Best micro for teaching purposes?

The atmel "butterfly" board could be a good starting point.

http://www.atmel.com/dyn/products/tools_card.asp?tool_id31%46

Mike Silva wrote:


I just realized how ambiguous my question is.  I've been in the
embedded business for about 25 years, at least half of that on 8-bit
devices, and I'm asking now in regard to an introductory course which I
may end up teaching.  I am interested right now particularly in
settling on an architecture, but I'll also need to find a good student
training board (which may involve revisiting the choice of micro).

@i39g2000cwa.googlegroups.com:



We have a course centered on the PIC line.

CCS has some very nice boards designed to support student labs, and the
student compiler comes fairly cheap.  My only knock of the boards are that
they don't use a chip carrier, so you need to be careful of the student
blowing up the uP.

CCS also has some very nice inexpensive proto boards that are a tick up
from the student version, but not really a budget breaker.

I'd suggest contacting them, letting them know you're interested in
supporting a course, and see what kind of package they can put together for
you.  They might even comp you a system for evaluation.

Whatever you, don't choose the PIC, it is a horrid device, unrepresentative
of the majority of micros your students will find in their careers and it
uses completely non standard terminology.

Ian

Ian Bell wrote:


Now this is getting interesting.  I think I can safely say that I have
used all of the "top" dozen or so 8-bit families -except- the PIC.  I
have avoided it because of various unflattering things I have read
about it.  So, while I am predisposed to agree with your assessment, I
would have to do some research to convert my bias into an informed
opinion.

No problem. I have used microcontroller for over 20 years. When I retired I
wanted to select a micro for personal projects and the PIC seemed to be
popular amongst hobbyists. So I investigated it thoroughly and was very
disappointed. Pity really.

Ian

My biggest issue with the PIC micros is the constant bank switching you
need to do if writing in assembler.  I've been playing a lot with the
Zilog Encore series, the development boards are reasonable and a full,
not code limited, C compiler is included.

Tom

I used a Z8 in a development some years back (CO2 monitor). Nice little
micros as I recall.

Ian

as said before an unbiased group here. I love the pic range some people seem
to
unable to read and have problems because its is different. But then I like
different and I don't code in C as you can get tighter code for the device
you are using.
I have seen many boards with a massive micro to do a simple task often in
the name of
reusable code.

if I were to teach I think C would be more use to a greater number of
students. The micro
choice would reflect that.

David

I am not biased, I looked very closely at using the PIC when I retired after
over 20 years designing microcomputer products and the PIC was just so odd.
And there are even Linux based tools for it too but even that did not
persuade me.



I'm with you on C. Never used it on an microcontroller yet.

< I have seen many boards with a massive micro to do a simple task often in


You forgot to mention portability ;-)



Seems to be the way things are going.

Ian

I use the PIC processor for teaching (undergraduate UK degree course).
Currently we use the 16F877 in a home-brew target baord.  Actually the
choice of processor is not too important as there are many that are pin
compatible.  We are considering changing to the 18F422 (or is it 442??) but
as we program in C the difference as viewed by the end user are slight.

We currently use the ICD1 with MPLAB V5.4 (later versions do not support the
ICD1) with the Hitecc PICC lite compiler (limited code size, but never been
a problem in classroom exercises).  One of our criteria was to use free
software if possible so that students can have their own copy.  MPLAB +
evaluation PICC lite fits these criteria.  A couple of copies of the full
version might be useful for more advanced project work.

We have just designed an ICD2 clone which we will use next academic year
with the later version of MPLAB. If we use the 18F422 we will need to choose
a different compiler.  Microchip do a free student version although I have
not evaluated it.

Our target board has a 4 digit multiplexed 7-segment LED display (excellent
for programing exercises, albeit a little outdated), 6 pushbutton switches
and 6 LEDs (arranged as 2 sets of traffic lights), a temperature sensor, LDR
and potentiometer as analog inputs.

However, there are many commercially available boards which, if I were
starting again, I might consider using instead.

Recommendations given in this group for teaching kit rarely suggest using an
ICD, possibly due to cost.  However, I cannot over state how useful I find
it to teach sensible development and debugging techniques, not possible if
all one uses is a PIC programmer.  If you use an ICD clone (such as
available from www.olimex.com) or build your own the cost is not excessive.

Look at Atmel AVR family.... good development/tutorial  board, JTAG devices
now available too.

folks

Hi Mike,

This is a question I also have thought about on & off for a little
while.

