PROGRAMMING AVR ON BREAD

BOARD

Jatinder Singh Chhabra(200601120)

Digvijay Singh (200601128)

PROGRAMMING AVR ON BREADBOARD

Programmer Circuit

Circuit which is used to program a micro controller

There are various techniques in practice and all of

them have their own advantages and

disadvantages

INDEX

LVP – Low Voltage Programming

HVSP – High Voltage System Programming

JTAG – Joint Test Action Group

LOW VOLTAGE PROGRAMMING

Also called - In System Programming

Program micro-controller on chip along with all

peripheral devices

Via SPI at working voltage of 2.7-6 V

Needs VCC, GND, RESET and 3pin for SPI

LOW VOLTAGE PROGRAMMING

Advantages:

Less chance of accidental damage

No need for separate power supply

Dis-advantages:

If fuse bits like reset when disabled than LVP cannot be

done

LOW VOLTAGE PROGRAMMING

Note:

Accidentally fuse bits changed and than high

voltage programming is needed

JTAG

Joint Test Action Group

Standard Test Access Port

Boundary-Scan Architecture

method for testing interconnection (wire lines) on printed

circuit boards

Used as an IC debug or probing port

JTAGEN Fuse needs to be enabled

JTAG

Break and step in functions for extensive on-chip

debugging

HIGH VOLTAGE PROGRAMMING

12V is applied to the RESET pin

All AVR devices can be programmed

The device is taken out of the system

HIGH VOLTAGE PROGRAMMING

Advantages

Work even if fuse bits are set

Some devices can only be programmed using HVSP

Disadvantages

Need two different power supplies

12V can damage if there is current leakage

Need to remove all peripheral devices

COMPUTER INTERFACE

USB

Serial Port(RS232)

Parallel Port

SERIAL

Can be connected to SPI or USART

High Voltage circuit is complex and shown only for

completeness

http://electrons.psychogenic.com/modules/arms/art/5/AVRInSystemProgrammer.php

SERIAL LOW VOLTAGE PROGRAMMING

CIRCUIT

SERIAL LOW VOLTAGE PROGRAMMING

CIRCUIT

http://www.scienceprog.com/avr-serial-and-parallel-high-voltage-programmer/

DAPA

Programming done through SPI

Parallel port is easily available on most of Systems

Pros and cons

Very simple circuit and cheap implementation

Keep parallel port cable short because clock is also

transmitted(SPI)

Command to check if circuit is ready

# uisp -dprog=dapa

Output : - Atmel AVR ATmega32 is found.

100 Ω resisters are used to protect uC from voltage

spikes

DAPA CIRCUIT

http://www.captain.at/electronics/atmel-programmer/

USB PROGRAMMER

Latest Generation of Programming Circuits.

Support for Universal Serial Bus (USB).

Programming done through SPI interface.

USB PROGRAMMER

http://www.ladyada.net/make/usbtinyisp/parts.html

USART

Programming possible with Boot loader

Fuse bits cannot be changed

Useful for program upgrades

USART PROGRAMMERS

Some Programmers come bundled with

microcontrollers which have bootloader installed on

them.

Their Programming circuit could be made extremely

simple.

Example is a microcontroller with USART

bootloader preinstalled can be programmed with 4

wires Vcc, gnd, Tx, Rx.

Negative point here will be that bundling software

on pc will also have to be constructed as default

programming softwares like avrdude or uisp may

not understand the underlying protocol.

SOFTWARE

With all the above circuit one requires a software on

computer.

Linux

Uisp

avr-gcc

Windows

Avr-studio

ponyprog

NOTE

Accidental changing fuse bits

Need to take care fuse bits get changed by mistake

Voltage Spike protection

High Baud rate need Crystal oscillators

Do not push an IC forcefully into the breadboard

REFERENCES

http://www.lancos.com/prog.html

http://electrons.psychogenic.com/modules/arms/art/

5/AVRInSystemProgrammer.php

http://www.scienceprog.com/avr-serial-and-parallel-

high-voltage-programmer/

http://support.atmel.no/bin/customer?=&action=vie

wKbEntry&id=343

http://www.captain.at/electronics/atmel-

programmer/