Sometimes finding a short-circuit is easy, especially after the magic smoke has escaped. Finding a short on a newly etched or milled board though, can be a maddening task. Many of us have been there – wrestling with multimeter probes under a magnifier trying to find the offending bit of copper that is the source of all our problems. [Jaromir] designed Shorty to make this task a little bit easier.
Shorty is a short-circuit finder – but it’s not exactly like the one you would find on a typical multimeter. [Jaromir] used MCP6041 Op-Amp to detect resistances down to the order of tens of milliohms. Determining an exact resistance measurement at these levels would require a heck of a lot of calibration. When looking for a short though, [Jaromir] is only concerned with the relative value – is he getting closer to or further away from the short. He determines this by sound. The Op-Amp output is sent to the Pro Trinket’s ADC input. The trinket drives a speaker with lower or higher tones based upon the ADC voltage. Much like the childhood game of “hot and cold”, Shorty will direct you right to your short!
There’s still time to enter the Trinket Everyday Carry Contest. The main contest runs until January 2, but we’re having random drawings every week! Don’t forget to write a project log before the next drawing at 9pm EST on Tuesday, December 30th. You and all of the other entrants have a chance to win a Teensy 3.1 from The Hackaday Store!
Ha! What a conincedence! I just biuld last week also something similar. I also used a pogo Pin as my probe-end! :D
But I used an 555 instead of a CPU. The blinkyness is determined by the resistance. Also: It looks like a spaceship!
Photo:
http://i.imgur.com/wEh3ppq.jpg
Video:
v0.1 https://www.youtube.com/watch?v=Md-csPdkIUw
v0.2 https://www.youtube.com/watch?v=T14_uHHWRoc
To bad I’m a 555 peasant and didnt used a Trinket MCU :D
Not really. I think the 555 is the better option for this.
However, I would get rid of the led and only used the piezzo, driving the frequency by the resistance.
Can you, perhaps, share the design?
I would like the design too. That’s a really cool little tool to have.
I use a Drawdio for that…
That’s a great looking tool. 555 for the win.
It’s really cool to have someone make something like this at home…but Polar Instruments have been doing it for decades….
Wouldn’t a $5 Arduino be more efficient/appropriate than the trinket? Oh wait, these guys have to use the trinket for these comps, don’t they?
Reminds me of the time I used a GenRad Bughound to find a shorted IC on a circuit board.
Fortunately I found a BugHound for $2 at auction. Unfortunately, I havent used it in the 15 years since I bought it.