gnupic: DIY USB programmer ?
Subject:
Re: DIY USB programmer ?
From:
Byron A Jeff ####@####.####
Date:
6 Jan 2005 12:40:16 +0000
Message-Id: <20050106124013.GB15279@cleon.cc.gatech.edu>
On Wed, Jan 05, 2005 at 05:49:02PM -0600, Kevin L. Pauba wrote:
> Byron A Jeff wrote:
>
> >On Wed, Jan 05, 2005 at 09:19:15AM -0500, Byron A Jeff wrote:
> >
> >[snip]
> >
> I've always been intrigued by the serial ascii programmer:
>
> http://www.piclist.org/techref/com/picnpoke/www/http/projects/prog.html
>
> I think it passes the "Radio Shack" test. I built one up and, as I
> recall, it worked. I have some Java code around that drives it too.
>
> What do you think?
That's the concept that I had seen before. My quick mock up is the same
except using the 555 as the monostable which simplifies the wiring a bit.
I was hoping to get it to run 4 times faster. Some quick calcuations with
a 555 monostable calculation indicates that a 1K resistance and a 1 uF
cap should get you right around a 1ms delay. At 4800 BPS the cell width
is 208 uS. So 10 cells is 2.08 ms. 1ms puts you near the center of
a character transmission.
BAJ
