Hi,

I would like to incorporate a DAC in a board design so as to provide
some biases in the rest of the circuit and was wondering if anyone
knows if any company provides software that could program their DAC
through the serial or parallel port. Unfortunately, there is not much
time for designing and testing so I don't have time to write the
program myself. There are no tight specifications on the DAC
(preferably running at 3.3V and accuracies of 10bits and up are fine)
so basically any DAC will do as long as it has ready software to
program it.

Thanks in advance for any suggestions.

Hi, I guess you need to look for the sample program from the
microprocessor datasheep or application note. If you are using PIC,
perhaps you can find the program from the microchip website or just
google it. Good luck!

Sorry, I forgot to mention that I meant discrete DACs rather than
embedded into a microprocessor. Ideally I would like 8 of them in one
package. LTC and Analog Devices have some but the software they
provide is meant only for their evaluation kit.

On Apr 1, 6:03 pm, nyboard <lizong...@gmail.com> wrote:
> Hi, I guess you need to look for the sample program from the
> microprocessor datasheep or application note. If you are using PIC,
> perhaps you can find the program from the microchip website or just
> google it. Good luck!

On Apr 1, 8:08 pm, donald <Don...@dontdoithere.com> wrote:
> DL wrote:
> > Hi,
>
> > I would like to incorporate a DAC in a board design so as to provide
> > some biases in the rest of the circuit and was wondering if anyone
> > knows if any company provides software that could program their DAC
> > through the serial or parallel port. Unfortunately, there is not much
> > time for designing and testing so I don't have time to write the
> > program myself. There are no tight specifications on the DAC
> > (preferably running at 3.3V and accuracies of 10bits and up are fine)
> > so basically any DAC will do as long as it has ready software to
> > program it.
>
> > Thanks in advance for any suggestions.
>
> This does not make any sense.
>
> What processor are you using ?
> What is it programmed in, C, Assembly, Forth, BASIC, FORTRAN.... What ??
>
> You don't have time to do it right, but you must have enough money to do
> it over.
>
> good luck
>
> donald

The fact products get designed and sold with such a lackadaisical
attitude is mind boggling. I expect this in software, but not
hardware.

Personally, this sounds like an application for those digital
potentiometers made by Microchip and others. Also, 10 bits for bias
sounds excessive. If trim is being done, you get close with resistors
then tweak with the pot.

DL wrote:
> Hi,
> 
> I would like to incorporate a DAC in a board design so as to provide
> some biases in the rest of the circuit and was wondering if anyone
> knows if any company provides software that could program their DAC
> through the serial or parallel port. Unfortunately, there is not much
> time for designing and testing so I don't have time to write the
> program myself. There are no tight specifications on the DAC
> (preferably running at 3.3V and accuracies of 10bits and up are fine)
> so basically any DAC will do as long as it has ready software to
> program it.
> 
> Thanks in advance for any suggestions.

This does not make any sense.

What processor are you using ?
What is it programmed in, C, Assembly, Forth, BASIC, FORTRAN.... What ??

You don't have time to do it right, but you must have enough money to do 
it over.


good luck

donald

<m...@sushi.com> wrote in message 
news:6...@59g2000hsb.googlegroups.com...
> The fact products get designed and sold with such a lackadaisical
> attitude is mind boggling. I expect this in software, but not
> hardware.

I expect the O.P. is a hardware design guy and someone else will (eventually) 
do the software, hence he's trying to shorten his own schedule since all he 
needs to do is verify he wired up the hardware the right way and the software 
guy can write the "real" code.

Joel is partly right. I indeed am a hardware design guy, but there is
nobody else who will do the software. So it should be either available
by the company that makes the DACs or I have to write it on my own.

I have programmed in the past similar devices (e.g. ADCs) and one can
directly program them using a computer and the parallel or serial
port. The program can be written in any language and is easy in its
concept. The problem is that I don't have time much time and that's
why I was wondering if there is a ready solution.

m...@sushi you are right. A 10bit accuracy is not needed but 10bit (or
actually 8bit) is the lowest you can find available anyways for a DAC.
Using pots to tweak the bias values has the problem of drifting and
adjustment is needed every once in a while. DACs don't have this
problem and if ones with memory are used, then they just need to be
programmed once and not every time the power is turned on. Another
aspect is that I need 8 biases and therefore an octal DAC will use
much less space than 8 pots.

