Ping Sensor

Being completely new to the Arduino world, I'm unsure why when I connect my HC-SR04 to my Arduino Uno according to the diagram here: Google Code Archive - Long-term storage for Google Code Project Hosting., my Arduino board loses it's power when connected to my laptop via USB. Do I need to connect an external power source as well? Or am I missing something in the connections? If both the USB power and the 9V are connected will this harm the board?

Thanks for any advice.


Hi, I have used this circuit and had no tproblems, if you unplug the wire that goes from 5V on the arduino to the ping, does the problem still occur.
If the problem disappears then you have a problem on the protoboard.
When you plug a 9V battery into the DC socket the onboard circuitry switches from the USB to a regulator running off the 9V battery.
When you say losses power, what exactly do you mean, the LED on the arduino go out or what.


Thanks Tom. The losing power refers to both the LED and 'On' indicator of my Arduino going out. When I unplug from the 5V then both return. So this may be a problem on the protoboard? I've wired it according to the link provided earlier.

Thanks for your time,

Got it figured out. Embarrassed to say that I had the Vcc and Gnd switched. Works just great now.


Good stuff, John, a Homer Simpson moment, deeerrrrrr.

Have fun mate, Tom..... :slight_smile: