I purchased a couple 7-segment leds from Mouser and hooked one up to an arduino using a shift register. The decimal point on the LED displays much brighter than the other segments. This occurs with both LEDs that were purchased. Bad leds? Not connected correctly? Normal?
LEDs: http://mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMvkC18yXH9iIgvC7dgeX7B5LAxLP43vLdY%3D
Cell phone video of what's occuring(3g2 will play with VLC/quicktime): http://rapidshare.com/files/262184633/7_segment.3g2.html
Typical, I think. The segments usually consist of several LEDs in series for even illumination (three LEDs for each segment in the display you reference, according to the datasheet), while the decimal point will be a single LED. You need to adjust the current limiting resistors and/or multiplex times accordingly.
That makes perfect sense. I didn't look at the specifications close enough to realize that there's three 2-2.5V LEDs within each segment. Thus, not enough voltage and current to power it brightly. I hooked up a separate 9V battery to the common anode line and it's very bright. Thanks :).