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Calculator screen display

hello guys,

i am sorry again but i hope i can get an answer does anyone know how to work with a small calculator display ?

i have one between my hands i am trying to make it work if it's possible the screen, not the calculator, to make a count from arduino

so is that possble ?

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Meh I wouldn't bother. For LCD stuff it's easier to buy some with decent pins and there are even some (though more expensive) that support protocols like serial. 

Here's an example of a more user-friendly LCD screen:


actully the thing is that i had no screen between my hands so i thought if i can get one from an old calculator that i have but unfortunately it can't work but doesn't matter now i will buy one

LCD displays need an AC signal (50% duty cycle). DC will permanently damage the LCD.

aha so how is the signal converted to AC in a calculator ?

It is not a sine wave like the power from your wall, the digital outputs to the display and the common pin are inverted and then returned to normal. It was a long time ago since I've done this so I can't remember the minimum frequency required but it was not very high.

ok thanks

I remember various old projects that uses the calcuator's screen from the BEAM robotics community, they use solar panels for the power and some 74hc240 to display their name and use it as an electronic name tag.




Its totally unmarked so no one apart from the original designed will know the pinout. Your best off just buying a character display.

ok thanks a lot,

it's just that i don't have a 7 segment right now so i thaught if i can make a display screen but it can't be done so thank u

It probably won't be worth the effort.