GLCD idea

[championx]

Hi everyone! i am starting to develop a circuit that will use a GLCD. Its my first GLCD experience.

I was just thinking, is it possible to use a 74HC595 shift register to manage the data lines? this is just to gain some pins and use them in other periferals.

Thanks!

[temtronic]

Yes, possible but......

some 'issues'...
1) you'll have to make your own driver( well, modify an existing one).
depending on your level of experience this can be easy or almost impossible.

2) speed or timing issues.data to the GLCD will be slower, maybe 1/8th 'regular' parallel I/O mode.Something to consider,though with a fast PIC you'll probably not notice it.

3) overall speed of the program will be slower since the PIC has to take the data and send to the 595.

4) PCB layout,cost,etc. to add the 595. Might be cheaper to just buy a bigger PIC.I like using the 18F46K22, kind of a 'swiss army knife' PIC. I use the 40 pin version, have yet to run out of I/O!

5) time to implement the product.You could run into problems creating the 'predriver' code(what goes between data and the GLCD regular driver).Depending on what your time is worth,again cheaper to use a bigger PIC.

others will come up with pros and cons....

hth
jay

[championx]

Thanks for your reply temtronic!

Writing the driver is not an issue, i use this ic a lot. Ill give it a try.

Im currently using a 18F46K80 (40 pin version), but im running out of IO pins... it has a lot of periferals.

Ill give it a try and post any comments on it!

thanks!