4. Hardware used in Microcontroller programming

Earlier I told you that the file generated by us using a computer, has to be write into the microcontroller memory using a circuit which connect microcontroller and the computer.
So there are very expensive devices in the market for this purpose but here I'm giving you a very simple circuit which you can build your own.

This is the item list
1. Rs 232 female connector-  1
2. Resistors                  1.5k - 1
                                     10k - 1
                                   
3.Zenor diode  - 8.2v  - 1
                            5.2v - 1
4. IN 4001 diode - 4
5. Bc 547  - 2
6. 100uf  - 1    22uf- 1
7. 18 pin Zip socket - 1

So what you have to do is to buy above items and get those connected mentioned as above. Make
sure you identify correct pins in diodes, transistors, and capacitors and also Rs232 9 pin serial connector.
You should make sure to make this hardware correctly because you will need this more frequently and without this you can't run your programs. So follow these instruction to make it correct.

* Rs 232 female connector

So this is the port what you should connect to the computer via it's serial port. If your computer does not have a serial port you'll have to get a computer where a serial port in built or you can get serial port card and connect to the computer. There are usb programmers and priter port programmers you can make. If you need more assistance please let me know.
This is it's pin configuration.

Additionally if you have a Rs232 male female cable you can easily connect it to the computer.

Later i will tell the mechanism of these ports and many more application you can make using these ports with microcontrollers. Be patient let's begin with the basic.



*  Resistors have color code and make sure that you get correct one.

* Diodes and zenors have cathode(-) and anode(+)

* BC 547 transistor

*  18 pin zip socket
Advantage of using this is you can use a microcontroller without damaging pins.

3. Software use in Microcontroller programming

Before go into more detail you should know categories of  programming software.
Those are


1. Machine languages
2. Assembly languages
3. High level languages

This is a code that use in machine language

01001010000011

Only machine(microcontrollers....) can understand this. So this is machine language and we can't use this to program microcontrollers because only 1 and 0 is used. But above code is write in  an assembly language it is like this

Bcf STATUS,5

So what does it mean. It means that to convert 6th bit of status register to 0(zero). So we can use assembly language to write programs. But this is also difficult to understand. I'll tell the reason as we go on. In high level languages like Mikroc which is developed by C language, it is very easy to understand and writing language because it's code  names are are familiar to english language and in few minutes you can write a big program. But there are prolems also. When we are using highlevel languages it's difficult to understand what is happening inside microcontroller. So some times it difficult to make correction. And other thing is high level languages use comparatively large program space. So limited memory of a microcontroller some time is wasted using highlevel languages. You will understand these when we are writing programs. So in my lessons I use assembly language but later I use high level language so you can master in programing in both languages. Remember if you want to be a good programmer you should know assembly very well. You will understand this as we go on \. So whether it's difficult to learn assembly language we should start to learn it.
Some assembly software are very expensive but we are going to use PIC microcontrollers and using MPLAB software which can be downloaded freely we can write programs for that. So you should download this software and install to your PC.
This is the link for that.

http://ww1.microchip.com/downloads/en/DeviceDoc/MPLAB_IDE_8_83.zip

This is the interface of it. Do not worry we are going to get familiar with it.

After we finishing the writing program  MPLAB convert it to a *.hex file which contains machine language codes. This process is called compiling. After compiling we have to insert that file to the microcontroller. We can use MPLAB for this but the problem is compilers which is a circuit that connect to the computer to facilitate writing program to microcontroller. But there are cheap compilers which you can make your own for 2-3$. But you have to download another software but it is also freely available. This is the link and get it downloaded.

http://www.winpic800.com//descargas/WinPic800.zip

This is it's interface

So I hope you will download these two software and be ready with it when we meet next time.
In next lesson i will write on hardware that you are going to need when you are doing microcontroller programming.

See you soon.

