help me to power my pic16f877a

[aldawan]

hi am new members and i new in micro controller
i have a pic16f877a and i want to power it
what should i do??
connect its pin 11 and 12 to 5v and ground only or connect pins 32 and 31 too >
thanks

 

[vinodstanur]

Just use all the Vdd and Vss

 

[bigdogguru]

Straight from the horse's mouth:

Many PICmicro MCUs have more than one VSS or VDD pin. This is common on
devices with higher pin counts. These pins are generally connected internally but
through a finite impedance. To insure proper operation, all VSS and VDD pins need
to be properly connected externally.

Microchip Power Considerations

BigDog

 

[aldawan]

thanks for reply . i wanna ask a q?
i have 20*4 lcd and i want to power it
it a 16 pins VSS, VDD,VEE,RS RW , E , and from D0 to D7 data line and oins 15 and 16 should i connect all thi pins or what

 

[Luciferus]

VSS -> GND
VDD -> +5v
VEE -> connected to the middle pin of a 3 pin variable resistor... like this: 1st pin +5V... 2nd pin LCD-VEE... 3rd pin GND
RS, RW, E -> the connection depends on your design, per example, with an Arduino, i connect RS and E to Arduino, and RW to GND
D0 to D7 -> again, it depends on your design, you can use 8bit connection or 4bit connection, 4 bit is the most common and you use less pins
15 Led+ -> you can put a 330 ohm resistor in +5v to switch on the light of your LCD
16 Led- -> GND

 

[aldawan]

hi could you draw to me the right connection in 4 bit to connect pic16f877a to 20*4 lcd

 

[alexan_e]

Here is a basic schematic for the LCD display



The R/W pin is hardwired to GND in the schematic (write only operation) but this depends on the library implementation , you may connect it to the mcu.

Alex

 

[aldawan]

hi could any one draw to me a flow chart for this code

#include <16f877a.h>
#use delay(clock=20M)
#include <lcd420.c>
#include <LCD_D.h>
#fuses hs,nowdt,nocpd,nolvp,noprotect

#byte portc=0x07
#bit led=portc.4

void LCD_D();

unsigned int16 value;

void main()
{
set_tris_c(0x00);
led=1;
delay_ms(500);
LCD_D();
delay_ms(50);

while(1)
{
set_timer1(0);
setup_timer_1(t1_external | T1_DIV_BY_1);

delay_ms(1000); // in protues, should be 1000/3

setup_timer_1(T1_DISABLED);
value=get_timer1();
lcd_gotoxy(11,2);
printf(lcd_putc,"%LU HZ ",value);
led=!led;
}
}