#277985 - 20/03/2006 16:08
MP3elf
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pooh-bah
Registered: 15/01/2002
Posts: 1866
Loc: Austin
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Has anyone seen this? http://mp3elf.net/index.phpIt looks kind of neat. Lately I've had the desire to play with PICs. This can program them, from what I understand. That's just a bonus, though.
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#277986 - 20/03/2006 17:17
Re: MP3elf
[Re: RobotCaleb]
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journeyman
Registered: 29/01/2001
Posts: 89
Loc: New Jersey, United States
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The St chip used by that thing is cooler than the one from ATMEL.
_________________________
The only difference between science fiction and reality is about 60 years.
100GB MK2 Green 080000171 + OEM tuner
v3.00a11 hijack v450 jEmpload v70
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#277987 - 21/03/2006 11:06
Re: MP3elf
[Re: RobotCaleb]
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addict
Registered: 24/07/2002
Posts: 618
Loc: South London
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Quote:
Lately I've had the desire to play with PICs. This can program them, from what I understand. That's just a bonus, though.
lol.
Can't think of anything worse to play with (PIC)! There's plenty of ARM7 based devices/prototype boards out there that will be a million times easier, less frustrating and more gratifying to play with!
Why hobbyists still persist with PIC's/AVR's is beyond me!
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#277988 - 21/03/2006 13:15
Re: MP3elf
[Re: sn00p]
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carpal tunnel
Registered: 24/12/2001
Posts: 5528
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Quote:
Can't think of anything worse to play with (PIC)! There's plenty of ARM7 based devices/prototype boards out there that will be a million times easier, less frustrating and more gratifying to play with!
Why hobbyists still persist with PIC's/AVR's is beyond me!
The PIC in this case is just for glue. Most of the brain is inside a Dalsemi/Maxim TINI Java stick thing.
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#277989 - 21/03/2006 13:47
Re: MP3elf
[Re: sn00p]
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carpal tunnel
Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
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My understanding is that PICs are cheap, at least compared to virtually everything else. No?
_________________________
Bitt Faulk
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#277990 - 21/03/2006 14:13
Re: MP3elf
[Re: wfaulk]
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addict
Registered: 24/07/2002
Posts: 618
Loc: South London
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For a hobbyist, no. For a product that ships thousands of units per month then maybe.
You can pick up a AT91SAM7S32 chip for about £3 in one off pricing. The AT91SAM7S256 can be had for about £8. They're significantly cheaper in even low volume multiples of 100.
Dev boards are cheap too, maybe ranging between $30 and $100 depending on what goodies the chip has on-board.
Given that your development tools are free (and the C compiler actually works - gcc) and that the jtag interface consists of a 30p buffer, the cost in terms of hardware & hair loss is significantly lower than using a PIC or AVR.
I have on my desk here at work a £12,000 emulator for a siemens processor, an AVR jtag-ice and a usb jtag interface for ARM and I can safely say that any project we do here from now either uses ARM7 or xscale. It's just not worth the time/effort/money trying to coax a 8 bit c-compiler to generate code that works, even for trivial applications.
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#277991 - 21/03/2006 14:42
Re: MP3elf
[Re: sn00p]
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carpal tunnel
Registered: 24/12/2001
Posts: 5528
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Forgot to say that you need the TINI eval module which is about $70 and Maxim for obvious reasons don't offer this part as a sample.
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#277992 - 21/03/2006 18:36
Re: MP3elf
[Re: sn00p]
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carpal tunnel
Registered: 17/01/2002
Posts: 3996
Loc: Manchester UK
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Long time no hear Adrian! I thought a discussion about microcontrollers might bring you back from the wilderness. I'm playing with a PICAXE at the moment which has it's good and bad points. But once I've got some spare time I'm going to give ARM7 a proper go.
_________________________
Cheers,
Andy M
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#277993 - 22/03/2006 05:13
Re: MP3elf
[Re: sn00p]
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carpal tunnel
Registered: 13/02/2002
Posts: 3212
Loc: Portland, OR
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Quote:
Quote:
Lately I've had the desire to play with PICs.
lol.
Can't think of anything worse to play with (PIC)! There's plenty of ARM7 based devices/prototype boards out there that will be a million times easier, less frustrating and more gratifying to play with!
Why hobbyists still persist with PIC's/AVR's is beyond me!
Quite probably because a) the market isn't as flooded with as many ARM7 resources, as there are PIC resources (I've been interested in PIC programming for the last couple years -- this is the first I've heard of using ARM7 as an alternative), and b) it seems overkill for a lot of very simple projects. Furthermore, as a hobbiest, I'd find the task of soldering an ARM7 onto a board (40 legs!) to be much more daunting than soldering a PIC onto a board.
