hello again freinds.....i want to make a programmer for AVR using USB input from my LAPTOP...I DO NOT WANT TO BUY AN ALREADY DESIGNED PROGRAMMER OF THIS TYPE as suggested in most of the forums...how do i go about it...

 

..I DO NOT WANT TO BUY AN ALREADY DESIGNED PROGRAMMER OF THIS TYPE...

As with many things in real life, one cannot make a similar product cheaper and better.

You need to tell us why you would want to build one instead of buying one.

You probably don't realized that a USB programmer usually requires a PIC or AVR which itself must be programmed with the required binary code first before they can work to program other MCUs.

 

AYou probably don't realized that a USB programmer usually requires a PIC or AVR which itself must be programmed with the required binary code first before they can work to program other MCUs.

i dint get u..can u help me understand the concept....it wil be a great help...

 

USB communications are somewhat complex and need a dedicated device to control things - http://www.faculty.iu-bremen.de/birk/lectures/PC101-2003/14usb/FINAL VERSION/usb_protocol.html

http://en.wikipedia.org/wiki/Universal_Serial_Bus

http://www.intel.com/technology/usb/spec.htm

 

Hello,

On usb.org you will find more official info:
http://www.usb.org/home

Bertus

 

This is like a chicken and egg paradox. In order to build a USB programmer, you need to program a microcontroller as the control unit in the USB programmer. It will be an interesting project. But in the end you will find out that the sum of money you used at the DIY programmer will be pretty much the same as the cost of a simple commercial one. It is hard to beat mass production. Besides I suspect that both Microchip and AVR sell the hobbyist programmer with very little profit.
So why do you net want to buy one?

 

If you have a friend that has a AVR programmer, you can program a chip to do the USB communications.

And with the AVRs thats support ICSP, the programmer you build with the help of a friends programmer can communicate with USB then ICP the target chip.

 

Here is one type simple USB programmer for AVR. http://www.fischl.de/usbasp/
You can also google this -> avr usb programmer. You could aslo implement a boot loader like this http://www.fischl.de/avrusbboot/
But in both cases you still have the "chicken and egg paradox" Both need pre programming in order to work

 

@t06afre----------because i would like to know the actual working of the USB programmer..the practical problems...and will LUV to make it work myself...

 

You can use an USB to RS232 converter (like FTDI 232R) and the serial programmer used by Pony Prog (software and schematics on site, freeware , no microcontroller needed).