Embedded programming

This week assignment is to read the attiny data sheet and programming my board to make anything that show that I have learned the programming.

First reading the micro-controller data sheet.

For making this I have decided to use Attiny micro-controller.
Attiny is produced by Atmel company and have many advantages like
- Small size
- Fast and code efficient
- High integration
- 0.7 v operations.

This is the official page of Atmel for data sheet of attiny data sheet
First I have learned is the pin out of the Attiny, which have 14 pins.
This image show the the pin out of the micro-controller

So the micro-controller have one pin for the voltage VCC and one pin for ground GND so I can connect external power to it if I want to use it separately without using usb port of the computer, it also have 8 pins related to data register A DDRA and 4 pins related to data register B DDRB, PB3 can be used as the pin for reset.

One of the advantages of the Attiny is that it contain pull up resistor that I can use it.

For using a port I should write in the code the name of the register I will use then I activate the port then choose it as out put or input.

For example this is the code syntax to put PA5 as output

DDRA |= (1 << PA5);

  // set pa5 as output in DDRA

This code is to show how to put PB2 as input and activate the pull up resistor related to it.

``` DDRB &= ~(1 << PB2); // set PB2 as input in DDRB

PORTB = 0b00000100; // SET PULL UP RESISTOR IN PB3 ```

This a part of the code I will use in this assignment.

Now I have learned the first part in micro-controller which is how to choose the port and use it as input or output.

The second thing I learned was how to use the clock.
By learning the principles of how to use the clock I will activate something called sleep mode so I can make a power consumption of the micro-controller.
This image show the clock distribution in the micro-controller.

There are two types of clock internal clock and external clock.
what I will use is the external clock as I will put oscillator on all boards I will use as the intranal clock have an oscillator of 8 mhz and I decide to use 20 mhz.

The ATtiny24/44/84 system clock can be divided by setting the “CLKPR – Clock Prescale Regis- ter” . This feature can be used to decrease power consumption when the requirement for processing power is low.

This is the code of activation.
CLKPR = (1 << CLKPCE); CLKPR = (0 << CLKPS3) | (0 << CLKPS2) |;

This for activating the clock on port PA3 and PA2.

Another thing I want to learn is analog to digital converter as my final project is an analog input.
Analog to digital converter in attiny have a lot of features like
- 10-bit Resolution - 1.0 LSB Integral Non-linearity - ± 2 LSB Absolute Accuracy - 13μs Conversion Time - 15 kSPS at Maximum Resolution - Eight Multiplexed Single Ended Input Channels - Twelve Differential Input Channels with Selectable Gain (1x, 20x)
- Temperature Sensor Input Channel - Optional Left Adjustment for ADC Result Readout - 0 - Vcc - ADC Input Voltage Range - 1.1V ADC Reference Voltage - Free Running or Single Conversion Mode

when I tried to use it I found that I can use it only on data register A.

This code shows how I activate it in port PA0 , PA1 ,PA2 , PA3 and PA4

ADMUX =  (0 << REFS1) | (0 << REFS0) // VCC ref     
   | (0 << MUX5) | (1 << MUX4) | (1 << MUX3) | (1 << MUX2) | (1 << MUX1) | (1 << MUX0); // ADC0 PA0
 ADCSRA = (1 << ADEN) // enable
     | (1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0); // prescaler /128

This a small part I have learned in micro-controller but I will continue in learning it.

What I want to learn

I want to learn how to use interrupts at first and then laern how to use timers.

One question of questions I have why I should connect component need to analog to digital converter in register A only?

programming the board

I decided to program the board I made in week Electronic design assignment

This board contain LED and push button so I decided to program it.

The goal of programming the board

The goal of programming the board is that by pressing the push button it turns the LED off.

Description of the programming process I used

For programming the board I will use the c language.

First thing I defined the speed of the oscillator I used in my case is 20 MHZ.
Then I defined the delay function #include<util/delay.h
I defined the input and output function #include<avr/io.h
I defined the pin connected to LED as output DDRA |= (1 << PA5);
I Defind the pin connect to push button as input DDRB &= ~(1 << PB2);
Then for input pin I should activate the pull up resistor PORTB = 0b00000100;
Then I defined the function I want the code to do .

while(1) {
 if (PINB &(1<< PB2))  
//if button pressed

 PORTA &= ~(1 << PA5);

else

 PORTA |= (1 << PA5);


       }

Now I finished the code then I should have the make file I download neil make file and modify on it.

Neil make file

After I had the the code file in C and make file I opened the terminal and start wrote sudo make program This to generate the hex file to upload it on the board and then for burn the fuses I write command sudo make fuses .

This image show that I successful upload the program to the board

This image show that I successful burn the fuses and the board ready for working

Now I finish the program and uploaded it to the board and the board working.

I use programming in c as I have full knowledge about arduino and I want to learn new things.

This video show the board working when I upload the code on it.