No, I'm not connected with AdaFruit.... but I like them very much.
https://www.adafruit.com/
https://learn.adafruit.com/adafruit-neopixel-uberguide/overview
The software brightness control added to the strandtest demo works like this:
// Connect a potentiometer between the Arduino +5v and Ground,
// wiper to Analog Input potPin declared below.
//
// At the top of the sketch before setup put:
#define potPin A0
int MaxBright = 127; //sets initial brightness to half
// then in each display function in the strandtest sketch,
// before each strip.show() statement, put:
MaxBright = map (analogRead(potPin), 0,1023,0,255);
strip.setBrightness(MaxBright);
// and now the potentiometer will control the strip brightness.
