Newhaven 4x40 LCD, issues!

[Darrel Taylor]

A 4x40 is really two 2x40's.
And it can be handled this way ... http://www.picbasic.co.uk/forum/show...=2388#post2388

[MOUNTAIN747]

Thanks for the link Darrel, I'll check this out. It looks like it will solve my problem.

Thanks again!
Wayne

[Christopher4187]

Talk about timing. I just received two Newhaven OLED 4x20 LCD's in the mail today (http://www.newhavendisplay.com/specs...420DZW-AY5.pdf). A couple of questions:

I am putting this on a Microchip demo board (MCP2515) and I can't use all of Port B. Can I use any 8 pins that are free? Also, what is 4 bit operation and is it worthwhile to use it? The datasheet says that 4 lines aren't used when it's in 4 bit operation so I'm curious of using 4 less pins would be advantageous without losing any clarity on the LCD screen.

Sorry to hi-jack the thread but it seems appropriate in this case.

[mackrackit]

http://www.picbasic.co.uk/forum/show...ght=lcd+anypin

[Christopher4187]

http://www.picbasic.co.uk/forum/show...ght=lcd+anypin

Thanks for the link. Regarding my other question, is there any great benefits to using 8 bit (clarity/speed) or will 4 bit do the job? If 4 bit will do the job, just so I understand correctly, I need 7 pins from the PIC:

1. RS
2. R/W
3. E
4. Low order, bi-directional (1)
5. Low order, bi-directional (2)
6. Low order, bi-directional (3)
7. Low order, bi-directional (4)


Am I on the right track?

[mackrackit]

R/W goes to VSS.

8 bit is a tad faster by the math but I do not think it is humanly noticeable. I never use 8 bit as pins get ...expensive...

[Christopher4187]

Are you sure the R/W pin goes to ground? DT's program and the datasheet both show that R/W gets connected to the PIC. I ask because I'm not getting anything on the screen. DT's programs seems to have complied just fine, although I'm not sure if I did everything correctly.