I a half year or so I will probably want to use an ARM microcontroller.
I remember somebody here mentionned a user forum or such...?
(search engines does not have experience to tell what sites are good quality, nor find good discussion lists ;) )
I am interested in good ARM references; manufacturers portfolios, european suppliers, starter kits, tools, tips, user groups.
Tool range is between hobby and expert. I must not waste time, but programming is only a small part of what i do, resources are needed most other places...
I will probably only usea few k program space and program interrupts in assembly and main program in some high level language. Preferrably tool suite on Linux (I use Mandriva in the new computer)
Mechanically it will need to be hand solderable for low production, QFP is OK, while BGA is not... Electrically I need a (slow) 14bit differential A/D with 100mV range, does there exist any such on- chip?
> I a half year or so I will probably want to use an ARM
> microcontroller.
James: [ARM] ?
> I am interested in good ARM references; manufacturers
> portfolios, european suppliers, starter kits, tools, tips,
> user groups.
Olimex has ARM boards, I resell them (as many others do, but some don't
mention that they sell Olimex stuff).
> I will probably only usea few k program space and program
> interrupts in assembly and main program in some high level
> language. Preferrably tool suite on Linux (I use Mandriva in
> the new computer)
I use only Win stuff. We use PSPad as IDE, GCC compiler, Insight
debugger, in-school build 2106 boards with wiggler-hardware. Up to now
only assembler and C, I am preparing for C++.
> Mechanically it will need to be hand solderable for low
> production, QFP is OK, while BGA is not... Electrically I
> need a (slow) 14bit differential A/D with 100mV range, does
> there exist any such on- chip?
IIRC the A/Ds on the Philips chips are 10 bit. Isn't 14 bit a bit too
much for being on the same die as the processor?
Wouter van Ooijen
-- -------------------------------------------
Van Ooijen Technische Informatica: http://www.voti.nl
consultancy, development, PICmicro products
docent Hogeschool van Utrecht: http://www.voti.nl/hvu
Morgan Olsson wrote:
> Electrically I need a (slow) 14bit
> differential A/D with 100mV range, does there exist any such on- chip?
I don't know much about ARM, but I doubt you'll find that sort of A/D on any
microcontroller. Note that you're asking for 6uV resolution. Lots of
digital circuitry on the same chip makes that pretty much impossible. You
will also have to pay attention to power and ground in a way that is not
necessary for a digital processor. 14 bit power and ground will be easier
at the substantially lower current draw of a separate A/D chip.
Microchip has various A/Ds that might do what you want. None of them (or
probably from any other manufacturer) will have a native 100mV full scale.
This means you either need an external gain amp (may need the buffer
anyway), or use an A/D with more resolution and "waste" the extra.
Microchip has some sigma-delta converters that do over 20 bits that might be
useful in the latter role. High precision sigma-deltas can be useful when
you only need a few 10s of Hz speed. The extra resolution lets you cover up
a lot of sins in the software.
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>I a half year or so I will probably want to use an ARM microcontroller.
>
>I remember somebody here mentionned a user forum or such...?
>(search engines does not have experience to tell what sites are good
>quality, nor find good discussion lists ;) )
>
>I am interested in good ARM references; manufacturers portfolios, european
>suppliers, starter kits, tools, tips, user groups.
>
>Tool range is between hobby and expert. I must not waste time, but
>programming is only a small part of what i do, resources are needed most
>other places...
>
>I will probably only usea few k program space and program interrupts in
>assembly and main program in some high level language. Preferrably tool
>suite on Linux (I use Mandriva in the new computer)
>
>Mechanically it will need to be hand solderable for low production, QFP is
>OK, while BGA is not... Electrically I need a (slow) 14bit differential
>A/D with 100mV range, does there exist any such on- chip?
>
>/Morgan
Hi, Morgan:-
AD has preliminary info on their devices using the ubiquitous ARM7TDMI core--
perhaps with availability within your time frame. Unfortunately, the first
set of them will only have crummy resolution (12-bit) ADC and no PGA.
You should at least consider Keil for the tool chain- as you probably know,
they were recently acquired by ARM.
Take a look at Silicon Labs C8051F06x. They have two 16-bit
ADCs and are quite fast. There is also a US$29 demo board
for the C8051F064 which let you download the program and
debug the MCU with USB connection. It is very impressive.
Keil C51 compiler is one of the best MCU compiler. The
free open source SDCC also works nicely with the MCU.
Regards,
Xiaofan
Analog Peripherals
- Two 16-Bit SAR ADCs
* 16-bit resolution
* ±0.75 LSB INL, guaranteed no missing codes
* Programmable throughput up to 1 Msps
* Operate as two single-ended or one differential converter
* Direct memory access; data stored in RAM without
software overhead
...
On-Chip JTAG Debug & Boundary Scan
...
High Speed 8051 µC Core
- Pipelined instruction architecture; executes 70% of
instruction set in 1 or 2 system clocks
- Up to 25 MIPS throughput with 25 MHz clock
- Flexible Interrupt sources
...
Clock Sources
- Internal calibrated precision oscillator: 24.5 MHz
- External oscillator: Crystal, RC, C, or clock
...
Supply Voltage .......................... 2.7 to 3.6 V
- Multiple power saving sleep and shutdown modes
100-Pin and 64-Pin TQFP Packages Available
Temperature Range: -40 to +85 °C
Chen Xiao Fan 01:50 2005-11-08:
>If this is not good enough for the ADC, take a look at
>C8051F35x: 8ch x24bit ADCs, 1ksps.
Impressive.
But as people pointed out, wonder how much noise there will be from the microcontroller. One method is to stop it during converison, but i can not do that in this app. I will have a look, theese new 80xx really are interesting. But I would like to play with an ARM...
For the A/D i could use external LTC24xx. Locating the A/D at the sensor and have SPI comm might be a better solution anyway.
>
> Thank you for your answers so far
>
> No hint of ARM forum/discussion list?
>
> Chen Xiao Fan 01:50 2005-11-08:
> >If this is not good enough for the ADC, take a look at
> >C8051F35x: 8ch x24bit ADCs, 1ksps.
>
> Impressive.
>
> But as people pointed out, wonder how much noise there will be from the
> microcontroller. One method is to stop it during converison, but i can not
> do that in this app. I will have a look, theese new 80xx really are
> interesting. But I would like to play with an ARM...
>
> For the A/D i could use external LTC24xx. Locating the A/D at the sensor
> and have SPI comm might be a better solution anyway.
>
> /Morgan
> --
> Morgan Olsson, Kivik, Sweden
>
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