gnupic@linuxhacker.org

On Thu, May 29, 2003 at 09:57:25PM +0100, Manwlis Giannos wrote:
> 
> 
> >Leva <leva@interware.hu> wrote: 
> 
> > OH! Too complicated! My TLVP programmer has only one active device and one
> > resistor. It's also a Tait style design:
> 
> Ok. Now take a look at Tait's programmer, and your HVP programmer. If you add
> the 7805 and 7812, the 100nF capacitors, diodes to your HVP programmer you get
> almost the same amount of components.

But there's no need to add those components. All of the Trivial Programmers
operate under the principle that power can be derived from the PC.

The THVP programmer only does flash parts. See an explanation from Bob Blick
as to why. All flash parts use the Vpp line as a signal, not for actual power.
Also in the datasheets for all of the common current parts, Vpp is minimally
specified as Vdd+3.5V. The upshot is that 12V is a solid Vpp signal.

Any non laptop PC will have both +5V and +12V easily accessible via a disk
connector.

Also the TLVP programmer is low voltage only, needing only 5V, which is 
accessible from any number of connectors on the average PC.

The point is that the programmer is pretty much useless without the PC and
frankly PC ooze clean regulated power.

> 
> Just to add, I know the 'passive' programmer which gets power from the serial
> line. As an engenear I do not like this kind of simple circuit. It's more safe
> to hava a little more complicated, but more reliable stuff. But this is my own
> philosofy.

Serial isn't a valid power interface due to both voltage and current 
variations. I don't believe that I ever suggested that it was.


> 
> 
> > Note that you can find both a High Voltage and ICSP version there too. Works
> > great the 16F62X and 16F87X parts. As soon as I get my 18F452 samples I plan
> > to extend my version of Brian Lane's picprg2.3 to program those too.
> 
> I'm glad to hear that! Please share us your 18fxxx softwares and hardware
> experiences!   

As everything else PIC related anything I make progress on (and in fact just
got my sample shipping dates of Monday and the Monday after that) will be
posted on my site: http://www.finitesite.com/d3jsys

> 
> 
> 
> 
> Some (5) months ago I posted a message concerning the pic18f series o
> programming. I modified the Brian Lane's "picprg2.3-c" sw, 
> which works with external configuration files for each device,

I think that was Carlos Onega's fork. From his site at http://picprg.sf.net
he has abandoned work on it. Up until now I've stayed relatively close to
Brian's original code, because personally I found that the overall structure
of the application was sufficient for my task.

The two general issues I had with that fork was that Carlos wanted a generic
device programmer, and that instead of separating algorithms and device
specifications (memory size etc.) he collapsed them both into the config files.
PICs only have about 5 or 6 different algorithms with the same basic structure.
My thought is that it would be better to put those algorithms in code instead
of complicating the codebase parsing a bunch of data.

I'll let you know how it turns out. Hmmm Maybe a compiler for Carlos' 
config file format is the ticket!

> and for now it works with the pic18f452 device. The only restriction is that 
> the configuration fuses can be programmed only from within the code (
>"__CONFIG" proper directives). I use the well known "TAITish" parallel
>programmer with the 4066 and 7406 ICs. I just added 2 capacitors very close
>to the pic18f452 because the programming algorithm is a little bit fast. You
>can experiment with the code located in:  

> 
> http://morgoth.tlc.upv.es/~hecormar/pic18f/

Thanks for the pointer.

BAJ