LCD setup

[nomad]

you show RS on pin ra4 but define says rsbit 3. also typically ra4 is open collector or open drain as an output and will need a pullup resistor. which pic are you using?

[nomad]

hey no fair you changed it while i was posting. lol. ok so that leaves the pullup issue.

[ruijc]

hehehe...

sorry nomad,

right now i'm slow thinking, but i got there

i'm using a 16F628.
Also have a pullup 100K resistor...but still not working...

.

[nomad]

100k might be to large. too weak a pullup. i usually see 10k or even 4.7k as the pullup. check your input/output trisA settings and disable comparators, cmcon=7? ra4 is tied to cmp2.

[nomad]

oh yeah, also make sure the R/W line isn't left floating. needs to be grounded i believe. did you set 4 bit mode? DEFINE LCD_BITS 4. thats all i can think of without having the data sheet here or seeing the code. hope that helps.

[ruijc]

Hi nomad,

i think i know what's going on !

the thing is that i moved the stardard configuration to give me the RA0 and RA1 free and use them for analog input.

I have my code set for all PORTa to be input and analog...dahhh ( therefore the lcd RS to pic RA4 is not working )

TRISA = %11111111 ' Set PORTA to all input
ADCON1 = %10000010 ' Set PORTA analog and right justify result

This is why it doesnt work.

I need to set ONLY PORTA 0 and 1 ports analog and not all.

I will remove the first line ( trisa = %1111111 ) because it doesnt make any sense.

About the second line : ADCON = %10000010...

how can i set only RA0 and RA1 analog and the rest of the portA digital ?

thanks

[nomad]

You need the TRISA line. each bit determines input or output. so if you want ra4 as an output you need to change trisa to %11101111 also need cmcon=7 to disable the comparators. I dont have a data sheet to see what you need for adcon1 but the analog is for input only, and doesn't apply to a pin set to output. (as far as i understand) i think the cmcon and trisa lines should do the trick.