dsPIC ?!

[xenon_xplo]

i donno what is the difference between a High-End (18fxxx) PIC and a dsPIC (30fxxx) ?! plz some one help me out!

[ronsimpson]

I am not an expert but---
A PIC18Fxxxx is a better PIC16Fx with a multiply instruction, better memory, stack and more. Pic Basic Pro works with both.

A DSP is really good at math. (*,+,-,/, and shift) Some DSP can do several math functions in one clock. PBP will not work with a PIC30Fxxx. I wish!!!!!

[mister_e]

the best solution is to go on the Microchip website and compare both, side by side. DsPIC are really great but reaaaaaaaaallllllly different animal than other series 18F or lower.

No coincidence why there's not much compiler who support them. 'Till now Microchip C30, Hi-Tech C, and Mikro Elektronika if my memory is good. I heard that some other alreday work on this.... be patient...

I use them in some audio dsp stuff.

[skimask]

the best solution is to go on the Microchip website and compare both, side by side. DsPIC are really great but reaaaaaaaaallllllly different animal than other series 18F or lower.

No coincidence why there's not much compiler who support them. 'Till now Microchip C30, Hi-Tech C, and Mikro Elektronika if my memory is good. I heard that some other alreday work on this.... be patient...

I use them in some audio dsp stuff.

You're using them already? I was thinking about buying the MikroBasic for dsPICs and building one of those huge audio spectrum analyzers using their FFT code. How good is that Microchip code for Audio DSP (well, compared to the garbage they put out for the PIC18Fxxx series a few years ago)...
JDG

[mister_e]

Well, the Microchip audio library AS IS is really poor IMHO.. BUT NO DSP sounds good anyways. If you work a little bit in the existing library... you may have a decent sound. The external hardware is still the key to improve it.

Some will say DSP is the way to go and it offer the best solution... but it's often the same kind of people who will say that MP3 sound is also good Audio is an analog thing, so the best way to treat it, is always in analog... but it's not going to fit in the same room and the pricing will never be the same.

You'll have to work few days/weeks/months with those DsPIC before getting comfortable with. I don't use them often but i do appreciate their power.

I can't vouch on any MikroElektronika compiler, i don't use them and i don't have them. And 'till now, none of my customer asked me to develop on MikroE compiler. Maybe one day. I heard they're better than before so far.

I love their development board... for the price and what you get, NONE on the market beat them.

18F send garbage because they have their limitation. They're not dedicated for that. 24 series could do better.

Most of the time, you find better match with existing Dsp solution + simple microcontroller (12F, 16F or else) for about the same price, and save development time. At least Ti and ST do some nice one.

if you want to do a simple audio spectrum, analyser... you should have a look at TDA7416... half job is done and you get a free eq with

[ronsimpson]

Micro vs DSP
A micro is built to look at a key—blink a LED- send “hello” out the serial port.
A DSP is built to look at audio or video and do 100s of millions of math operations/second. I have worked on projects where we looked at a pixel of video plus the nearest 10 pixels (times 3; red, green & blue) ran all 30 values through a formula 30,000,000 times a second. The little dsPIC cannot run that fast. A DSP can do micro-type jobs like blink a LED but it is a wast.

MATH: Let’s say we have an 8 bit micro. The largest number it can easily think of is 11111111 binary or 255 decimal. 255+1=0 + carry. So:254+1=255+1=0+1=1+1=2+1=3
Numbers role over from largest to smallest or from smallest to largest.

In typical DSP math there is “saturation”. So:254+1=255+1=255+1=255+1=255-1=254-1=253 In audio if the signal gets too large it should saturate or clip not role over!

The Mikro.com compilers look good. The Basic, C and Pascal compilers have the same look and feel. (good) The PIC, 8051, RISK and DSP compilers have the same look and feel. (mostly good) I think the DSP version treats the DSP like a micro to get the same feel. The little dsPIC should be able to do 40 bit adds, substation and shifts with saturation in one instruction and 17 bit multiplies with saturation. By looking at the manual and I feel the DSP-mikroBASIC compiler only uses 16 bit ‘role over’ math. There is no real DSP functions. I do not see a way of easily making an audio graphic-equalizer out of a dsPIC using the DSP-mikroBASIC compiler. A DSP doing a micro’s job will be fast, but if it is limited to doing a micro’s job by the mikro compiler. I just could not find FFT code maybe I misted it.