DSP parts with free dev software/cheap dev tools?

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View
Hi - I'm looking at doing some DSP work (specifically, I'm working on
an AHARS system).

I've never worked with a DSP - but I understand them to essentially be
a microcontroller with especially strong math abilities. Thus this
seems like a perfect solution to my needs.

Problem is - it seems most all DSPs require expensive dev software and
hardware. I'm coming from the ARM and AVR world where software is free
and programmers are inexpensive. Being a student - this transition is a
bit unpleasant.

Are there any inexpensive routs into the DSP world? I'm looking for a C
compiler and some way of programming a board of my own design (I don't
plan on buying any dev boards).

-Mike


Re: DSP parts with free dev software/cheap dev tools?


Quoted text here. Click to load it

Watch out -- you can get away with that thinking to some degree, but it
may bite you.

Most DSPs are designed for two purposes: number-crunching and fast I/O.
They are not designed for ease of programming, or to have loads of
peripherals. These days, many of them do, but at heart, most DSPs are a
different world. You should think of them first as a peripheral or
coprocessor, and second as a micro, and then only if you have a good C
compiler.

In fact, it used to be that you were very lucky indeed to get a C
compiler on a DSP. It also used to be rare for DSPs to deal gracefully
with 8-bit quantities. Both of these things are becoming more common as
people demand to program everything in C, but they're not universal --
particularly the latter. Expect weirdness like non-8-bit chars and
40-bit floats.

Also, a DSP doesn't automatically bring higher performance. It will
usually get you much farther than would a micro at the same speed, but
you may have to work to get there. A C compiler for a DSP may get you
through a good first pass, but after that, you'll often need to tweak
by hand to get maximum performance. It can be well worth the effort,
but effort is required.

Quoted text here. Click to load it

I know the feeling well.

Quoted text here. Click to load it

That may be tough. Others may know more, but I don't know of anything
inexpensive that fits the bill.

Would an FPGA + micro fit? FPGA tools are often cheap or free.

Good luck -- and hopefully somebody can give more concrete advice. (In
fact, I'll be interested myself to see whether people come up with
anything.)

--mpa


Re: DSP parts with free dev software/cheap dev tools?

The original poster hasn't said anything, but I thought I'd jump in,
because I'm interested too.

So far, everybody's posted about free / cheap compilers, demo boards,
etc. The missing element is the *programmer*.

For example, I designed a small sub-US$100 board, which you can easily
order now, and which makes a fairly nice DSP development kit ..

.. except for one thing: you need a US$1200 programmer to debug with
it, and a license for a certain proprietary compiler to compile code
for it at all. (It's not sold as a development board, so no questions
please. :) ) If the programmer weren't $1200.00, it would be a much
better proposition, but the development system and software are
prohibitive.

I think the answer may turn out to be ARM -- not because the chip is
fastest, but because the programming hardware is plentiful and cheap,
and the compiler is free. It seems that DSPs are still Big Iron.

--mpa


Re: DSP parts with free dev software/cheap dev tools?

Quoted text here. Click to load it

Look at http://www.bdti.com/faq/3.htm
There is a fair bit of info available.
The free tools seem to based on fairly old versions of gcc.
It might be that ARM using gcc 4 might be faster with DSP
type tasks than the DSPs using older versions of gcc.

Regards
  Anton Erasmus

Re: DSP parts with free dev software/cheap dev tools?

Quoted text here. Click to load it
It is my understanding that the DsPIC from Microchip has a gcc compiler
available.  Check.

ARMs are pretty quick, and as mentioned elsewhere to really get the
speed advantage of a DSP you have to sign up to some assembly
programming, with some serious thought given to how the processor
expects you to program it.

--

Tim Wescott
Wescott Design Services
We've slightly trimmed the long signature. Click to see the full one.
Re: DSP parts with free dev software/cheap dev tools?

Quoted text here. Click to load it

Or use a library written by somebody who knew what they were
doing.   And if you think compilers are expensive...

Quoted text here. Click to load it

--
Grant Edwards                   grante             Yow!  They
                                  at               collapsed... like nuns
We've slightly trimmed the long signature. Click to see the full one.
Re: DSP parts with free dev software/cheap dev tools?
Quoted text here. Click to load it

I understand that Microchip provides a free C compiler. DsPICs max out
at 40MIPS which is a little slow for my tastes, especially since they
are only 16b and most of the work I'll be doing will be on floats or
doubles.

