PIC DiscussionBy: Eng. Tamar Jomaa

MicroC programming

MicroC Programming

Outlines of part A:

1) MicroC Basics

2) Simple Examples

3) Lab#8:Introduction to MicroC programming

1) MicroC Basics

It is easy to write your code in C Language, but MikroC

Language is slower than the Assembly language because it

needs two steps to be transformed to machine language.

1) MicroC Basics

How to write MicroC code

1) MicroC Basics

How to make infinite loop in MicroC :

1) MicroC Basics

To clear TMR0 interrupt flag bin?

INTCON.T0IF=0;

To make a delay of 2 seconds?

DELAY_MS(2000)

Set RB5 if RA2 is set?

IF(PORTA.F2==1) PORTB.F5=1;

Int k = 200; delay_ms(K); Not correct

const int k = 200; delay_ms(K); correct

Int k = 200; Vdelay_ms(K);

portb=0x03^0x02; 0011 (XOR) 0010 =0001

Notes:

1) MicroC Basics

In MikroC language you don't need to be in bank0, or in bank1, you

can deal directly with Special Function Registers (SFR).

To make inverting use ~.

To access an individual bit, use the following:

//If RB0 is set ,set RA0

if(portb.f0==1) porta.f0=1;

Notes:

1) MicroC Basics

OPERATORS :

1) MicroC Basics

Relational operators:

1) MicroC Basics

Bitwise operators:

1) MicroC Basics

Logical operators:

1) MicroC Basics

Selection statements:

There are two types of selection statements in C:

1. if

2. Switch

1) MicroC Basics

1) MicroC Basics

Do statement

1) MicroC Basics

Functions:

1) MicroC Basics

function Example:

1) MicroC Basics

Open -Drain RA4 on PIC16F84A

1) MicroC Basics

Open -Drain RA4 on PIC16F84A

1) MicroC Basics

Open -Drain RA4 on PIC16F84ASome PICs like PIC16F84A have RA4 with open drain output instead of CMOS output!

RA4 is different; it is configured as an open drain MOSFET. When set to low, it

performs identically with the other pin architectures.

However, when set to high, there is no internal connection with VDD and hence it will not

directly source voltage.

If it’s necessary to use RA4 as a sourcing output pin, you can add an external “pull-up”

resistor, typically in the range of 470 ohms–4.7K ohms.

The sourced current then comes from the pull-up resistor. Unlike all other pins that cannot

exceed VDD, RA4’s open drain is rated to 12 volts.

1) MicroC Basics

Open -Drain RA4 on PIC16F84A

RA4 pin (pin 3 for PIC16F84a) is "Open-Drain" type output pin.

That means it cannot source current and it will be high impedance

when assigned logic '1' to it.

You cannot set this pin as an output pin by using 'TRISA=0x00'.

The solution is attaching a pull up resistor (10K) to the RA4 pin in

order to use this pin as an output pin.

1) MicroC Basics

Open -Drain RA4 on PIC16F84A

1) MicroC Basics

Data Types:

RangeSize in bytesType

1) MicroC Basics

Data Types:

You can defined the variables in three ways:

1) MicroC Basics

constants:

Example: const float pi=3.14;

The constants stored in ROM.

The value of the constant can’t change if for example say pi++.

General formula:

const constant type constant name= constant value

1) MicroC Basics

Matrices :

Index#0

Index#1

Index#2

1) MicroC Basics

Multi Dimension Matrices :

1) MicroC Basics

Multi Dimension Matrices :Example:

1) MicroC Basics

#define:

1) MicroC Basics

Button “ Bounce”:

Counter from 0 to 0x0F, increases by one every press on RA4.

1) MicroC Basics

Button “ Bounce”:

1) MicroC Basics

Button “ Bounce”:

Solution of bounce by using a

small delay

2) Simple Examples

Example#1:Write a code in MicroC to make a LED B0 ON.

2) Simple Examples

Example#1 sol:.

2) Simple Examples

Example#2:Write a code in MicroC to make LED’s in B0,B1,B5 and

B7 ON.

2) Simple Examples

Example#2 sol:

Note:

Trisb=0 ≡ trisb=0b00000000

Portb=0b10100011 ≡ portb=0XA3

2) Simple Examples

Example#3 :Make flasher in all pin’s in portB.

2) Simple Examples

Example#3 sol :

or

2) Simple Examples

Example#4 :Make a party LED’s…

The first shape make led B0 ON then

the next and so on..

The second shape make the LED’s

begin to light ON from the middle.

The third shape make all LED’s ON

then OFF.

