I'm designing a velocimeter and I'm having doubts about the display's brightness control.
I have an ATTiny 2313 microcontroller connected to a CD4511 that drives a common-cathode 3-digit 7-segment display. On the MCU, 4 GPIO pins set the digit pattern and 3 GPIO pins select the digit through the transistors.
I'd like to have a potentiometer to control the display brightness. My first thought was to connect it to the display cathode, but each number in a same digit will be of different brightness.
Second thought was to connect it to the CD4511 5V pin, but I don't know if it will mess up the internals (the minimum is 3V).
Does anyone know a better way?