So, supposing I were to take your advice, do you have any suggested resources that I should start with? (Including where I might find a low-cost programmer?)
My first project (which I've been putting off for *ages*) is to get something to convert my steering wheel control signals into a serial port stream to control the Empeg. How would using an ARM7 processor be simpler than using a PIC?
Cheers,
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#277994 - 22/03/2006 07:19
Re: MP3elf
[Re: canuckInOR]
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addict
Registered: 24/07/2002
Posts: 618
Loc: South London
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Quote:
Quite probably because a) the market isn't as flooded with as many ARM7 resources, as there are PIC resources (I've been interested in PIC programming for the last couple years -- this is the first I've heard of using ARM7 as an alternative), and b) it seems overkill for a lot of very simple projects. Furthermore, as a hobbiest, I'd find the task of soldering an ARM7 onto a board (40 legs!) to be much more daunting than soldering a PIC onto a board.
So, supposing I were to take your advice, do you have any suggested resources that I should start with? (Including where I might find a low-cost programmer?)
My first project (which I've been putting off for *ages*) is to get something to convert my steering wheel control signals into a serial port stream to control the Empeg. How would using an ARM7 processor be simpler than using a PIC?
Cheers,
I don't see it as overkill myself, time saver yes! Olimex make full populated ready to go breakout boards on standard dip pitch if that's what is worrying you.
Things will be easier on the ARM because:
1) You'll be able to program in 'C' and have confidence that the compiler is generating valid code. This is a massive time saver over using assembler on a pic or trying to get a pic compiler to generate non-junk.
2) They have plenty of RAM & FLASH and a good smattering of on board peripherals.
3) They're much of a muchness in terms of price for hobbyists if you compare to pics.
There's plenty of ARM7 based microcontrollers on the market now, which is the good news 
The philips lpc series, atmels AT91SAM7 series, analog devices ADuC series....etc. The even better news is that the philips & atmel families contain a lot of different devices in the range, so there's lots to choose from.
Here's some random urls:
lpc group
at91 sam group
at91 forum
and for your dev board/jtag requirements:
olimex
or their US reseller:
spark fun electronics
Now go forth and conquer (and leave the pics in the dustbin!)
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#277995 - 22/03/2006 08:26
Re: MP3elf
[Re: sn00p]
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carpal tunnel
Registered: 24/12/2001
Posts: 5528
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Quote:
1) You'll be able to program in 'C' and have confidence that the compiler is generating valid code. This is a massive time saver over using assembler on a pic or trying to get a pic compiler to generate non-junk.
I think you're been unnecessarily harsh on PIC C compilers. I've used several in the past and never had any problems with the generated code. Sometimes the compiler manufacturers extensions was a little odd in how they worked but it was still workable.
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#277996 - 23/03/2006 05:52
Re: MP3elf
[Re: sn00p]
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carpal tunnel
Registered: 13/02/2002
Posts: 3212
Loc: Portland, OR
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Quote:
I don't see it as overkill myself, time saver yes!
Well, as a budding hobbiest, I'm less interested in saving time -- it's a hobby, after all, it's supposed to suck up time.
Quote:
Olimex make full populated ready to go breakout boards on standard dip pitch if that's what is worrying you.
Well, my initial investigation of PICs leads me to believe that the standard MO is to develop your own custom circuit, and just add in whatever PIC you need. If I understand this, you're suggesting that I could just get something like the LPC-H2124, and I'm set to begin the programming part, as opposed to having to piece together a minimal circuit (aside from the leads to the steering wheel controls, to continue my previous example project).
Quote:
Things will be easier on the ARM because:
1) You'll be able to program in 'C' and have confidence that the compiler is generating valid code.
This would, indeed, make things simpler -- especially since I could then work on a linux machine. (The PIC resources for Linux are a little more scarce than for Windows.)
Quote:
2) They have plenty of RAM & FLASH and a good smattering of on board peripherals.
Perhaps I'm underestimating the amount of RAM and FLASH is necessary for simple projects. I'm not, after all, attempting to build an embedded web-server. And smatterings of peripherals, while handy when developing something where you want to give options, seems like a waste of space and resources, when I'm building something for a very specific purpose. (Of course, if you mean that I have the option of choosing boards with different peripherals (whether solo, or in groups), then I suppose I'd agree with that.
Quote:
3) They're much of a muchness in terms of price for hobbyists if you compare to pics.
