Community: Message List

Re: FIR filter: how to use memory?

support@line6.com — Mon, 25 Feb 2013 18:29:50 GMT

If you are still working on this...

For linear phase FIR filters (typical application), the impulse response (coefficients) must be

symmetric: h[n] = h[N-n-1] e.g. h[0] = h[1023], h[1] = h[1022], etc.

anti-symmetric: h[n] = -h[N-n-1]

For a 1024 tap filter, you really only need to store 512 coefficients. With proper addressing (modulo pointers), you can do 2 MAC operations with the same coefficient, looping 512 times. When the # of coefficients is odd, you need to handle the middle coefficient as a special case, outside the filter loop at the end.

With proper design, an IIR (recursive) filter can be used to approximate a long FIR filter, maybe only requiring 3 or 4 coefficients.

Or the DSP could be used to compute the coefficients dynamically at boot time storing them in X or Y data memory.

Then you would not need to download them in the code image.

Cheers,

Mike

Re: Is Stereo Dock still being made?

support@line6.com — Tue, 19 Feb 2013 20:15:56 GMT

If you have good mechanical skills and soldering skills, a mono-dock can be converted to a stereo dock.

Involves drilling 2 holes on each side of a mono-dock case (after disassembling it), removing 2 (or 4?) zero-ohm jumper resistors and installing 2 Neutric 1/4" jacks.

I did it with my mono-dock about 1 year ago. Drilling the holes is the hardest part - maybe a hacksaw and round file could be used as well.

Or for a little more money (less effort) - buy a used stereo dock from musicgoround, Guitar Center, Sam Ash, etc.

Cheers,

Mike

Re: Status of this product

support@line6.com — Mon, 16 Jan 2012 01:30:12 GMT

Yes, my mistake. You are correct. Hopefully someone from Line6 can correct this problem.

Re: Why does the ToneCore Development Kit only ship within the U.S?

support@line6.com — Sat, 14 Jan 2012 23:53:45 GMT

If you are able to read the Tonecore schematics (free) it is possible to add USB to any Tonecore dock and make it function like a developer's kit.

Only three wires USB+, USB- and Ground are needed. Hack any USB cable, drill a small hole into the side of a tonecore dock (pedal), solder these three wires and you have a developer dock.

Then you just need to obtain the programmable modules from Line 6 and start writing your effect in DSP code, load and try it out.

Cheers,

Mike

Re: Status of this product

support@line6.com — Sat, 14 Jan 2012 23:45:58 GMT

It now shows 22 blank modules in stock, when stock = 1, then they are out of stock. Not sure about phase out of this product.

The programmable (blank) module plugs into the pedal (dock). The mono and stereo dock show stock = 1 (out of stock).

If you are good at reading schematics (free to download here) you can wire in a USB connector (3 wires: USB+, USB- and GND) to any Line 6 tonecore pedal (in the midboard circuit) and have a developer kit at lower cost. Just drill a small hole in the side of the pedal and pass the USB cable with connector out.

If interested, I have pictures of the process - let me know and I can send what I have off-list.

You still need to buy the $35 programmable modules from Line 6, but only need to modify one base pedal (dock) to add the USB to program them.

Cheers,
Mike

Re: Tonecore DSP P:ROM library functions?

support@line6.com — Mon, 01 Nov 2010 17:04:42 GMT

Many thanks for this info. I have submitted a request to Freescale for more details (as you did).

What they provide is just the API (function calls/parameters)?

Or do they provide source code listing of the ROM?

I would think with source code, I may be able to learn and reuse some audio processing routines - after converting them from block processing to per sample.

For a small block size, < 8 samples, perhaps the time delay would not be that much of a problem with block processing?

Maybe the processing loops inside the ROM can be called directly, with the desired block size?

It will be interesting to find out..

Cheers,

Mike

Tonecore DSP P:ROM library functions?

support@line6.com — Sat, 30 Oct 2010 20:43:07 GMT

Hi,

I am able to read out non-zero values from the DSP56364 8K words of Program ROM memory starting at $FF1000.

Example:

Address Data

FF1000 0AF080

FF1001 FF13FF

FF1002 FF1015

FF1003 FF101A

FF1004 FF101F

FF1005 FF1024

FF1006 00000C

... ...

Are there functions/tables in this Program ROM that Tonecore developers could use? e.g. FIR filters, FFT routines, sine/log/exp lookup tables, etc?

Is there an API (application programmers interface) or similar document that describes what is contained in the DSP P-ROM memory?

I could read out each value and perform inverse assembly, but was hoping that some documentation was available - maybe from Freescale?

Many thanks for any help here.

Regards,

Mike

Re: Availability of ToneCore Programmable Modules

support@line6.com — Wed, 06 Oct 2010 15:48:21 GMT

What is the planned production 'lifetime' for the ToneCore Programmable Modules and ToneDock pedals?

Will Line 6 make them as long as there is demand for them? Or will Line 6 stop producing them in the future (say 4 or 5 years from now)?

My reason for asking is that many music retailers no longer are offering the ToneCore pedals and modules (e.g. Constrictor/UberMetal/EchoPark).

I see that Freescale DSP56364 is not recommended for new designs - so it may become unavailable as well.

Thanks,

Mike

Re: RE: ToneCore module only avalaible in US? How to buy Tone Core modules in Europe?

support@line6.com — Sat, 02 Oct 2010 17:44:14 GMT

The tonecore modules are also available on eBay

Or search on Google in US for online seller of Echo Park module.

Re: RE: Fixing broken pedal

support@line6.com — Tue, 05 Oct 2010 16:50:59 GMT

Portugal and France (in Gent, Belgium) have service centers

Americo Nogueira, Lda

Servicing: Electronics, Guitars

R. Norton de Matos, 712
4405-671 Gulpilhares
Vila Nova de Gaia, California+351 22 730 0650 (phone)
+351 22 730 0659 (fax)
amenog@esoterica.pt

Fuzz It - Centre de Réparation Line 6 (Francophone)

Hugo Van Der Goesstraat 17A
Gent
9000
+32 938 30580 (phone)
support@line6.be