control7 blog

PIC12F675 -Funny Police Light- LED project for Beginners (MikroC PRO)

xenon ark — Thu, 05 Apr 2012 16:43:16 +0000

This is a funny project for beginners. The tutorial will show how to control two I/O of PIC12F675. There is no external xtal included in the schematic. We use internal RC. To set internal RC in MikroC PRO IDE goto Project>Edit Project>Oscillator>Internal RC No Clock

here is the schematic:

the MikroC Source codes:

 
void init_ports(void) {
   TRISIO = 0; // set as output
}
 
void main()
{
   init_ports();
   while(1)
   {
    GPIO = (1<<2);
    delay_ms(50);
    GPIO = 0;
    delay_ms(50);
    GPIO = (1<<2);
    delay_ms(50);
    GPIO = 0;
 
    delay_ms(500);
 
    GPIO = (1<<4);
    delay_ms(50);
    GPIO = 0;
    delay_ms(50);
    GPIO = (1<<4);
    delay_ms(50);
    GPIO = 0;
 
    delay_ms(500);
  }
}

PIC tutorial, Easy LCD interfacing with PIC16F877

xenon ark — Sat, 24 Sep 2011 20:35:56 +0000

This is a very easy tutorial to connect a PIC with an LCD. The program is written by mikroC PRO 4.60 Check the LCD library from the library manager before compiling the program.

the program:

// LCD module connections
sbit LCD_RS at RB4_bit;
sbit LCD_EN at RB5_bit;
sbit LCD_D4 at RB0_bit;
sbit LCD_D5 at RB1_bit;
sbit LCD_D6 at RB2_bit;
sbit LCD_D7 at RB3_bit;
 
sbit LCD_RS_Direction at TRISB4_bit;
sbit LCD_EN_Direction at TRISB5_bit;
sbit LCD_D4_Direction at TRISB0_bit;
sbit LCD_D5_Direction at TRISB1_bit;
sbit LCD_D6_Direction at TRISB2_bit;
sbit LCD_D7_Direction at TRISB3_bit;
// End LCD module connections
 
void main(){
 
  Lcd_Init();                        // Initialize LCD
 
  Lcd_Cmd(_LCD_CLEAR);               // Clear display
  Lcd_Cmd(_LCD_CURSOR_OFF);          // Cursor off
 
  Lcd_Out(1,2,"PIC16F877A LCD");     // Write text in first row
  Lcd_Out(2,3,"control7.net");       // Write text in second row
}

The Schematic:

Demo run:

mikroC download

Download mikroC from here.

Serial Character LCD with AVR

xenon ark — Tue, 19 Apr 2011 03:58:15 +0000

There are several character LCD available in market 16×2, 16×4, 20×2 etc. these are very useful and pretty cheap also. This is a small program to demonstrate how interfacing LCD with AVR. I have used Atmega8 to run the program.

This is the schematic:

Pinout chart:

LCD in action:

Source code:

Download source codes. (VAR studio 4 required)

AVR tutorial – Basic I/O Operation. Input signal from push button and drive LED

xenon ark — Wed, 30 Mar 2011 23:40:08 +0000

This small tutorial will show how to read signal from a push button and on/off two led by the input signal. I have used Atmega48 to write and test the program but you can use any AVR which supports AVR GCC.

Before pressing the push button it is like:

After pressing the push button:

Sketch of the schematic:

Here is the program:

#include 
#include 
 
//Method to read pin status
uint8_t GetKeyStatus(uint8_t key)
{
	return (!(PINB & (1<<key)));
}
 
void main()
{
	DDRB = 0b00000111; //set B0, B1 and B2 as output
	while(1)
	{
		if(GetKeyStatus(0)) //reading B0 status
		{
			PORTB = 0b00000010; //set B1 as HIGH
		}
		else
		{
			PORTB = 0b00000100;	//set B2 as HIGH
		}
	}
}

We can read PB0. When the button is not pressed, PB1 is high otherwise PB2 is high.

AVR PWM

xenon ark — Tue, 29 Mar 2011 13:11:38 +0000

This is a program to show a PWM output. Attach an LED with B1 and run the program. I have used Atmega48 while testing.

Here is the Circuit:

This is the program

#include 
#include 
 
main(void)
{
	OCR1AH = 0;
	DDRB |= (1<<PB1); // PortB 1 as output
	TCCR1A = (1<<COM1A1)|(1<<1);  // OC1A to zero, 8-Bit PWM
	TCCR1B = 1; // Start PWM
	while (1) // Start the Unlimited Loop
	{
		int i;
		for (i=0; i<255; i++) //Pulse Increasing Loop
		{
			OCR1AL = i;  //Change lowbyte of OCR1A
			_delay_ms(10); // Delay of each pulse while Increasing 
		}
 
		for (i=255; i>0; i--) //Pulse Decreasing Loop
		{
			OCR1AL = i;
			_delay_ms(10); // Delay of each pulse while Decreasing
		}
	}
}

Single cell (1.5 Volt) LED flasher circuit

xenon ark — Thu, 27 Jan 2011 12:05:56 +0000

LED is the most interesting part of amateur electronics hobbyist. The main barer of LED is, it needs minimum 3 vlots to illuminate. I’ve found many circuits to drive LED by a single cell alkaline or manganese cell.

This is a complete circuit

This is the coil of my first circuit.

I collected copper wire from a relay and use a plastic-coated paper clip as core.

For Experiment: I used a transformers 12-0-12 part as coil and it worked!

This is the first circuit I made

After making the circuit I wanted to check how long it will work. I found it can illuminate more than one day by a single cell!

The Circuit Diagram

Complete Circuit with ferrite core

Circuit

The Coil

The coil is the important part of the circuit. you can use 20-20 turn to any maximum turns. it will works better with ferrite core but you can use any core. At the first time i used a paper clip as core with 70-70 turns and it worked nicely.

More circuit picture

AVR fuse reset (tested)

xenon ark — Sat, 15 Jan 2011 19:16:29 +0000

When I started to learn microcontroller, i have locked few AVR chips. These chips are very expensive here and hard to found. So I started researching why it occurred. I have found two main reasons why microcontrollers are not responding:

1. wrong clock speed selected

2. Lock bit burned (SPIEN)

I have found a solution to reset fuse bits. here is the schematic.

You can reset Atmega8, Atmega48, Atmega88, Atmega128 by it.

Download the hex and burn it to a Atmega8.

IC1 (ATmega8)	IC2 (ATmega8/ATmega48/ATmega88/ATmega168)

PD0	PB0
PD1	PB1
PD2	PB2
PD3	PB3
PD4	PB4
PD5	PB5
PD6	PC0
PD7	PC1

PB1	PD4
PB2	PD3
PB3	PD2
PB4	PD1
PB5	PD5

PC2	PC2
PC3	PB6 (XTAL1)
PC4	PD6
PC5	PD7

PB0	Vcc, AVcc

No external xtal required. In the schematic the two AVRs are connected directly. You can add 1Kohm resistor to every line to provide some protection for the ATmega8 against inserting the target AVR incorrectly.

Download source and hex from here