control a 5 digit - LCD-7-Segment-Display

Hi @ all.

I have an old LCD display, which I would like to use again. see attached picture

A normal 7-segment display is essentially easier, here I need help.

Is there a finished script or a library to control the display?

best regards.

It has nothing to do with scripts or libraries.

Unless you have the display driver chip for that display, forget it!

It s possible to use a MAX7219 driver to custom drive that display but I doubt if the effort would be worth it unless it’s a challenge for you in hacking. Since you know the pin outs it would be possible to drive it with some customizing. This is something you need to figure out if it’s worth it for you.

wolframore: It s possible to use a MAX7219 driver to custom drive that display

Did you see the term "LCD" in the question? :roll_eyes:

Good point Paul... NXP makes LCD drivers.

LCDs are driven with AC, I think maybe around 100Hz, not sure. There is a back plane connection , which I am guessing are the ones marked COM1 etc. There should also be a connection for each segment. You drive them by applying a square wave to the back plane and to a segment. You change the phase of the segment drive to be in phase (segment off) or 180 degrees out phase (segment on). If you don't want to risk damaging this display buy a cheap LCD and experiment with that.

Ah, but it is nowhere near that simple!

There is not a “backplane”, but three multiplexed commons (look at the image link in the first post) which are driven with multiple voltage levels - only slightly simpler than the HD44780 based displays.

You need a driver specified for the particular job.