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Discussion Groups | 68HC12 | c tutorial needed

Join our technical discussions about Freescale Microcontrollers: M68HC12. (Freescale Semiconductor is a Subsidiary of Motorola).

c tutorial needed - Ed Taylor - Mar 7 17:41:00 2003

hi:

i'm going to start programming in c, however the last time i dabbled in it was ten plus years ago in dos and i only scratched the surface. i've got 25 plus years in assembler and also write applications in xbasic (database). could someone recommend a good book to get me going?

thanks in advance

regards,

ed

[Non-text portions of this message have been removed]


______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!


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Re: c tutorial needed - Bob White - Mar 7 18:04:00 2003

I like "Pointers on C" by Reek (Addison Wesley).
Bob White

----- Original Message -----
From: "Ed Taylor" <>
To: <>
Sent: Friday, March 07, 2003 2:41 PM
Subject: [68HC12] c tutorial needed hi:

i'm going to start programming in c, however the last time i dabbled in it
was ten plus years ago in dos and i only scratched the surface. i've got 25
plus years in assembler and also write applications in xbasic (database).
could someone recommend a good book to get me going?

thanks in advance

regards,

ed

[Non-text portions of this message have been removed]
--------------------------------------------------------
To unsubscribe from this group, send an email to: To learn more about Motorola Microcontrollers, please visit
http://www.motorola.com/mcu




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Re: c tutorial needed - Ed Taylor - Mar 7 18:21:00 2003

hi bob:

thanks for your reply!

i'll check it out.

regards,

ed
----- Original Message -----
From: "Bob White" <>
To: <>
Sent: Friday, March 07, 2003 4:04 PM
Subject: Re: [68HC12] c tutorial needed > I like "Pointers on C" by Reek (Addison Wesley).
> Bob White
>
> ----- Original Message -----
> From: "Ed Taylor" <>
> To: <>
> Sent: Friday, March 07, 2003 2:41 PM
> Subject: [68HC12] c tutorial needed > hi:
>
> i'm going to start programming in c, however the last time i dabbled in it
> was ten plus years ago in dos and i only scratched the surface. i've got
25
> plus years in assembler and also write applications in xbasic (database).
> could someone recommend a good book to get me going?
>
> thanks in advance
>
> regards,
>
> ed
>
> [Non-text portions of this message have been removed] >
> --------------------------------------------------------
> To unsubscribe from this group, send an email to: > To learn more about Motorola Microcontrollers, please visit
> http://www.motorola.com/mcu >
>
> --------------------------------------------------------
> To unsubscribe from this group, send an email to: > To learn more about Motorola Microcontrollers, please visit
> http://www.motorola.com/mcu






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Question for Gordon Doughman - Paul Johnson - Mar 8 11:15:00 2003

I checked out your book on amazon, but there was very little information
there. BTW, the link to your book on motorola's url
(http://e-www.motorola.com/webapp/sps/site/taxonomy.jsp?nodeId=0162468636863
7) appears to be bad. It looks like RTC books no longer carries your book.

Amazon does seem to have it, with a 13 day leadtime.

My question is: does your book cover iic programming? All of the examples
in motorola literature are for interrupt programming, which is
inappropriate/unnecessary for the chip I wish to talk to (a clock/calendar
chip which will be referenced only occasionally).

I have already placed an order for you book with Amazon because I'm sure it
will have some valuable tidbits anyway.

Best regards,

Paul Johnson
Lynx Robotics
8125 Lankershim Blvd.
North Hollywood, CA 91605
Voice: (818) 252-7890
FAX: (818) 252-7892




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Quadrature Inputs - Paul Johnson - Mar 8 11:28:00 2003

I'm surprised, given the number of embedded applications involving motor
control or data capture, that almost no micros out there support quadrature
input. On our products, we use Xilinx FPGA's that provide 8 sets of
quadrature input and handle all the accumulation, etc.

However, on small footprint boards, with a simple task, it would be very
desirable to lose the Xilinx and just read quadrature directly. Even just
one pair of quadrature inputs would be fine.

