What components to make LED bar graph up/down counter?

[Stoph]

Hey all,

Wanting to create an up/down counter that uses a photogate as a trigger, and a 12 segment LED bar graph to display the count. It will need to begin at full illumination, turning off one at a time on activation of the photogate. Will also need a reset switch, though I'm thinking a simple break in the circuit to turn off when disengaged, reverting to full illumination when power restored would do?

Wondering if I can retrofit a standalone up/down counter kit, or whether I'd need to go as far as to invsst in an arduino board and learn code? if there's a route that achieves what I need that avoids going to that extent, id prefer that.

Size and power both small if possible.

I've done some reading, but without a firm point of reference on which to draw a bearing, I fear I'm going in circles and not getting anywhere.

Any help much appreciated!

 

[meBigGuy]

You could use a shift register to build such a "thermometer" code display. Here is a good page on shift registers.

http://www.allaboutcircuits.com/vol_4/chpt_12/4.html

Even if you used an arduino, such a circuit saves IO pins (which is sometimes important).

My bias is generally to use a processor since you can easily tweak your code to modify behavior, deal with startup and reset conditions, change sensitivity rules, etc. Learning to use arduino is move into the future.

 

[Stoph]

Thanks for pointing me in the rght direction, MBG!