And so on..

2) Simple Examples

Example#4 sol :

2) Simple Examples

Example#5 :Make all LED’s in PORTB ON and then OFF. Repeat this process 18.

2) Simple Examples

Example#5 sol :

2) Simple Examples

Example#6 :

Make a LED in B0 ON

when you press to switch

in A0, unless that the LED

is OFF.

2) Simple Examples

Example#6 sol:There are two methods to connect the switches:

Pull-up resistor Pull-down resistor

If(porta.f0==0)

{

Here we write the code when the switch is

press.

}

If(porta.f0==1)

{

Here we write the code when the switch is

press.

}

2) Simple Examples

Example#6 sol:

or

2) Simple Examples

Example#7 :Write a code to make program

consists of 2 switches and 3

LED’s.

When you press to switch#1 the

LED begin to turn ON from LED1

then LED2 and finally LED3.

When you press to switch#2 the

LED begin to turn OFF from LED3

then LED2 and finally LED1.

2) Simple Examples

Example#7 sol:

or

2) Simple Examples

Example#8:You have one switch and 4 LED’s.

If you press the switch the first

time all LED’s become ON.

If you press the switch the second

time, the LED’s begin to light from

right to left.

If you press the switch the third

time, the LED’s begin to light from

left to right.

2) Simple Examples

Example#8 sol :

2) Simple Examples

Example#9 :

You have switch in A0 and

LED in B0.

When you press to switch

the LED will light, but when

you press the switch there

is nothing unless you

released your finger from

switch.

2) Simple Examples

Example#9 sol:

2) Simple Examples

Example#10:Make a binary counter that counts from 0255 in portB.

2) Simple Examples

Example#10 sol:

2) Simple Examples

Example#11:Make a binary counter that counts from 09 and then repeat the

count .

2) Simple Examples

Example#11 sol:

2) Simple Examples

Example#12:Make a multiplication table of 3 in binary, and display the result in portB.

2) Simple Examples

Example#12 sol:

2) Simple Examples

Example#13:Write code to count from 90 by using 7 segment.

2) Simple Examples

Example#13 sol:

or

2) Simple Examples

Example#14:Make a counter by using 7-

segment .

When you press to switch#1 the

counter will increment, but when

you press to switch#2 the counter

will decrement.

2) Simple Examples

Example#14 sol:

2) Simple Examples

Example#14:You have a switch. At every press to switch make the LED light as

the following shape:

2) Simple Examples

Example#14 sol:

2) Simple Examples

Example#15:Write a code when you press to switch in A1 you run the

buzzer, and increase the counter in portB.

2) Simple Examples

Example#15 sol:

2) Simple Examples

Example#16:Make sound tones and display the result to speaker.

2) Simple Examples

Example#16 sol:

Learn:

Sound library consist of:

Sound_Init

Example: Sound_Init(&PORTC,3);

Sound_Play

Example: Sound_Play(1000,200)

where 1000 is the frequency in Hz and 200 is the time in msec

2) Simple Examples

Example#16 sol:

2) Simple Examples

Example#17:Write a C code program to make a flashing wave on PORT B, and

then control the direction, and the speed of the flashing wave,

through PORT A.

2) Simple Examples

Example#17 sol:

2) Simple Examples

note:

PIC16F877A:It consists from 40 pin’s, we

can use 33 pin’s as input or

output.

You can connect source#1

only, or source#2 only, or to

connect 32 with Vcc and 12 with

ground, or 31 with ground and

11 with Vcc.

You must begin your program

with adcon1=0x06; or

adcon1=0x07; in case you don’t

use analog equipments, to use

port A and port E normally.

Rest:

PIC

16F877A

+5V

Port A

Port E

Source#1

Crystal

4Mhz

Port C

Port D Port D

Port C

Port D

Source#2

Port B

Lab #8Introduction to MikroC Language

Design traffic lights to the intersection consists of four directions.(10 marks)

Do this project software

and hardware.

Attach the CD for the

MicroC code and

simulation and send to me

hard copy report.

Only 3 students in every

group.

Deadline: after 5 days

from discussion the lab.

Lab #8Introduction to MikroC Language

Hints:

we want to consider the first road is green and the other roads are red for 2

minutes.

After that turn off the green signal, and still the red signal as previous step.

Turn on the yellow signal for 5 sec in first road, then turn of the yellow signal.

Make the same process for the second road and so on.

Lab #8Introduction to MikroC Language

Do the best you can, you are Muslim.

Be free to ask any questionEng. Tamar Jomaa