Maker Pro
Maker Pro

Brightness control for HDSP 2133 dot matrix displays

Naveed ishtiaq

Jan 21, 2017
Jan 21, 2017
I need technical help regarding the Brightness control for these displays . I don't want to use internal brightness levels (8 levels) that is its built in feature.

I want to change the brightness levels using 10 KOhm Variable Resistor with PWM (Pulse width Modulation) technique to have a smooth effect of brightness changing levels.

I am not interested in Night Vision circuitry that is recommended circuit of PWM for Night vision applicability by Avago Technologies and is written in Application Note 1039.

I need intensity control for HDSP 2133 Alpha numeric dot matrix displays so that it can change Brightness levels 0% to 100% smoothly with sunlight readability. Earlier I tried with PWM (modified night vision circuit recommend by application note 1039 by avago technology) but couldnot 100% duty cycle.

The attached circuit highlighted in red is the one that I have modified for sunlight readiblity

May be some one can guide me some good techniques to do so.

Your urgent technical solution will highly be appreciated.


  • IMG_20170121_173757_160.jpg
    180.1 KB · Views: 45
Last edited by a moderator: