Re: [avr-chat] DAPA programming hardware options

[Stuart Longland (VK4MSL)]

Hi Richard,
On 30/09/12 12:04, Richard Cavell wrote:
> Hi, all.
> 
> I'm in Ipswich, Queensland, Australia.  I'm trying to learn AVR
> Programming by starting here:
> http://hackaday.com/2010/10/23/avr-programming-introduction/
> 
> […]
> 
> I built myself a DAPA cable.  Problem is, none of my computers has a
> parallel port.  I installed a 3rd party parallel port card (cheap
> Chinese rubbish) into a PCI slot on my desktop, but it turns out the
> driver is unsigned and probably doesn't work on Windows 7 anyway.

Ahh the joys of Microsoft dictating what you can and cannot install on
your own hardware.  Have you tried booting up a Linux LiveCD to see if
it can drive the parallel port?

You may also be able to expose the raw PCI device to a virtual machine
guest running a compatible OS if dual-booting isn't convenient.

> In order to follow this tutorial, I need a computer with a
> motherboard-mounted parallel port that will run avrdude and reliably
> program an AVR through it.  Any ideas what kind of computer/operating
> system would give me the most compatibility?  I guess I could go through
> ebay to buy an old computer, or find someone locally.

I built my own "DASA"-style programmer using some general-purpose
transistors that I find, works well on the old Toshiba TE2100 laptop I
have (running Gentoo Linux).  It does not work with a PL2303-based USB
serial converter, but that's another story.

The programmer I built involved 5 transistors; 4 BC547s and a BC557... I
can post a schematic up if anyone is interested.  RTS connects to a
BC547 which drives nRESET and the base of the BC557.

The BC557's emitter connects to the device's VCC, and the collector
provides the pull-up voltage on the transistors driving SCK and MOSI;
thus when nRESET is logic high, the PNP transistor is turned off, and so
as long as the other transistors are off, SCK/MOSI effectively go
high-impedance, so you can leave it plugged into a circuit.

The buffering also allows it to work at almost any voltage.  I've been
programming an ATMega8L with it running at 3V.

Jaycar sell all the bits needed.

A compatible system with the above programmer should be fairly easy to
come by, just look in any pawn shop ... I know Ipswich have a few. :-)

Regards,
-- 
Stuart Longland (aka Redhatter, VK4MSL)      .'''.
Gentoo Linux/MIPS Cobalt and Docs Developer  '.'` :
. . . . . . . . . . . . . . . . . . . . . .   .'.'
http://dev.gentoo.org/~redhatter             :.'

I haven't lost my mind...
  ...it's backed up on a tape somewhere.