Atmega USB programmer

Thread Starter

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
9,027
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
4,843
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
 

Thread Starter

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
9,027
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
475
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 *)
 

imarshad

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.....
 
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