As the display has a very high light output, it gives trouble during night operation. So I like to dim it during dark. Is it possible to vary the display voltage supply e.g. from 5 to 9 volts to establish this? Of course without effecting the time indication. Thanks in advance.
There is a mode which turns off the display but keeps the time.
If this does not suit you, you can put a low value zener (e.g. 2V7) in series with pin 1/5 of the display, to lower the voltage. With a small switch, you could short the zener for daytime use.
Very neat solution, I did that and it is perfect. Instead of having 9V on pin1/5 of the display I’ve got 6.8V which is much better during the night.
The PIC was faulty, I sent it back to Velleman and it was replaced in less than a week.