I use and like the Z8 Encore devices. But you need to be a little more
specific about what you need. I use the Z8 in an embedded systems class
for computer science students. You might want something else for
computer engineering or electrical engineering .

Here is why I like the Z8 Encore:

- Consistency between parts in family
- 64K flash, 4K RAM (on the upper end)
- Lots of on-chip peripherals (UARTs, I2C, SPI, Analog, 3-4 Timers)
- Easy to use
- Low cost development kits ($40 from digikey, futurlec).
- The biggest benefit (for me) is the IDE, the compiler is not crippled,
  it does not have a limited code size like some of the other
  microcontrollers free tools have.
- The IDE is free from Zilog and that includes C compiler, assembler,
  emulator and debugger (this is a BIG deal for me since I teach a night
  class which has no in class lab time, so the students can work on labs
  and projects on thier own time and there are no licensing problems
  with the tools, some of the tools I have seen for other processors are
  only 30 day licenses or are licensed to a single user/computer).
- Im using an old developers board which has a lot of stuff on board
  (2 serial ports, 144 LED martix, temperature sensor, header pins, etc)
  so the students don't need to mess with hooking in things too early
  in the class (remember, its a CS class). Unfortunately its not
  available anymore.

Some things I don't like about the Z8 Encore

- Compiler is a buggy
- No 3rd party compiler or assembler
- No JTAG (uses a simple one wire program/debug pin).
- Zilog could go belly up at anytime (and has come close several times
  in recent history).
- Application notes are terrible (buggy, or just plain bad).
- The data and address buses are not available on the IO pins.
- The on-chip peripheral support API is very poor (or not at all
  for some of the peripherals).
- Zilog is not a bad company but they are far from the best as far as
  quality, tech support and product support (databooks, app notes, etc).

If I had to pick another microcontroller I would think about these
(but I can't say right now that any of them 100% meet my needs). They
all look like good micros but I have not evaluated the tools yet.

- TI MSP430 or MSP470 (ARM7)
- Renesas M16C
- Maxim MAXQ or the Maxim/Dallas 80C400
- Atmel AVR
 

Hi Mike,

your choice will also depend on what you want to teach.

Here are some topics that come into my mind (my recommendations are only
based on the few uCs I know):

1) proccessor core
- AVR as a nice, straightforward core
- MSP430 is not as orthogonal, but designed with some amount of thinking

2) peripherals
- MSP430 has very nice internal peripherals

3) debugging
- JTAG is a very nice thing to have, but you can also debug old-style with
some LEDs ;-)

4) C-programming
- it is better to have some RAM for this...

5) squeezing the last bit out of the uC
- PIC seems to be unbeatable here ;-)))

6) interfacing sensors
- parts with ADC should be available in every family

7) interfacing external peripherals/memory
- some AVR parts have an external bus

--------------

And now some remarks on the uCs I have used

1) IMHO the reason for PIC being so popular is that it was the first uC with
Flash that was widely available. A clear pro is the vast amount of websites
dedicated to PICs. Besides that I can't think of much reasons to use these
in the 21st century. (Of course, they are cheap if you think about selling
something in great quantities).

2) AVR is very nice for personal use. Some parts have an external bus, which
is a good thing for greater projects. The amount of webpages on AVR is also
very big.
One thing I really don't like about the architecture is the use of fuse
bytes for configuring the oscillator. It's quite easy to set the device to
external osc, and you then need an external clock source to reprogram the
fuses ;-)
Also Atmel had a habit of discontinuing parts, but this may have changed as
the chips have matured.

With WinAVR there seems to be a good free software package that contains
everthing you need to develop.

3) Though MSP430 is a 16-bit architecture, I think it fits in here.
The architecture is designed with much thought. It is really fun to think of
uses for the timer-blocks...
An MSP would not run with 5V. This still scares people away, but I believe
we are at a point where using 3.3V only is no problem.
A problem for your application could be that they are not available as
through-hole and the sockets for TQFP are quite expansive.

There is a gcc-port available, but I don't know anything about its quality.

------------------

All that said, I would go with AVR, although I like MSP430 better.

/Jan-Hinnerk

Mike, I think that is a good choice. Also there is another one 9s12 which is
similar to HC11 and HC12 but more efficient and cheap. There are diffterent
evaluation boards and many books available.

That is a good choice. Easy to work with and you can use C programming also.
You can try 9s12, they are close to HC11 and HC12 but smaller and more
efficient plus it is cheaper too.