So basically my question in the post was if anyone has used or knows
of a simple program that runs on a PC and uses parallel or serial
interface and that can directly provide the right sequence of signals
for a DAC to be programmed. A microprocessor or microcontroller is not
needed.

Any help will be greatly appreciated.


On Apr 2, 9:43 am, "Joel Koltner" <zapwireDASHgro...@yahoo.com> wrote:
> <m...@sushi.com> wrote in message
>
> news:6...@59g2000hsb.googlegroups.com...
>
> > The fact products get designed and sold with such a lackadaisical
> > attitude is mind boggling. I expect this insoftware, but not
> > hardware.
>
> I expect the O.P. is a hardware design guy and someone else will (eventually)
> do thesoftware, hence he's trying to shorten his own schedule since all he
> needs to do is verify he wired up the hardware the right way and thesoftware
> guy can write the "real" code.

On Tue, 01 Apr 2008 17:24:32 -0700, DL wrote:
> 
> I would like to incorporate a DAC in a board design so as to provide
> some biases in the rest of the circuit and was wondering if anyone
> knows if any company provides software that could program their DAC
> through the serial or parallel port. Unfortunately, there is not much
> time for designing and testing so I don't have time to write the
> program myself. There are no tight specifications on the DAC
> (preferably running at 3.3V and accuracies of 10bits and up are fine)
> so basically any DAC will do as long as it has ready software to
> program it.

"Program" a DAC??? Why not just get one with a parallel interface and
write to the silly thing? For example, one I remember from cave-man days
is the MC1488, which just has 8 input pins, and when you write your
data to it (via a latch, probably), it just puts out the corresponding
current, which can be converted to a voltage with a resistor.

Good Luck!
Rich

On Tue, 01 Apr 2008 19:45:18 -0700, miso wrote:
> On Apr 1, 8:08 pm, donald <Don...@dontdoithere.com> wrote:
>> DL wrote:
>>
>> > I would like to incorporate a DAC in a board design so as to provide
>> > some biases in the rest of the circuit and was wondering if anyone
>> > knows if any company provides software that could program their DAC
>> > through the serial or parallel port. Unfortunately, there is not much
>> > time for designing and testing so I don't have time to write the
>> > program myself. There are no tight specifications on the DAC
>> > (preferably running at 3.3V and accuracies of 10bits and up are fine)
>> > so basically any DAC will do as long as it has ready software to
>> > program it.
>>
>> > Thanks in advance for any suggestions.
>>
>> This does not make any sense.
>>
>> What processor are you using ?
>> What is it programmed in, C, Assembly, Forth, BASIC, FORTRAN.... What ??
>>
>> You don't have time to do it right, but you must have enough money to do
>> it over.
> 
> The fact products get designed and sold with such a lackadaisical
> attitude is mind boggling. I expect this in software, but not
> hardware.
> 
> Personally, this sounds like an application for those digital
> potentiometers made by Microchip and others. Also, 10 bits for bias
> sounds excessive. If trim is being done, you get close with resistors
> then tweak with the pot.

It sounds like f'in homework, is what it sounds like.

Thanks,
Rich

On Wed, 02 Apr 2008 14:36:56 -0700, DL top-posted:
...
> So basically my question in the post was if anyone has used or knows
> of a simple program that runs on a PC and uses parallel or serial
> interface and that can directly provide the right sequence of signals
> for a DAC to be programmed. A microprocessor or microcontroller is not
> needed.

There is no program needed. No program at all, other than the ability
to output an 8-bit byte out the parallel port. And latch it, of course,
but that's hardware.

Latch the byte, and give it to any ordinary 8-bit DAC - Digi-Key has
hundreds, if not thousands, of them to pick from. Output the byte
through  the port, latch it, let the converter convert it, and you're
done!

And don't top-post.

Good Luck!
Rich

> 
> Any help will be greatly appreciated.
> 
> 
> On Apr 2, 9:43 am, "Joel Koltner" <zapwireDASHgro...@yahoo.com> wrote:
>> <m...@sushi.com> wrote in message
>>
>> news:6...@59g2000hsb.googlegroups.com...
>>
>> > The fact products get designed and sold with such a lackadaisical
>> > attitude is mind boggling. I expect this insoftware, but not
>> > hardware.
>>
>> I expect the O.P. is a hardware design guy and someone else will
>> (eventually) do thesoftware, hence he's trying to shorten his own
>> schedule since all he needs to do is verify he wired up the hardware
>> the right way and thesoftware guy can write the "real" code.