Hoping for some direction from kind folks

Thread Starter


Joined May 4, 2014
Hello, I just joined this forum today. I am trying to do a part of a proof of concept that seems like it should be simple.

I've seen this channel: https://www.youtube.com/user/startingelectronics and they have a tutorial in the direction I think I need to go, using an arduino board.

My problem is getting started - and that is the direction I need. I'm a decent programmer, and feel pretty confident on that end, its just the electronics part.

What I need to do:

I need to measure the duration of time that a 2.8 volt LED is lit. I don't need to measure anything but that duration 0 - the total time is what I am after, so I can do stuff with that info. I'm a bit apprehensive about frying my computer :).

Can someone help me get started - at least what to buy? I have a multimeter, some leads, a battery, soldering iron, etc. I'm lighting my LED now.

Should I get a breadboard, an arduino board - do I even need one? Any input getting me rolling would be much appreciated.




Joined Aug 21, 2008
The basic circuit is below. The 10k resistor can be replaced with a larger value for more sensitivity.

Connect the collector to the input port of a microcontroller and start measuring.


Joined Nov 7, 2013
What accuracy and time period?

Miliseconds or weeks?

Do you just want a practical solution, or something to learn programming or put in production.


Joined Jan 21, 2013
can you access the leads of the LED you want to measure? Alternatively can you cover the LED?

If you are a programmer then an Arduino (or PIC) may be a good option since most of the effort will be in programming not electronics.