in series). It will pulse the same length of time as the echo pin is pulled high, so short distance pings will produce a very short blip on the LED. Oscilloscope screenshots are of the echo pulse.

The other way to add an LED is to let the microcontroller drive it; that way you're not dependent on the echo time. I only have 4 wires in the cable (use