2. Introduction to the Microcontrollers

What are micro-controllers? Some of you may not know about it. But in the near future everyone will know about it because these days most of electronic instruments are made by using micro-controllers. Examples for those kind of instruments are motor cars, toys, cd/dvd players, radio, camera etc.
But in your real life you will need this to create your own circuits. For an example
Think that you want to measure current supply to your home and if voltage is above than what you want you can cut down the electricity until it get corrected. Pretty interesting ah!


As for learning purposes I use PIC 16F84A,628A,877A microcontrollers and those are around Rs.500(5$) in the market so anyone can practice this without much problems.


What is a microcontroller?


It is an IC(Integrated Circuit) also  it looks like an IC. This is a picture of a microcontroller which i am going to use in lessons.

But here not as normal ICs we program microcontrollers and we convert it to an IC we want. But we need to have a computer to write programs to microcontrollers and a special gadget to insert that program into the microcontroller. Later I will give you the guidance to make a similar gadget which is very expensive in the market. But do not worry because you need just less than Rs.200(2$) and I will tell you what to do in next lesson.
Actually microcontroller is a computer because it has a processor, memory, and a data source. So this is similar to a system unit of a computer. But the processing speed is very much low compare to the microprocessor in computers. But for our purposes this is more than enough.
So I think now you know something about microcontrollers. You will gain more knowledge on this as we go on.
 There are pins as a usual IC in a microcontroller but the difference is that you can use any output input as you like not as in IC which is previously defined.

So microcontroller communicate with outside with these input and output pins. In this pictures I have shown you a PIC microcontroller named PIC16F84A which is going to be used in my basic lessons.



Each and every microcontroller these input and output pins are grouped. As an example in PIC1684A has 5 pins grouped as PORTA (pin number 17,18,1,2,) and 8 pins groupe as PORTB (pin number 6,7,8,9,10,11,12,13). So this has 13 input/output pins. You can use these 13 pins to control the circuit you make. Let's say that you want to make a blinking LED , you can use any of above 13 pins and make your circuit.

I will explain how to do that in little later in my next lessons. You may noticed that there other pins also in the microcontroller and those are for giving power supply and clock impulses to the microcontroller.

Microcontrollers are executing programs according to the clock impulse given to it. Example of a clock impulse is given below.

In PIC16F84A you should give this impulse to pin 16 and 18. 

Don't worry with lessons you will understand everything.

This is how you should give the power supply to the microcontroller. When you give power to the circuit it execute the program written inside it by us. 

You will understand everything as we go on. Do not worry. I'm giving these here for completeness.


So now I think you have some kind of basic knowledge about microcontrollers. You will understand everything as we go on because i will teach you everything with free of charge. 


So see you in my next lesson which is about softwares you should use in microcontroller programming.
Please give me comments , suggestions, and if you have any problem please just ask.

1. Let's Learn Micro-controller programming

HI for all srilankan and others. I am starting this site because I am going to tell you how to make learn microcontroller free of charge. I am starting from the very much basic steps and planning to go in to deep areas of the subject.

Have you ever seen a knight rider circuit. I know most of you have created it and had a wonderful experience in your childhood. In that circuit you have to buy 4017 ic.

But you can make any circuit including knight rider circuit and very much complex circuit from a single IC that is PIC micro controllers. How interesting it is? What you have know is that ability to write programs from your computer to the microcontroller and put that program into the IC and put that into the circuit. That's all. It looks simple but initially you should know

1. Basic ability to operate a computer
2. Write programs to the IC using appropriate software(MPLAB) and convert that into machine language.
3. Simple programar that connect to computer to insert that program you create to the IC
4. Making the circuit according to the program you write and insert IC to the circuit

I'm sure that most of you may not know these A-Z. But from this blogger site I tell you every thing that you should know if you want to be a microcontroller programmer. Don't be afraid I'm starting from the very first beginning and continue to post more complex things as you can understand.
So in my next post i will tell you an introduction to the microcontrollers.
See you soon