Quoted text here. Click to load it

Most ARMs don't have FPUs, however. I am aware of a couple that do, but
that is a very uncommon feature among ARMs. Still, it is something I am
considering.

-Mike


Re: DSP parts with free dev software/cheap dev tools?

Quoted text here. Click to load it

Airborne Heading-Attitude Reference System?

Quoted text here. Click to load it

I've been using the ADSP-21xx series DSP processors for 15 years and
more.  There was an older assembler, linker and so on that you may be
able to get for free from Analog Devices support folks.  The
particular toolset is their version 5.1 tools.  It came on three
floppies and I've had their tools folks (one of them, anyway) send me
a complete set of them (after losing my one.)  When getting that copy,
the tool guy wasn't caring at all whether or not I owned a license to
other products they do sell and I'm pretty sure Analog Devices doesn't
really care anymore about that old toolset.  I have them still and if
this is something you'd like I can call over to them and see if I can
get permission of one sort or another to give you a copy.  (The ZIP is
about 4.3Meg.)

I also have the 37 page release notes for it.  This includes the
following description:

    • The software may require up to 13.5 MB of hard disk storage—see
      page 3 for storage requirements.
    • For all software except the C compiler, the minimum system
      configuration is a ’286 based PC with 2 MB extended RAM (DOS 3.0
      or higher), a hard disk, 640K of memory, a color video card and
      an EGA or VGA monitor, and a high density floppy disk drive.
    • The C compiler requires a ’386 or ’486 based PC.
    • The recommended system configuration is a ’386 or ’486 based PC
      with 4 MB extended RAM, DOS 3.0 or higher, a hard disk, 640K of
      memory, a color video card and an EGA or VGA monitor, a high
      density floppy disk drive and a mouse.

    What’s New In This Release?

    • The release of ADSP-2181 and ADSP-21msp59 software development
      tools. This release includes modifications to the System
      Builder, Assembler, Linker, PROM Splitter, Compiler, C Runtime
      Library, and two new Simulators. The details of ADSP-2181
      support are covered in section 4.1, “New Features of Release 5.1
      (ADSP-2181 Support)”.

That would be 'free.'  However, their cheap EZ-ICE board isn't around
anymore, I believe.  They have something more expensive and fancy out
there, now.  Not sure how much you could pull together for development
but I thought I'd offer a thought, just in case.  I think you'd need
to work to pull together a workable situation, but this toolset could
get you pretty far if the processor is otherwise workable.

Jon

Re: DSP parts with free dev software/cheap dev tools?

Quoted text here. Click to load it

We sell a small credit card sized DSP board (DSP-8300) that uses an ADSP-
2186M and an AC-97 codec. We supply it with the 5.1 Tools. These tools
were never copyrighted and were largely GNU based which is why they are
available for free.

We also have SHARC based boards that include a built in ADI debugger.
These boards are supported with Visual DSP and will work with a free KIT
license.

Check out our web site if you are interested.





--
Al Clark
Danville Signal Processing, Inc.
We've slightly trimmed the long signature. Click to see the full one.
Re: DSP parts with free dev software/cheap dev tools?

Quoted text here. Click to load it

Ah.  I see.  I only used the assembler tool.  It doesn't seem to be
GAS based, though.

Quoted text here. Click to load it

I will.  What a KIT license is, I suppose I need to read it to find
out -- unless I can assume that it means I can use them for a kit you
sell.

Jon

Re: DSP parts with free dev software/cheap dev tools?
Quoted text here. Click to load it
ADSP-
Quoted text here. Click to load it
KIT

Visual DSP is the Analog Devices development tool. There are three
licenses available.

1.    Full Version. You buy this once and then upgrades are free.
2.    Test Drive, same as full license for 90 days, then stops working
3.    Kit License - sames as full license for 90 days, then restricts
program size to about 1/4 of the DSP memory. Does not support simulator
or external ICE. Requires EZ-KIT style debugger which is available on ADI
EZ-KITs and some of our dspstak 21369 boards. - Free. You can create
bootable images that can be loaded on our production boards or another
target.         




