Mechanical EngineeringFAB laboratory →List Of Experiments

Interface & Application Programming

PREREQUIST

- For better understanding of experience candidate should aware of basic understanding of Microcontroller.
- SMD (Surface Mount Devices)
- Basic knowledge of C-Programming and assembly language

WHAT IS MICROCONTROLLER

A microcontroller (MCU) is a small computer on a single integrated circuit containing a processor core, memory, and Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM. Microcontrollers are designed for embedded applications, in contrast to the microprocessors used in personal computers or other general purpose applications.
The AVR Micro-controllers are easy to use and to control anything you put mind into like Motors, LCD, LEDS & Other stuffs. You can even make boards that can control machines and media components. Here we will be looking at some schematic of circuits that can be done just to control anything. the AVR circuit that can be build to control anything and to give a light of how they can be used to develop any project you want to build or you plan to make like flashing led's.

What is ATMEL?

Advanced Technology Memory and Logic (ATMEL) Atmel Corporation (Nasdaq: ATML) is a worldwide leader in the design and manufacture of microcontrollers, capacitive touch solutions, advanced logic, mixed-signal, non-volatile memory and radio frequency (RF) components. Leveraging one of the industry's broadest intellectual property (IP) technology portfolios, AtmelA is able to provide the electronics industry with complete system solutions focused on industrial, consumer, security, communications, computing and automotive markets.Depends on the company here under some examples are given produces by Atmel so each MCU name starts from AT.Microcontroller are categorized of ATTiny & ATmega family
ATMEL PRODUCED many families of MCU in that tinyAVR, megaAVR, Xmega etc.

- ATTINY45/13
- ATTINY26
- ATTINY44
- ATMEGA88

AVR is stands for : According to the Atmel AVR stands for nothing. But other says that it stand for : Advanced Virtual Risc(AVR)

ISP-AVR PROGRAMMING(ISP : In-System programmer)

AVR ISP Programming requires only the SPI(serial peripheral interface)interface of the microcontroller as outlined below.That means all AVR processor with SPI port/ interface can be ISP programmed. In this article ATTINY45 is the target processor as an example. Most AVR microcontrollers can be programmed using this method. This is a very easy and economical way of programming microcontrollers. Only a parallel port programming cable is required (self made). Only two application software’s needs to be installed:

“gavrasm” for assembling and compiling a hex file
“avrdude” for downloading hex file to the target microcontroller

Compiling and downloading hex file to the microcontroller is done on the Linux terminal.


Fig 1- ISP PROGRAMMING CONNECTION



All this was done using a computer running on Linux operating system. This programming method applicable to all AVR microcontrollers, which means that the tiny26 used in this application can be substituted with other AVR processors.

ISP-PROGRAMMING CABLE

What is ISP(in system programmer) PROGRAMMING: ISP (In System Programming) will provide you a simple and affordable home made solution to program and debug your microcontroller based project Only five lines (signals) are required to ISP-program a target microcontroller. ISP programming uses- SPI interface to download the hex file into the target microcontroller.

The target pins on the microcontroller are

- MOSI : DATA INPUT
- MISO : DATA OUTPUT
- SCK : CLOCK INPUT
- RESET : USED TO ACTIVATE SERIAL PROGRAMING EVEN USED TO RESET DEVICE, TO ACTIVATE3 PINS (MOSI,MISO,SCK)
- GND : DROPED VOLTAGE, GOES TO GROUND

TO MAKE THE INTERFACE CABLE THE REQUIRED COMPONENT ARE:

- 5-pos vertical AMP MTA connector (RIBBON CABLE CONNECTOR)
- 5-pos vertical SMT pin header
- Ribbon cable
- DB25-male connector


Fig-2





PROCEDURE FOR HOW TO MAKE INTERFACE CABLE

- Hold the 5-pos SMT MTA (male) pin header with its two pins facing to you, just like it is shown in the above diagram.
- Take a ribbon cable, connect it to the DB25-male connector/plug (only five wires are needed as showed in the diagram below)
- only five pins of the DB25 -Male connector to the AMP MTA Plug need to be wired together
- Start by connecting the required five wires to the DB25 -Male connector(Pin7,Pin 8,Pin 9,Pin 10 & Pin18) prefer soldering them directly to the pins (avoid over heating the connector since they can damage/deform the connector)
- Now connect the five wires from DB25-male connector to the AMP MTA plug as outlined below

Here are the pins of the two connectors to be wired together
- DB25-pin 10 >> To AMP MTA Plug Pin 1
- DB25-Pin 18 >>To AMP MTA Plug Pin 2
- DB25-Pin 9 >>To AMP MTA Plug Pin 3
- DB25-pIN 7 >>To AMP MTA Plug Pin


Fig 3- ATTINY 45- AVR –ISP PROGRAMMING

The diagram above shows how the 5-position MTA-connector/header should be connected to the target AVR (the ATTINY 45).