Problem with LCD that is controlled by PIC16F877

[meera83]

i m using PIC16F877 to run LED and LCD Display, the LCD that i use is type CMC216x01..(www.cct.com.my)
after i burn my program code inside PIC and run it..
the LED can blink as i want, but the LCD show nothing...

before that,the PIC that i program can run well on PICDEM2 PLUS(the LED and LCD can show the result)..
i just move the PIC to the board that i built but it only can show the LED result but not LCD result..

the LCD pin i just connect to PIC directly using wire:
pin1(Vss)=Gnd
pin2(Vdd)=+5V
pin3(Vo)=potentiometer
pin4(RS)=RA3
pin5(R/W)=RA2
pin6(E)=RA1
pin11(DB4)=RD0
pin12(DB5)=RD1
pin13(DB6)=RD2
pin14(DB7)=RA3

 

[supersonic_ab]

problem with LCD

I am not equipped with the knowledge of PIC but I worked on AVR with LCD and what I can figure out is that the potentiometer is not properly set.

Does it get initialized?
If yes, then it might be some other prob but if it doesn't then the prob may be the same as given above.

 

[meera83]

Re: problem with LCD

I am not equipped with the knowledge of PIC but I worked on AVR with LCD and what I can figure out is that the potentiometer is not properly set.

Does it get initialized?
If yes, then it might be some other prob but if it doesn't then the prob may be the same as given above.

what you mean by 'get initialized'??
for the potentiometer, i had adjust from the maximum to minimum, but the LCD still show nothing..
before that, i had try to test the LCD by stand-alone circuit(with no microcontroller) which connect the LCD pin to resistor and +5V..the LCD still able to show a row of black box..

but with the PIC and source code, the LCD show nothing..

i have no idea with where i can troubleshoot with my problem??

 

[Prabakaran]

problem with LCD

Dear Meera ,
may be the configuration problem with ur code about the initialization of LCd.
Configure ur software for RS and R/W , Check ur command mode for sending the commnads to LCD. if u still face the problem i will send the code to u.

 

[Kurenai_ryu]

problem with LCD

some lcd need that Vo should be intitalized before sending data/commands, it's no use to change from "min to max" after the initialization commands have been send (I suppose at the begining of your program...), maybe you can put Vo to GND (it works for many lcd...) and how about the black row??? does it shows when you connect the PIC??? if it`s not well initialized it should be there...
try it...

 

[supersonic_ab]

Re: problem with LCD

I am not equipped with the knowledge of PIC but I worked on AVR with LCD and what I can figure out is that the potentiometer is not properly set.

Does it get initialized?
If yes, then it might be some other prob but if it doesn't then the prob may be the same as given above.

what you mean by 'get initialized'??
for the potentiometer, i had adjust from the maximum to minimum, but the LCD still show nothing..
before that, i had try to test the LCD by stand-alone circuit(with no microcontroller) which connect the LCD pin to resistor and +5V..the LCD still able to show a row of black box..

but with the PIC and source code, the LCD show nothing..

i have no idea with where i can troubleshoot with my problem??

hey listen
what value resistor you are using??
In a potentiometer used the ratio of division of the resistances is very high.

GND--------------LCDpin---------------Vcc
0.03M 125M(b/w PIN and Vcc)
This is what my multimeter shows the resis to be. Use the ratio of resis. as above if possible.(0.03:125).Use this in your dry run. By 'getting initialized' I mean that that if initial commands are sent to it properly. Does the LCD cursor blinks??

 

[meera83]

problem with LCD

thanks to all of your reply..
i will try to trobleshoot it with the advise that you guy suggest..

thanks..

 

[dnhuruag]

Re: problem with LCD

hey try Vo connected to ground... since most of these lcd need not to set it's contrast with a potentiometer... if something goes wrong then it's probably your program isn't working at all...