# Atmega USB programmer

#### sam_logan87

Joined Aug 21, 2008
9
Hello i was wondering if anyone can help. I have built a robot using a Atmega8 microcontroller. Like most people i am moving on with technology and no longer have big bulky parallel or serial ports on my laptop, my only computer. Does anyone have a schematic of any sort that allows for programming the chip with usb, as I would like to do a bit more programming without having to go to university to use the computers there that do have parallel ports. I don't really want to fork out sums of money to by pre made programmers as i am a poor univeristy student.

Cheers
Sam

#### hgmjr

Joined Jan 28, 2005
9,029
There are a number of inexpensive USB to 25-pin parallel port adaptors on the market. Be careful to make sure that the parallel port connector is not the Centronics version.

hgmjr

#### mik3

Joined Feb 4, 2008
4,846
Hello i was wondering if anyone can help. I have built a robot using a Atmega8 microcontroller. Like most people i am moving on with technology and no longer have big bulky parallel or serial ports on my laptop, my only computer. Does anyone have a schematic of any sort that allows for programming the chip with usb, as I would like to do a bit more programming without having to go to university to use the computers there that do have parallel ports. I don't really want to fork out sums of money to by pre made programmers as i am a poor univeristy student.

Cheers
Sam
I bought TOP2049 programmer for 70 UK pounds.

If you want to make one search in google for usb programmers circuit

#### sam_logan87

Joined Aug 21, 2008
9
hello,
what is the difference between the centronics and others. I know that some work and some don't but have struggled to find anyone who would tell me which one to buy. Do you have one particular brand to buy or are they called something different from the ones that don't work.

Cheers
Sam

#### hgmjr

Joined Jan 28, 2005
9,029
The Centronics version is intended to be used to connect directly to centronic compatible printers.

The standard 25-pin D-SUB connector types will mimic the standard IBM-PC 25-PIN parallel port.

hgmjr

#### John Luciani

Joined Apr 3, 2007
477
You should see if the Arduino bootloader will work with the Atmega8. I know it works
with the ATmega168. With the bootloader you can use an FTDI USB to RS232 cable
to program the uC.

With the bootloader you could also add a USB port to your robot using the FTDI FT232RL
IC. I have a schematic for the USB circuit in the ZB1 datasheet at http://tinyurl.com/5rfmrz

(* jcl *)

#### sam_logan87

Joined Aug 21, 2008
9
so any other adaptor will do??
Cheers
Sam

#### nanovate

Joined May 7, 2007
665
Atmel's AVRISP Mk2 is also a USB programmer ~$35 #### hgmjr Joined Jan 28, 2005 9,029 Atmel's AVRISP Mk2 is also a USB programmer ~$35
I have also had experience with the programmer above and it works well. You can download AVRSTUDIO4 for free from ATMEL's website to use in conjunction with this programmer.

hgmjr

Joined Nov 23, 2008
1
Here are a few that I found while I was searching one for my needs....
As you will see there are usually two approaches.
1) Use a USB-Serial chip in the circuit (Usually FT-232BM)... Then feed the Serial Output to the programming AVR (Can be any AVR as long as it has a serial port and supports SPI programming). This controller will program your AVR through ISP ( MOSI, MISO and SCK lines). Examples of such programmers are
http://www.serasidis.gr/circuits/usbAvrProg/usbAvrProg.htm
http://tuxgraphics.org/electronics/200510/article05101.shtml

2) Use a USB driver implemented in the AVR. In this type of programmer the USB signals D+ and D- are fed directly to IO lines of the programmer(of course with some passive components). In this case there is no need for a FT232BM chip. Examples of such programmer includes
http://www.fischl.de/usbasp/
http://www.obdev.at/products/avrusb/avrdoper.html

each has its own drawbacks and advantages.....