Hypnotize said:
I know how to do that, I just need the datasheet of the LCD. If someone could link me to a standard LCD 8 digit display dataheet I should be able to do it. the LCD is not fed with an AC, the battery in the calculator is DC. Maybe the calculator chip inside sends square waves to the LCD but I don't think so.
LCD's like used in calculators are usually custom-made for that particular device, which is why you can get calculators and electronic toys and things like that with custom symbols and things on their displays. Thus searching for a datasheet for a device that is proprietary and not separately commercially available is an exercise in futility.
Not to mention, usually in calculators and similar devices, the connection between the board and LCD is made via a weird stacked conductive rubber strip that is sandwiched between the LCD and conductive pads on the controlling PCB. To make connection to all of those pins, you'll have to either scrape off a lot of solder mask and end up with a heap of very small solder joints just waiting to be ripped off, or go around and solder wires to all the destination pins. Either way it's going to be a big ratsnest of wiring, and probably not work at all if you're not very good at soldering.
And yes, I think we all realize that a battery provides DC voltage and not AC. But LCD's that are directly driven like that ARE driven with AC. Your unfounded belief that that is not the case leads me to believe that you probably aren't aware of how much of a headache this project idea of yours would turn out to be, and it sounds like you really ought to reconsider what you're doing.
Let me put it this way, it would be easier for you to make a calculator from scratch with a microcontroller, using a standard easy-to-use character LCD with an on-board controller, and add this RF thing you want to it, than it would be to do what you're trying to do.