Has anyone out there solved this problem?

Thanks,

Paul Johnson
Lynx Robotics
8125 Lankershim Blvd.
North Hollywood, CA 91605
Voice: (818) 252-7890
FAX: (818) 252-7892




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RE: c tutorial needed - Kellogg Dave - Mar 8 12:26:00 2003

You might also look at "C: How to Program" by Deitel & Deitel (ISBN
0130895725). While I have no direct experience with this book, I found a
similar book in the series "C++: How to Program" to be very good.

I really like Ken Reek's book, but it might be too aggressive for just
beginning. FYI: Its back cover says "Designed for professionals and
advanced students...". That said, get it anyway. It will help you advance
faster.

"C: A Reference Manual, 5th ed." by Harbison & Steele (ISBN 013089592X) is a
very good reference, too. 607-656-2597 -----Original Message-----
From: Ed Taylor [mailto:]
Sent: Friday, March 07, 2003 6:22 PM
To:
Subject: Re: [68HC12] c tutorial needed hi bob:

thanks for your reply!

i'll check it out.

regards,

ed
----- Original Message -----
From: "Bob White" <>
To: <>
Sent: Friday, March 07, 2003 4:04 PM
Subject: Re: [68HC12] c tutorial needed > I like "Pointers on C" by Reek (Addison Wesley).
> Bob White
>
> ----- Original Message -----
> From: "Ed Taylor" <>
> To: <>
> Sent: Friday, March 07, 2003 2:41 PM
> Subject: [68HC12] c tutorial needed > hi:
>
> i'm going to start programming in c, however the last time i dabbled
> in it was ten plus years ago in dos and i only scratched the surface.
> i've got
25
> plus years in assembler and also write applications in xbasic
> (database). could someone recommend a good book to get me going?
>
> thanks in advance
>
> regards,
>
> ed
>
> [Non-text portions of this message have been removed] >
> --------------------------------------------------------
> To unsubscribe from this group, send an email to: > To learn more about Motorola Microcontrollers, please visit
> http://www.motorola.com/mcu >
>
> --------------------------------------------------------
> To unsubscribe from this group, send an email to: > To learn more about Motorola Microcontrollers, please visit
> http://www.motorola.com/mcu

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Re: Quadrature Inputs - Oliver Betz - Mar 8 13:12:00 2003

"Paul Johnson" <> wrote:

>I'm surprised, given the number of embedded applications involving motor
>control or data capture, that almost no micros out there support quadrature
>input. On our products, we use Xilinx FPGA's that provide 8 sets of

Ack, that's bad.

[...]

>Has anyone out there solved this problem?

Do you know the LS7183 from www.lsicsi.com ? It seems you could count
the up and down pulses with HC12 pulse counters.

I already used a small, cheap PIC for this task, these days I would
use a HC08.

Oliver
--
Oliver Betz, Muenchen


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Re: Quadrature Inputs - Jiri Gutman - Mar 8 15:12:00 2003


Hi Paul,

yes, the quadrature input is important and rare. But there is one optimal
solution - go to see the Motorola Hybrid solution - DSP56F800 family.

http://e-www.motorola.com/webapp/sps/site/taxonomy.jsp?nodeId=01M95961783629
2
or go direct to DSP56F803

http://e-www.motorola.com/webapp/sps/site/prod_summary.jsp?code=DSP56F803&no
deId=0127956292

Many information and tools on the Motor Control you can find at
http://e-www.motorola.com/webapp/sps/site/homepage.jsp?nodeId=03nQXG

