gnupic: DIY USB programmer ?
Subject:
Re: DIY USB programmer ?
From:
Manuel Bessler ####@####.####
Date:
6 Jan 2005 03:07:41 +0000
Message-Id: <20050106040037.B27123@betazed3.varxec.de>
On Wed, Jan 05, 2005 at 12:09:06PM -0500, Byron A Jeff wrote:
[...]
> > parallel, and it's possible to reserve one for the firmware update without
> > need of rerouting the signals or needs for dedicated programming pins on the
> > MCU.
>
> I don't think speed is an issue. For the project the OP proposed, you'll only
> burn once. So it doesn't matter if it takes a minute or two.
Not necessarily just once, but not very often. One of my users with whom
I work closely (he is on windows, I do everything on linux) told me that
IC-Prog takes over 10min to program a PIC. (All thats really getting
burned there is just the bootloader which is <512 bytes. Not sure if
ic-prog always burns the whole chip or just the part thats actually
used)
Its a JDM type programmer that I built for him. The other issue that he
seems to have is that those JDM-type programmers don't work well with
some laptops due to the low serial port voltages.
Look for the table "Relative Programming times for the various programmers"
on this page:
http://www.sparkfun.com/tutorial/Programmer_Selection.htm
The PIC-PG2C/PG1 are JDM variants. It lists 10-15 minutes for a 18F452
with 32k mem.
Of course this is just a Windows issue. But several of my users are on
windows :((
[...]
> > possible, annother possibility is to connect a dry 12V or a new 9V battery to
> > the reset pins with only one resistor to protect the port, in the case the
> > reset pin is set as output without startup delay, this for the 10f-16f
> > parts.
>
> I think you have a skewed vision of the purpose of the project. From my
> reading from the OP this is a single use standalone programmer for a
> flight simulator console. It's not an ICSP programmer for general use.
> It's a one shot one off programmer.
Yes, I need a simple programmer, not for development work. Maybe for
programming once a few PICs and then be done with it. Maybe later for
updates as long as not all boards have bootloader capability.
The programmer should have sockets for at least 40/28pin pics and a ICSP
header. Like the olimex PG2C I mentioned before:
http://olimex.com/dev/pic-pg2c.html
> So it doesn't matter how RX and TX are connected. Jumpers and the like are
> not relavent. Neither is the voltage doubler, a 9V battery as you propose
> should be fine for a one off. Reason being is that you can use the one off
> programmer to dump a bootloader into the chip, then you don't need a programmer
> anymore.
Couldn't the issue of a voltage doubler be solved like it is in the JDM
programmer ? When we use a USB-to-serial converter, we might have those
+/-12 V (assuming those adapters use a MAX232 look-a-like)
> The goals are to keep it dumb, simple, and cheap with easily available parts.
> And nothing is dumber, simpler, cheaper, or more available than a 555 timer,
> along with a handful of resistors, transistors, caps, and diodes.
This would be a winner(-programmer) :)
Manuel
--
Opensource/Free Software: No Gates, No Windows
