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srspinho
- 29th April 2005, 13:47
Hi firends,

I´m trying to drive an 8-digit LCD (calculator´s like) with a PIC 16F877

I know it iso not very easy, but I must use a display like that.

Have someone ever tried to do that ?

Some tip on how to start doing that ?

Thank you !

Sérgio
mister_e
- 29th April 2005, 14:00
do you have any part# for your LCD or datasheet. That will be helpful in case you really need help by someone here ;)
srspinho
- 29th April 2005, 14:08
Hi Steve,

you´re right about the Part#

The problem is : I have a big box full of those 8 digits calculator´s LCD (aprox 2000 units) with no Id´s, but I know they were origanlly designed for calculators.

I did some comparisons with some other chinese calculators and the display pinout are practically the same, with some no relevant changes (pin spacing etc)

What I would like to know is the main idea on how to drive a regular LCD with no embeded controller and if it is possible to be done with PicBasic.

Thanks

Sérgio
mister_e
- 29th April 2005, 14:27
Regular LCD must have a regular frequency running on the backplane pin. HPWM can be used for that. Once you have a frequency on this pin, just try to find the according pinout.

Basically it's not really different than to drive regular multiplexed 7 segment display

and yes you can handle it under PBP, but it's maybe easier to use LCD driver IC for that depending on your programming skills.
G8RPI
- 3rd May 2005, 11:12
Hi Sergio,
Thave a look at the PIC16F913/4/6/7 series of PIC http://ww1.microchip.com/downloads/en/DeviceDoc/41250C.pdf
These have LCD drivers built in and are supported by PBP. They will connect directly to your 7 segment calculator LCD.
HTH,
Robert G8RPI.
srspinho
- 3rd May 2005, 12:14
Hi Steve and Robert,

thank you for your tips.

I would check the pic 16F913.

It seems to be a good option.

Thanks

bye

Sérgio
EDWARD
- 4th May 2005, 09:47
correct me if i am wrong. a 14 OR 16 PIN LCD WILL WORK WITH THE PicBasic Pro compiler's LCDOUT command. do a search on LCDOUT and connection diargram are around. search this place as well as google. the lcds must have a built in driver, they are really small so you might just see a black blob or tape on the lcd unit. if it meets these requirements then it will be VERY easy to program with minimal wiring, well 10 or so.
NavMicroSystems
- 4th May 2005, 10:27
EDWARD,

Sergio is talking about "Dumb" LCDs with no embedded logic at all!