Help with a tiny LCD

Other Hardware Displays
1

Hi all.

Anyone able to help with this weird little LCD I have here?

The only information I have is this page:

https://leap.tardate.com/electronics101/displays/lcd3digit/

I understand the concept, and I have it breadboarded on a 3v regulator and all ready to go.

But... the demo code he has written is baffling to me.

The screen needs AC to drive it. The 4x common lines need to be swung between rails to provide this AC effect.

I don't quite understand how there is 3 states on a digital pin.
Yes you have 0 and 1, what is (what they call) Z state?
Is that where they are switching the pin to an input which makes the pin float mid value due to the resistor arrangement? I assume so.

Rather than blindly copy this code, I need to understand the concept. I plan to move this over to a PIC16F1823 later on and will only be using simple digital pin commands.

The text says the example is simple Digital commands.... but it isn't really (not for me!)

lcd_module
lcd_module981×1009 272 KB

2

1 and 0 are the conditions of a pin when output. (Or HIGH and LOW).
Z state in digital logic is the high impedance state, commonly when a digital pin is an input.

PS:

Due to the need to control several LCD pins at the same time, the author used a direct pin management technique (PortManipulation), and not the use of better-known instructions such as:
digitalRead() and digitalWrite().

ref:https://docs.arduino.cc/retired/hacking/software/PortManipulation/