--
Al Clark
Danville Signal Processing, Inc.
We've slightly trimmed the long signature. Click to see the full one.
Re: DSP parts with free dev software/cheap dev tools?

Quoted text here. Click to load it

Ah.  I have two full version licenses, so no need in my case.  But I'm
interested in details for others, who may be curious and wish to play
as a hobbyist.

Thanks,
Jon

Re: DSP parts with free dev software/cheap dev tools?

Quoted text here. Click to load it

Exactly. My plan is to have 3 axes of magnetometer, 3 axes of gyro, 3
axes of accelerometer, and a gps. The gyro and accelerometer will be
sampled at probably 2KHz. GPS will be coming in at 4Hz, not sure about
magnetometer (haven't chosen what kind to use just yet). I'll be mixing
the gyro and accelerometer data with a kalman filter. GPS and
magnetometer will be used to further fix the gyro and accelerometer
data.

Quoted text here. Click to load it

I would think that something that aged would be substantially slower
than modern software. I really would like to maximize my usage of
whatever chip I end up with.

-Mike


Re: DSP parts with free dev software/cheap dev tools?
Quoted text here. Click to load it

Is this for a product or could it be open source ?

I would be interested in what you are doing if your open to it.

donald

Re: DSP parts with free dev software/cheap dev tools?

Quoted text here. Click to load it

I'm currently thinking I'll open source it. Its end application is for
a robot I designed that has been completely open sourced. (though I
haven't publicly posted the URL for the website about it, as the
website is not quite finished). Then again, I think it might be
marketable - so I might sell the hardware while keeping the software
(and hardware design) free.

You might be interested in this open sourced kalman filter
implementation for a 6DOF IMU (3 accelerometer, 3 gyro):
http://www.dev6.com /

-Mike


Re: DSP parts with free dev software/cheap dev tools?
Quoted text here. Click to load it

  You have not mentioned the precisions or calculation rates you need,
but one suggestion would be to take a std 32 bit C microcontroller, and
code using that.
  We recently did a fixed point scaled problem, using the Zilog ZNEO.
This has MUL/DIV opcodes with extended precision (32*32 -> 64, and
64/32 -> 32), and it also has a free compiler, and simulator.
  IIRC we did a 64 bit ratio and ten 32 bit divides/stores in appx 19us,
using assembler (because what we needed was more easily done in assembler).

  It has 32 bit registers, and IIRC, the C has 32 bit float type, so
would be a free 'reference point' - just grab the ZDS II from Zilog's
web site.

  If that's not enough for your final app, another possible pathway,
would be to use the Lattice Mico32 Soft CPU, with HW assist as needed.

-jg



Re: DSP parts with free dev software/cheap dev tools?

Quoted text here. Click to load it


I can't speak for the C compiler.  Never used it.  And frankly, I
doubt it does much with this DSP's capability of packing up to 3
instructions into a single word or in handling register-passing
optimizations on it.  But as your post suggests you are willing to
consider, writing in assembly also isn't unusual in the case of DSPs.
However, I'm familiar with numeric methods and perfectly willing to
work out the details of writing optimized equations in assembler on a
DSP.  You may not be and you have to be the judge here of what fits
your need.  I was only suggesting an alternative without really
knowing what skills you have or much about what you are trying to do.

Best of luck,
Jon

Re: DSP parts with free dev software/cheap dev tools?
Quoted text here. Click to load it
... snip ...
Quoted text here. Click to load it

On the contrary, it probably isn't wasting time on frivolous guis,
and is probably faster than whatever is 'modern'.

--
Chuck F (cbfalconer at maineline dot net)
   Available for consulting/temporary embedded and systems.
We've slightly trimmed the long signature. Click to see the full one.
Re: DSP parts with free dev software/cheap dev tools?
Is there any TI or ADSP simulator  available for free?

Quoted text here. Click to load it
wasting time on frivolous guis,
Quoted text here. Click to load it


Re: DSP parts with free dev software/cheap dev tools?

Quoted text here. Click to load it

The ADSP simulator is; the 5.1 version, anyway.

Jon

Site Timeline