Regards
Jiri > ----- Original Message -----
> From: "Paul Johnson" <>
> To: <>
> Sent: Saturday, March 08, 2003 5:28 PM
> Subject: [68HC12] Quadrature Inputs > > I'm surprised, given the number of embedded applications involving motor
> > control or data capture, that almost no micros out there support
> quadrature
> > input. On our products, we use Xilinx FPGA's that provide 8 sets of
> > quadrature input and handle all the accumulation, etc.
> >
> > However, on small footprint boards, with a simple task, it would be very
> > desirable to lose the Xilinx and just read quadrature directly. Even
just
> > one pair of quadrature inputs would be fine.
> >
> > Has anyone out there solved this problem?
> >
> > Thanks,
> >
> > Paul Johnson
> > Lynx Robotics
> > 8125 Lankershim Blvd.
> > North Hollywood, CA 91605
> > Voice: (818) 252-7890
> > FAX: (818) 252-7892
> >
> >
> >
> > --------------------------------------------------------
> > To unsubscribe from this group, send an email to:
> >
> >
> > To learn more about Motorola Microcontrollers, please visit
> > http://www.motorola.com/mcu
> >
> >
> >
> >
> >
>



______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!


(You need to be a member of 68hc12 -- send a blank email to 68hc12-subscribe@yahoogroups.com )

Re: Quadrature Inputs - Robert Smith - Mar 8 15:17:00 2003

Don't forget the MC68332 provides quadrature inputs via the TPU. But I am
sure since the original poster is looking for 'HC12, small footprint
soutions, even the '332 may be too big a stretch for him but not as severe
as going to DSP chips.

Also, keep in mind that various vendors make encoder chips. HP and Gailel
come to mind. Check also Nat Semi.

Bob Smith

--- Avoid computer viruses, Practice safe hex ---

-- Specializing in small, cost effective
embedded control systems --

http://www.smithmachineworks.com/embedprod.html Robert L. (Bob) Smith
Smith Machine Works, Inc.
9900 Lumlay Road
Richmond, VA 23236 804/745-1065
----- Original Message -----
From: "Jiri Gutman" <>
To: <>
Sent: Saturday, March 08, 2003 3:12 PM
Subject: Re: [68HC12] Quadrature Inputs >
> Hi Paul,
>
> yes, the quadrature input is important and rare. But there is one optimal
> solution - go to see the Motorola Hybrid solution - DSP56F800 family. http://e-www.motorola.com/webapp/sps/site/taxonomy.jsp?nodeId=01M95961783629
> 2
> or go direct to DSP56F803 http://e-www.motorola.com/webapp/sps/site/prod_summary.jsp?code=DSP56F803&no
> deId=0127956292
>
> Many information and tools on the Motor Control you can find at
> http://e-www.motorola.com/webapp/sps/site/homepage.jsp?nodeId=03nQXG
>
> Regards
> Jiri > > ----- Original Message -----
> > From: "Paul Johnson" <>
> > To: <>
> > Sent: Saturday, March 08, 2003 5:28 PM
> > Subject: [68HC12] Quadrature Inputs
> >
> >
> > > I'm surprised, given the number of embedded applications involving
motor
> > > control or data capture, that almost no micros out there support
> > quadrature
> > > input. On our products, we use Xilinx FPGA's that provide 8 sets of
> > > quadrature input and handle all the accumulation, etc.
> > >
> > > However, on small footprint boards, with a simple task, it would be
very
> > > desirable to lose the Xilinx and just read quadrature directly. Even
> just
> > > one pair of quadrature inputs would be fine.
> > >
> > > Has anyone out there solved this problem?
> > >
> > > Thanks,
> > >
> > > Paul Johnson
> > > Lynx Robotics
> > > 8125 Lankershim Blvd.
> > > North Hollywood, CA 91605
> > > Voice: (818) 252-7890
> > > FAX: (818) 252-7892
> > >
> > >
> > >
> > > --------------------------------------------------------
> > > To unsubscribe from this group, send an email to:
> > >
> > >
> > > To learn more about Motorola Microcontrollers, please visit
> > > http://www.motorola.com/mcu
> > >
> > >
> > >
> > >
> > >
> > >
> >
> --------------------------------------------------------
> To unsubscribe from this group, send an email to: > To learn more about Motorola Microcontrollers, please visit
> http://www.motorola.com/mcu



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RE: c tutorial needed - Vien Nguyen - Mar 8 19:23:00 2003

Hi,

Sorry I can't remember any tittle to recommend right now, but have a look at
this website and see if it helps you in finding what you really need.
http://www.accu.org/

Regards,

Vien Nguyen.





