Re: uC Slection for a learner project

On May 4, 6:21 am, Neil <NeilKu...@xxxxxxxxxxxxxxxx> wrote:
linnix wrote:
On May 3, 11:41 am, Hans-Bernhard Bröker <HBBroe...@xxxxxxxxxxx>
wrote:
AC Me wrote:
I would like to construct a data logger. This data logger may be
located in areas remote from power and human kind. It will read 1-Wire
interfaced weather instruments at an interval of 2 seconds and store
the weather data over an extended period of time, such as a year.
That's not going to be cheap.  You're talking about several tens of
megabytes of data there!

The
weather data acquired should be stored with the date and time.
That's at least 3 bytes for the time-stamp alone, and you would be
storing 15 million samples per year.  That makes 45 MB before you've
stored the first bit of actual payload data.

A 45MB compact flash is less than $1, if you can still find it so
small.
A couple of Gs are reasonable in price too.

 Writing flash is in itself quite an energy-consuming operation.

But you can buffer the data and only write every few minutes.

Sure it is possible.  But as a beginners project?  What is you power
budget? How many what hours is the protect?  Many small MCUs can do the
job PIC, AVR, MP430.  None can talk to a USB Stick without another chip.
  This should kill you power budget.  None have a 1-wire interface.  I
am not sure any thing does.
What do you know, any software or hardware?  ASM, C, Basic?- Hide quoted text -

- Show quoted text -

Thanks for the response. I would like the power consumption to be as
low as possible.
The time taken to bring this to completion is not important to me. The
primary purpose is
so that I can learn. I have looked at lots and lots of uCs and just
became even more
bewildered than I am normally :). That's why I asked you guys - I
though I might get a list
of a few uCs that come close and from which I could choose the most
appropriate device.

For instance, the PIC18F97J60 has 10BT ethernet, but no USB, no 1-Wire
and no LCD
drive capability. The PIC18F85J90 has an LCD drive capability, but no
ethernet or USB.
The PIC 18F13K50 has USB 2.0, but no ethernet or LCD. The MSP430CG4616
has LCD
but no ethernet, no USB, etc. The Atmel AT32UC3A0512 has 10/100
ethernet and USB but
no LCd and is knda high power (in my view although Atmel claim low
power). The Maxim
MAXQ2000 has a RTC, LCD, 1-Wire but no USB or ethernet.

From other posts to this forum, I note that a company called FTDI
manufacture a chip
(well chips) to add a USB port to a uC using SPI, if I recall
correctly.

So perhaps the MAXIM part might be the most suitable, if I add the
FTDI part?
That would still leave the matter of communicating with a PC for
configuration
purposes. Any ideas?

From my original post, I did (a long time ago) use machine code,
assembler and BASIC.
I taught myself C in the early '90s, but havn't had much experience
using this since then.

Mike
.

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