help my lcd project lmb16abd and 16f877a

hesho90 · May 1, 2013

hello
i have lmb162abc lcd and pic 16f877a
and this is my code

sbit LCD_RS at RB0_bit;
sbit LCD_EN at RB1_bit;
sbit LCD_D4 at RB4_bit;
sbit LCD_D5 at RB5_bit;
sbit LCD_D6 at RB6_bit;
sbit LCD_D7 at RB7_bit;

sbit LCD_RS_Direction at TRISB0_bit;
sbit LCD_EN_Direction at TRISB1_bit;
sbit LCD_D4_Direction at TRISB4_bit;
sbit LCD_D5_Direction at TRISB5_bit;
sbit LCD_D6_Direction at TRISB6_bit;
sbit LCD_D7_Direction at TRISB7_bit;

void main() {

LCD_init();
Lcd_Out(1, 1, "hello");

}

this i but the code on the pic and use my breadboard to see it but nothing is there

5v reg

hesho90 · May 1, 2013

ligo.george said:
Did the Proteus simulation work?

Try after connecting D0, D1, D2, D3 to ground... adjust the contrast of the LCD by varying the pot..or preset.

i wired all the d1-4 to ground

this is my new code

sbit LCD_RS at RB0_bit;
sbit LCD_EN at RB1_bit;
sbit LCD_D4 at RB4_bit;
sbit LCD_D5 at RB5_bit;
sbit LCD_D6 at RB6_bit;
sbit LCD_D7 at RB7_bit;

sbit LCD_RS_Direction at TRISB0_bit;
sbit LCD_EN_Direction at TRISB1_bit;
sbit LCD_D4_Direction at TRISB4_bit;
sbit LCD_D5_Direction at TRISB5_bit;
sbit LCD_D6_Direction at TRISB6_bit;
sbit LCD_D7_Direction at TRISB7_bit;

void main() {

TRISB = 0;
LCD_init();
Lcd_Out(1, 1, "hello");
}

and still nothing and the regulator very hot very fast
and i need help to know my ground from vdd in the pot

hesho90 · May 1, 2013

ligo.george said:
What is the value of POT you used?
Check whether the VDD, VSS of PIC and LCD are correct ...
Connect the constant resistance points of POT to VDD and VSS, variable resistance point to Ve of LCD..
Check the link that I give you...

do i have to use the same code from the your link

jayanth.devarayanadurga · May 1, 2013

Post your LCD connection circuit.

hesho90 · May 1, 2013

some black dots are shown on the lcd

d7-rb7.d6-rb6.d5-rb5.d4-rb4.en-rb0.rs-rb1
vss-gnd-pot .vdd-pot-5v.rw-gnd.d1:4 nothing
v0-pot middle pin
lmb16 lmb16abd

hesho90 · May 1, 2013

this 10k pot

- - - Updated - - -

i did Check

hesho90 · May 1, 2013

do my code need any changes for real circlet on breadboard

jayanth.devarayanadurga · May 1, 2013

Change

Code C - [expand]
1
2
sbit LCD_RS at RB0_bit;
sbit LCD_EN at RB1_bit;

to

Code C - [expand]
1
2
sbit LCD_RS at RB1_bit;
sbit LCD_EN at RB0_bit;

hesho90 · May 1, 2013

jayanth.devarayanadurga said:

this my new code

sbit LCD_RS at RC0_bit;
sbit LCD_RW at RC1_bit;
sbit LCD_EN at RC2_bit;
sbit LCD_D0 at RB0_bit;
sbit LCD_D1 at RB1_bit;
sbit LCD_D2 at RB2_bit;
sbit LCD_D3 at RB3_bit;
sbit LCD_D4 at RB4_bit;
sbit LCD_D5 at RB5_bit;
sbit LCD_D6 at RB6_bit;
sbit LCD_D7 at RB7_bit;

sbit LCD_RS_Direction at TRISC0_bit;
sbit LCD_RW_Direction at TRISC1_bit;
sbit LCD_EN_Direction at TRISC2_bit;
sbit LCD_D0_Direction at TRISB0_bit;
sbit LCD_D1_Direction at TRISB1_bit;
sbit LCD_D2_Direction at TRISB2_bit;
sbit LCD_D3_Direction at TRISB3_bit;
sbit LCD_D4_Direction at TRISB4_bit;
sbit LCD_D5_Direction at TRISB5_bit;
sbit LCD_D6_Direction at TRISB6_bit;
sbit LCD_D7_Direction at TRISB7_bit;

void main() {
TRISC = 0;
TRISB = 0;
LCD_init();
Lcd_Out(1, 1, "hello");
}

jayanth.devarayanadurga · May 1, 2013

Why are you using 8 bit LCD settings for 4 bit LCD? Just use the earlier code and change the two lines I mentioned. If you use 8-bit then your should use LCD8 library.

hesho90 · May 1, 2013

it opens black Square then fide out

jayanth.devarayanadurga · May 1, 2013

fide? fade? Post your new code. Post your Circuit.

hesho90 · May 1, 2013

jayanth.devarayanadurga said:
fide? fade? Post your new code. Post your Circuit.

sbit LCD_EN at RB0_bit;
sbit LCD_RS at RB1_bit;
sbit LCD_D4 at RB4_bit;
sbit LCD_D5 at RB5_bit;
sbit LCD_D6 at RB6_bit;
sbit LCD_D7 at RB7_bit;

sbit LCD_EN_Direction at TRISB0_bit;
sbit LCD_RS_Direction at TRISB1_bit;
sbit LCD_D4_Direction at TRISB4_bit;
sbit LCD_D5_Direction at TRISB5_bit;
sbit LCD_D6_Direction at TRISB6_bit;
sbit LCD_D7_Direction at TRISB7_bit;

void main() {
TRISA = 0;
TRISB = 0;
LCD_init();
Lcd_Out(1, 1, "hello");
}

4mhz crystal and 10k pot and 5v regulator

mohamed.hagag · May 2, 2013

hi
man u didn't have to use regulator or crystal to generate pulses , iam this is the code but by micro c View attachment code.rar

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betwixt · May 2, 2013

The unused (D0-D3) pins of the LCD should be tied HIGH or left disconnected for 4-bit operation, not tied low as suggested earlier. I suspect the real problem here is the layout and lack of decoupling capacitors are causing the clock to act erraticly and the voltage regulator to oscillate. Connect a 10uF capacitor across the input pin and ground pin of the regulator and a 100nF caocaitor between the output pin and ground pin. Also connect another 100nF capacitor between the VSS and VDD pins of the PIC, as close to the pins as possible.

Brian.

jayanth.devarayanadurga · May 2, 2013

Your code is ok. The problem is in your hardware. Maybe regulator is internally shorted.

hesho90 · May 2, 2013

i don't know how to wire them all at the same time when i give power to the lcd it cut off on the pic and the pic cut it off on everything

jayanth.devarayanadurga · May 2, 2013

Google about making breadboard connections. May be you have shorted some connection in the breadboard and that is why regulator is heating up.

hesho90 · May 2, 2013

ones i wire the vdd and the vss of the pic all other power go off

jayanth.devarayanadurga · May 2, 2013

Then PIC is shorted internally.

Code C - [expand]
1 2	sbit LCD_RS at RB0_bit; sbit LCD_EN at RB1_bit;

Code C - [expand]
1 2	sbit LCD_RS at RB1_bit; sbit LCD_EN at RB0_bit;

help my lcd project lmb16abd and 16f877a

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