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RE: Quadrature Inputs - Paul Johnson - Mar 8 20:47:00 2003

> >I'm surprised, given the number of embedded applications involving motor
> >control or data capture, that almost no micros out there support
> quadrature
> >input. On our products, we use Xilinx FPGA's that provide 8 sets of
>
> Ack, that's bad.

I'm sorry, Oliver, I don't know what you mean. Do you mean that it's bad
that we're using Xilinx's or that there are no micros out there with
quadrature, or something different altogether?

> >Has anyone out there solved this problem?
>
> Do you know the LS7183 from www.lsicsi.com ? It seems you could count
> the up and down pulses with HC12 pulse counters.

I didn't, and thanks for the reference. However the reason for quadrature
is that it's so much more noise immune than clock and direction or dual
clock. Still, on a small board, close to the micro, this might not be a
problem.

> I already used a small, cheap PIC for this task, these days I would
> use a HC08.

Yes, precisely, I am looking to do it with a PIC. I was hoping there was a
solution out there so that I would not have to reinvent the wheel. Ideally,
I would like a parallel interface to off-board accumulators.

Regards,

Paul



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RE: Quadrature Inputs - Paul Johnson - Mar 8 20:49:00 2003

Hi Jiri,

I did find these chips, but they are quite a bit larger and more expensive
than this little board requires. Most of the resources would be wasted as
well. They do look like great chips for larger designs.

You would think that some of the high-end PIC's, with their focus on motor
control, would have addressed this issue, but apparently not.

Regards,

Paul

> -----Original Message-----
> From: Jiri Gutman [mailto:]
> Sent: Saturday, March 08, 2003 12:13 PM
> To:
> Subject: Re: [68HC12] Quadrature Inputs >
> Hi Paul,
>
> yes, the quadrature input is important and rare. But there is one optimal
> solution - go to see the Motorola Hybrid solution - DSP56F800 family.
>
> http://e-www.motorola.com/webapp/sps/site/taxonomy.jsp?nodeId=01M9
> 5961783629
> 2
> or go direct to DSP56F803
>
> http://e-www.motorola.com/webapp/sps/site/prod_summary.jsp?code=DS
> P56F803&no
> deId=0127956292
>
> Many information and tools on the Motor Control you can find at
> http://e-www.motorola.com/webapp/sps/site/homepage.jsp?nodeId=03nQXG
>
> Regards
> Jiri > > ----- Original Message -----
> > From: "Paul Johnson" <>
> > To: <>
> > Sent: Saturday, March 08, 2003 5:28 PM
> > Subject: [68HC12] Quadrature Inputs
> >
> >
> > > I'm surprised, given the number of embedded applications
> involving motor
> > > control or data capture, that almost no micros out there support
> > quadrature
> > > input. On our products, we use Xilinx FPGA's that provide 8 sets of
> > > quadrature input and handle all the accumulation, etc.
> > >
> > > However, on small footprint boards, with a simple task, it
> would be very
> > > desirable to lose the Xilinx and just read quadrature directly. Even
> just
> > > one pair of quadrature inputs would be fine.
> > >
> > > Has anyone out there solved this problem?
> > >
> > > Thanks,
> > >
> > > Paul Johnson
> > > Lynx Robotics
> > > 8125 Lankershim Blvd.
> > > North Hollywood, CA 91605
> > > Voice: (818) 252-7890
> > > FAX: (818) 252-7892
> > >
> > >
> > >
> > > --------------------------------------------------------
> > > To unsubscribe from this group, send an email to:
> > >
> > >
> > > To learn more about Motorola Microcontrollers, please visit
> > > http://www.motorola.com/mcu
> > >
> > >
> > >
> > >
> > >
> > >
> >
> --------------------------------------------------------
> To unsubscribe from this group, send an email to: > To learn more about Motorola Microcontrollers, please visit
> http://www.motorola.com/mcu