Perhaps we're looking at different price lists, or I haven't done a sufficient investigation, but it appears that, while the initial outlay will be comparable (PIC + programmer + assorted bits vs. ARM board + jTag), the PIC route is cheaper once you start doing subsequent projects (depending on what the "assorted bits" are, I suppose, and in my case, I have a big drawer full of "assorted bits" that have been awaiting repurposing).
Quote:
Here's some random urls [...]
Ah, thanks. I'll browse through those.
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#277997 - 23/03/2006 06:32
Re: MP3elf
[Re: canuckInOR]
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addict
Registered: 24/07/2002
Posts: 618
Loc: South London
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Well, as a budding hobbiest, I'm less interested in saving time -- it's a hobby, after all, it's supposed to suck up time.
Yes, I but I'd rather suck up my time doing worthwhile development, not fighting with the processor/compiler/microchips awful datasheets.
Quote:
Well, my initial investigation of PICs leads me to believe that the standard MO is to develop your own custom circuit, and just add in whatever PIC you need. If I understand this, you're suggesting that I could just get something like the LPC-H2124, and I'm set to begin the programming part, as opposed to having to piece together a minimal circuit (aside from the leads to the steering wheel controls, to continue my previous example project).
Yes, very few external components are required, a couple of voltage regulators, decoupling caps and a crystal and you're good to go. They're fully integrated microcontrollers. Infact the SAM7 range is easier because they embedded the reset chip & 1.8V regulator inside the device, those ones just require the crystal & 3.3V!
Quote:
This would, indeed, make things simpler -- especially since I could then work on a linux machine. (The PIC resources for Linux are a little more scarce than for Windows.)
Yes, and it's free and well supported. Obvious advantage as well is that it's a pretty decent compiler too
Quote:
Perhaps I'm underestimating the amount of RAM and FLASH is necessary for simple projects. I'm not, after all, attempting to build an embedded web-server. And smatterings of peripherals, while handy when developing something where you want to give options, seems like a waste of space and resources, when I'm building something for a very specific purpose. (Of course, if you mean that I have the option of choosing boards with different peripherals (whether solo, or in groups), then I suppose I'd agree with that.
I try to run from RAM all the time, the advantage? Unlimited breakpoints. My target processor on the project I'm currently working on at work is a SAM7S128, but I use a SAM7S256, for the first month or so I was able to debug entirely out of RAM, which made life very easy and very quick.
While having oodles of RAM or FLASH might not seem necessary, when it's effectively coming for free (given the price differences between ARM7/PIC) then there is no reason to dismiss it purely because it's there! You also have to bear in mind that each instruction on the arm consumes 4 bytes (or 2 if you're running in thumb mode).
From memory the AT91SAM7S321 AT91SAM7S64 AT91SAM7S128 AT91SAM7S256 are all pin compatible, so you can make your mind up after the event on what chip and what resources you actually require.
Quote:
Perhaps we're looking at different price lists, or I haven't done a sufficient investigation, but it appears that, while the initial outlay will be comparable (PIC + programmer + assorted bits vs. ARM board + jTag), the PIC route is cheaper once you start doing subsequent projects (depending on what the "assorted bits" are, I suppose, and in my case, I have a big drawer full of "assorted bits" that have been awaiting repurposing).
You'll have to enlighten me as to what you mean by "assorted bits"?!
Have fun.
Adrian
Edit: Fixed the 5.5v typo tman spotted
Edited by sn00p (23/03/2006 07:19)
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#277998 - 23/03/2006 06:47
Re: MP3elf
[Re: sn00p]
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carpal tunnel
Registered: 24/12/2001
Posts: 5528
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Yes, very few external components are required, a couple of voltage regulators, decoupling caps and a crystal and you're good to go. They're fully integrated microcontrollers. Infact the SAM7 range is easier because they embedded the reset chip & 1.8V regulator inside the device, those ones just require the crystal & 5.5V!
A PIC is even easier. A ceramic resonator (or crystal + two caps) is pretty much it and some of them don't even require that if you're happy with the internal RC oscillator. You don't need odd voltages like 5.5V either.
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#277999 - 23/03/2006 07:17
Re: MP3elf
[Re: tman]
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addict
Registered: 24/07/2002
Posts: 618
Loc: South London
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Quote:
A PIC is even easier. A ceramic resonator (or crystal + two caps) is pretty much it and some of them don't even require that if you're happy with the internal RC oscillator. You don't need odd voltages like 5.5V either.
Yeah, but lets face it, putting a crystal, 2 caps and a voltage regulator is hardly demanding is it? Any design with a pic is going to have at least one voltage regulator!
It's a typo anyway, I meant 3.3V!
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