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7 Segment lcd displayfor 8051 microcontrollers

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Nov 2, 2008
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7 Segment lcd display

Plz can any one provide me 7 segment lcd display schematic for 8051 microcontrollers, and its code in c.
i dont know much abt micrcontroller,and i cant simulate correct schematics whenever i build one.
so plz give me some suggestion how to make schematics by my self in proteus and some good refrences.
Thank You.

7 Segment lcd display


Re: 7 Segment lcd display

7 segment LCD (google result)


I don't know more about 7 segment LCDs.I think the connection may be same as 7segment leds but i am not sure about it.

The image may useful for others to help oister.

Re: 7 Segment lcd display

Unfortunately, LCDs and LEDs need different drive signals. They will work if you put DC between the backplane and segment (=anode and cathode on an LED) but they will fail after a short time because the one electrode will migrate through the liquid and electro-plate the other.

You need to drive them with AC. This isn't as difficult as it first seems, all you do is drive a continuous square wave on to the backplane (0 - 5V for example) and drive the segment from the output of an exclusive OR gate. One input of the XOR connects to the same signal driving the backplane, the other is the on/off control for that segment so you drive it from the micro.

The effect is that the signal across the LCD is AC with the backplane in-phase with the segment or anti-phase with it.


Re: 7 Segment lcd display

i want a schematic figure in proteus and c code to run it,not hardware.....

Re: 7 Segment lcd display

betwixt said:
You need to drive them with AC. This isn't as difficult as it first seems

...provided you're using a static drive LCD. Once you get into the realms of multi-backplane panels, things get *slightly* trickier! If the OP is just looking for a single digit 7-seg, then chances are pretty good that it will be static drive, but multiple digits are almost certainly going to be at least 2 backplanes.

To the OP, is there any reason why you *need* to drive the LCD using your own circuitry? Given the difficulty involved in ensuring you continually supply the LCD with the correct signals both to maintain the required display AND to prevent panel damage, you may find that whatever advantages you think you've got in using a custom drive circuit over an off the shelf driver quickly disappear.

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