______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!


(You need to be a member of 68hc12 -- send a blank email to 68hc12-subscribe@yahoogroups.com )

Re: Quadrature Inputs - Author Unknown - Mar 8 23:04:00 2003

In a message dated 3/8/03 8:52:38 PM Eastern Standard Time,
writes:

> I'm surprised, given the number of embedded applications
> involving motor
> control or data capture, that almost no micros out there support
> quadrature
> input. On our products, we use Xilinx FPGA's that provide 8 sets of
> quadrature input and handle all the accumulation, etc.
> However, on small footprint boards, with a simple task, it
> would be very
> desirable to lose the Xilinx and just read quadrature directly. Even
> just
> one pair of quadrature inputs would be fine.
> Has anyone out there solved this problem?

Just hook one of the encoder lines to an input with edge triggered interrupt,
arm for falling edge interrupt (for instance), read other encoder line in
handler, inc on hi, dec on lo.
[Non-text portions of this message have been removed]



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Re: Quadrature Inputs - Oliver Betz - Mar 9 8:15:00 2003

"Paul Johnson" <> wrote:

[...]

>I'm sorry, Oliver, I don't know what you mean. Do you mean that it's bad

I meant that it's bad that uCs seldom have quadrature inputs.

[...]

>Yes, precisely, I am looking to do it with a PIC. I was hoping there was a
>solution out there so that I would not have to reinvent the wheel. Ideally,
>I would like a parallel interface to off-board accumulators.

It's pretty simple:

In a loop: Concatenate the actual two bit encoder information with the
saved two bits of the last round. From these 4 Bits you get 16
combinations, forward, backward, no change and illegal (each four
times).

Use a jump table to increment/decrement the counter (accumulator) or
signal an error.

Use some kind of handshake to the host if you output parallel data:
either a strobe signal triggered by the host, or a "data illegal" bit.

With a 20MHz PIC, I got 4,5us cycle time IIRC.

Oliver
--
Oliver Betz, Muenchen


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Re: c tutorial needed - Robert Smith - Mar 9 8:20:00 2003

Starting from a similar background, I have never used anything but the
original reference:

"The C Progrming Language", by K & R, Prentice Hall.

It is written in a friendly, near-tutorial style that is clear to read and
contains many examples.

The First Edition covering the original language is ISBN 0-13-110163-3. It
is paper-bound and I find it easier to flip through and read.

The Second Edition covering the ANSI hack to C is ISBN 0-13-110370-9. Hard
bound, but more up to date in re the ANSI standards. Not quite as easy to
read as the First Edition.

But, be sure that you have the compiler reference manual for the compiler
you intend to use. It will fill in many "implementation dependent" issues
and is essential for understanding your compiler.

The transition from assembler to C is pretty easy. Just "think assembler"
and send a _lot_ of time looking at the compiler generated code.

"C u later", Bob Smith --- Avoid computer viruses, Practice safe hex ---

-- Specializing in small, cost effective
embedded control systems --

http://www.smithmachineworks.com/embedprod.html Robert L. (Bob) Smith
Smith Machine Works, Inc.
9900 Lumlay Road
Richmond, VA 23236 804/745-1065
----- Original Message -----
From: "Ed Taylor" <>
To: <>
Sent: Friday, March 07, 2003 5:41 PM
Subject: [68HC12] c tutorial needed > hi:
>
> i'm going to start programming in c, however the last time i dabbled in it
was ten plus years ago in dos and i only scratched the surface. i've got 25
plus years in assembler and also write applications in xbasic (database).
could someone recommend a good book to get me going?
>
> thanks in advance
>
> regards,
>
> ed
>
> [Non-text portions of this message have been removed] >
> --------------------------------------------------------
> To unsubscribe from this group, send an email to: > To learn more about Motorola Microcontrollers, please visit
> http://www.motorola.com/mcu



(You need to be a member of 68hc12 -- send a blank email to 68hc12-subscribe@yahoogroups.com )

Re: c tutorial needed - Michael Pont - Mar 9 11:08:00 2003

Personally, I've never found K&R to be the best introduction to C.

