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Graphic Serial LCD with 68HC11

broker

New member
hello,
i've browsed about 7 pages of this forum making sure not to repeat an already asked/posted question. the closest that i found was:

https://forum.crystalfontz.com/showthread.php?threadid=2795

so here's my question/problem:

i want to interface a 68HC11 chip w/ a graphic LCD driven thru the serial port. i'm using it to build a game controller. here's the specs, it must be:

1. serial driven
2. graphical (capable of handling bitmap and other block chars)
3. built-in controller
4. w/ backlight
5. supports a keypad/push buttons or joystick

the closest model that i found was the 634 serial LCD: http://www.crystalfontz.com/products/634/index.html
but i'm not sure if that's my best bet.

the Graphic LCD line sounds pretty good too but they don't say if it's serial or not. for example:
http://www.crystalfontz.com/products/12864b/index.html#CFAG12864BWGHV

http://www.crystalfontz.com/products/12864a/index.html#CFAX12864AWFH

and

http://www.crystalfontz.com/products/12864c/index.html#CFAX12864CWGHTS

i really like the product and the forum and i'm hoping that i'll get some assistance in helping me choose the right LCD for my project.

thanks and sorry for the long post.
-broker
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CF Tech

Administrator
None of our graphic displays are RS-232 serial.

You can talk to the CFAX* displays using SPI.

The CFA-635 can be had in serial by special order, but it is a character with tiled pixels, not a full graphic.

Why do you want the serial interface? You should just be able to talk to any of our graphic displays (and switches, etc) directly with the HC11.
 

broker

New member
tech,

if none of your LCDs are serial rs-232 then what's with the Serial LCDs? i'm confused ... as a newbie.

also you said: "You should just be able to talk to any of our graphic displays (and switches, etc) directly with the HC11"
how? can you be a little bit specific and maybe recommend a particular model?

thanks
 
CF Tech said:
None of our graphic displays are RS-232 serial.
The serial RS232 displays are character mode.

The CFAX series graphic displays have a serial capability (but not RS232), you can use an I/O port to control them. What screen size/resolution are you looking for? You will have to handle the keys separately from the display, on another I/O port.

Afterthought: the serial mode on the graphic displays is for entering the data bytes (2 I/O bits - clock & data, instead of using 8 bits in parallel), but you will still need to use other I/O pins for the control signals.
 
Last edited:
There would not be much difficulty in connecting the CFAG12864 to a HC11. You would need 1+1/2 I/O ports. One port for the data bus, and another 4 or 5 pins for the control signals. Do you have enough unused pins to do this?

The other consideration is the software. For the HC11, I'd presume you're writing in assembler. It would take only slightly more code than if you were using the serial port, and probably much faster than serial. I've got some HC12 code you could use as an example.
 

broker

New member
cosmicvoid,
thanks very much. i got the code. the specs of my project got changed a lil' bit and i've been trying to made adjustments to the prev design.

i haven't gotten the programming part yet but when i do i'm sure you'll here from me.

thanks
broker
 
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