cant get my Lcd to work using Pic18f452

[civicgundam]

i could not access the inc file due to access is denied due to school computer. So i tried config 4l by the use of config4l= 0x81

; Default settings
; ================
KB_ROW = 4 ; 4 ROW keypad
KB_ROW_PORT = PORTC ; Keypad ROW on PORTC
KB_ROW_BIT = 0 ; ROW0 = PORTB.0
KB_COL = 4 ; 4 COL keypad
KB_COL_PORT = PORTC ; Keypad Col on PORTC
KB_COL_BIT = 4 ; COL0 = PORTB.4
DebounceDelay = d'200' ; debounce delay 200mSec
CONFIG4L =0x81

[Snap]

I had the same problem and it drove me crazy untill I turned the lcd off an noticed for a spit second my message appear. Really look at that contrast pin and make sure you can fade the boxes on and off. This might not be the solution but it was in my case.
Snap

[civicgundam]

im still trying to get the lcd to work.. i dont know how to configure the lpv to disable and i looked at the contrast and it was fine since i used someones else program using the same pic that im using which is the pic18f452 and it came out working just fine. Im up for anymore ideas or anwsers to solve the problem at hand

[mackrackit]

Read this, http://www.picbasic.co.uk/forum/showthread.php?t=543 it tells how to set the config fuses from inside the program. As mister_e points out in post #5 of that thread, you could still have problems. If you do it will be time to talk to your instructor.

Now about the contrast pin. You said that you are using the same PIC as someone else. Do you mean PIC or project board?

What happens when you adjust the pot tied to the LCD's contrast pin?

It could be either one, LVP or contrast. If it is the same program as your friend , was your friend using the school's system.

Let us know.

[mister_e]

Could be interesting to have your whole schematic.

[civicgundam]

there is no pot on the board that i got. The lcd and keypad was preassembled by my instructor. trying to get a picture and or the schematic but dont have that at the momentThe pic he used was his daughters and it was the same as mine Pic18f452 and was demostrated that it work on the board that i have trouble with.

I would like to take the time and say thank you for helping. Its some of the most help i got so far with this.

so thank you

[mackrackit]

I have ran across LCD that does not need an adjusting pot, the contrast pin could be connected directly to 0 volt (ground) and would work. So it is possible your instructor was using one. But not very possible! I would say this happens maybe 1 out of 100 times. You need the adjusting POT.

Questions that I am still not clear on:

1- Are you using the exact same board and LCD as your instructor?

2- Is the board and LCD a copy of the one your instructor has?

3- Did you instructor compile his/her program on the same computer you are using? ( this is to test the LVP config)

4- What does you instructor say about the problem?

Please provide a drawing showing how the LCD is connected (draw it on paper and scan it if you have to)

Go here http://www.microengineeringlabs.com/support/index.htm and you and the instructor look at the manual under LCDOUT, it shows the correct way to wire a LCD using PORTA as a default. I am not saying to use PORTA, but look at how the contrast is set up.