I'd start with something like Schildt "Teach Yourself C".

Michael.

----- Original Message -----

> Starting from a similar background, I have never used anything but the
> original reference:
>
> "The C Progrming Language", by K & R, Prentice Hall.





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RE: Quadrature Inputs - Paul Johnson - Mar 9 11:16:00 2003

> It's pretty simple:
>
> In a loop: Concatenate the actual two bit encoder information with the
> saved two bits of the last round. From these 4 Bits you get 16
> combinations, forward, backward, no change and illegal (each four
> times).
>
> Use a jump table to increment/decrement the counter (accumulator) or
> signal an error.
>
> Use some kind of handshake to the host if you output parallel data:
> either a strobe signal triggered by the host, or a "data illegal" bit.
>
> With a 20MHz PIC, I got 4,5us cycle time IIRC.

It sounds like this is a polling approach. I was thinking of doing
something similar to what Bob suggested, but attaching Quad-A to an
interrupt which triggers on any transition, then checking the value of the
other line in the ISR. I suppose that if the encoder was sitting right on a
line, however, this might swamp the interrupt input, but I have not commonly
seen this with encoders. With low interrupt latency, I would think this
would be pretty reliable, no?

Paul


______________________________
controlSUITE™ software. Comprehensive. Intuitive. Optimized.
Real-world software for real-time control. Details Here!


(You need to be a member of 68hc12 -- send a blank email to 68hc12-subscribe@yahoogroups.com )

Re: c tutorial needed - Andrew Lohmann's New Email Server - Mar 10 4:00:00 2003

Also look at "Programming Microcontrollers in C" by Ted Van Sickle, I think its been reprinted and it's about HC11/16, and a few others. Motorola reference TB328 on my old copy (ISBN 1-878707-14-0).

It has a mistake in setting interrupt vectors, but it takes you through the basics and gets you going.

IAR's user guide's are good as they explain all the C keywords, but I don't recommend the compiler. Andrew Lohmann AIIE
Design Engineer

Bellingham + Stanley Ltd.
Longfield Road, Tunbridge Wells, Kent, TN2 3EY, England.
Tel: +44 (0) 1892 500400
Fax: +44 (0) 1892 543115
Website: www.bs-ltd.com ----- Original Message -----
From: Michael Pont
To:
Sent: Sunday, March 09, 2003 4:08 PM
Subject: Re: [68HC12] c tutorial needed Personally, I've never found K&R to be the best introduction to C.

I'd start with something like Schildt "Teach Yourself C".

Michael.

----- Original Message -----

> Starting from a similar background, I have never used anything but the
> original reference:
>
> "The C Progrming Language", by K & R, Prentice Hall.

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Re: Quadrature Inputs - John Smith - Mar 10 5:24:00 2003

Hi,

Some years back i did a winch controle wire out and speed for a ship trawl
warps.
I used a 8051 then and did it as follows:

Used a D-type latch 74HCT74 with PRE/CLR connected to Vcc. The one phase
input connected to "D" input and the Q connected to a port pin (the /Q not
used).

The other phase goes to the Clock pin on the D type latch and at the same
time to a interrupt line on the processor.

Both phases should be buffered with hysterieses , barrier diode, caps etc.

IT WORKS AS FOLLOW:......78>))

The the one phase feeding into D and the other into the clock input of the
74HCT74 we obtain the phase leading or lagging so we can figure out what
direction the shaft turns. The Q output will indicate the direction "0" one
direction "1" other direction.

The one phase feeding straight into the CPU has to functions. First, it is
used to measure time intervals for measuring shaft speed. Second, it is used
as a pulse counter to measure length of wire. So we end up with 3 neat
variables, speed wire out and direction!!

