Re: [avr-chat] ultra-cheap HVSP programmer

[Nicolas Boullis]

Hi,

On Fri, Mar 28, 2008 at 01:36:13AM +1000, Neil Davey wrote:
> You can program the chip using ISP as much as you like, until you 
> program the fuse to disable the reset function of PB5.
> It won't act as a GPIO until you do that though.. Once you've programed 
> the fuse to disable the reset function, then you will need HVSP to 
> reprogram the chip (and also can reset the fuse IIRC, please correct me 
> if I'm wrong)

That's good news. So I guess I will program my chip with a programmer 
made of a few resistors, and the hope I won't have to reprogram it 
later.


> Is just getting an STK500 an option for you? It provides HVSP capability.

On Thu, Mar 27, 2008 at 06:30:34PM +0100, Joerg Wunsch wrote:
> 
> Even cheaper: an AVR Dragon.


Well, what I'm willing to build is worth around $10. As far as I can 
see, an STK500 or an AVR Dragon cost around $50, so I consider them 
quite expensive for my use...

Is there any reason why it would be impossible to build a HVSP 
programmer out of a parallel port plus a few off-the shelf components 
(at least a transistor to switch the high voltage, and a regulated 12V 
power supply), and rely on the computer software to perform all the 
bit-banging?


Cheers,

Nicolas