Now just for the interrest of it. Do not place your sensors on the wire
drum!!! Place your sensors on a roler that has a consistant diameter to the
cable spooling.............

Frank van der Merwe(the info is free....)

----- Original Message -----
From: <>
To: <>
Sent: Saturday, March 08, 2003 8:04 PM
Subject: Re: [68HC12] Quadrature Inputs > In a message dated 3/8/03 8:52:38 PM Eastern Standard Time,
> writes:
>
> > I'm surprised, given the number of embedded applications
> > involving motor
> > control or data capture, that almost no micros out there support
> > quadrature
> > input. On our products, we use Xilinx FPGA's that provide 8 sets of
> > quadrature input and handle all the accumulation, etc.
> > However, on small footprint boards, with a simple task, it
> > would be very
> > desirable to lose the Xilinx and just read quadrature directly. Even
> > just
> > one pair of quadrature inputs would be fine.
> > Has anyone out there solved this problem?
>
> Just hook one of the encoder lines to an input with edge triggered
interrupt,
> arm for falling edge interrupt (for instance), read other encoder line in
> handler, inc on hi, dec on lo. >
> [Non-text portions of this message have been removed] >
> --------------------------------------------------------
> To unsubscribe from this group, send an email to: > To learn more about Motorola Microcontrollers, please visit
> http://www.motorola.com/mcu



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RE: c tutorial needed - Allen, Nick - Mar 10 10:35:00 2003

I'm surprised that no one has recommended this for online information:

Developing Embedded Software in C Using ICC11/ICC12/Hiware
Jonathan W. Valvano
http://www.ece.utexas.edu/~valvano/embed/toc1.htm

It's a good concise tool
Nick
> -----Original Message-----
> From: Ed Taylor [mailto:]
> Sent: Friday, March 07, 2003 5:41 PM
> To:
> Subject: [68HC12] c tutorial needed > hi:
>
> i'm going to start programming in c, however the last time i
> dabbled in it was ten plus years ago in dos and i only
> scratched the surface. i've got 25 plus years in assembler
> and also write applications in xbasic (database). could
> someone recommend a good book to get me going?
>
> thanks in advance
>
> regards,
>
> ed
>
> [Non-text portions of this message have been removed] > ------------------------ Yahoo! Groups Sponsor
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RE: c tutorial needed - Kellogg Dave - Mar 10 10:41:00 2003

Paul --
Sorry about that.

Pointers on C, by Kenneth A Reek. ISBN 0673999866 607-656-2597 -----Original Message-----
From: Paul Johnson [mailto:]
Sent: Saturday, March 08, 2003 8:41 PM
To:
Subject: RE: [68HC12] c tutorial needed I couldn't find any reference to Ken Reek on Amazon. Do you have a title?

Thanks,

Paul

> -----Original Message-----
> From: Kellogg Dave [mailto:]
> Sent: Saturday, March 08, 2003 9:26 AM
> To: '
> Subject: RE: [68HC12] c tutorial needed > You might also look at "C: How to Program" by Deitel & Deitel (ISBN
> 0130895725). While I have no direct experience with this book, I
> found a similar book in the series "C++: How to Program" to be very
> good.
>
> I really like Ken Reek's book, but it might be too aggressive for just
> beginning. FYI: Its back cover says "Designed for professionals and
> advanced students...". That said, get it anyway. It will help you
> advance faster.
>
> "C: A Reference Manual, 5th ed." by Harbison & Steele (ISBN
> 013089592X) is a
> very good reference, too. > 607-656-2597 > -----Original Message-----
> From: Ed Taylor [mailto:]
> Sent: Friday, March 07, 2003 6:22 PM
> To:
> Subject: Re: [68HC12] c tutorial needed > hi bob:
>
> thanks for your reply!
>
> i'll check it out.
>
> regards,
>
> ed
> ----- Original Message -----
> From: "Bob White" <>
> To: <>
> Sent: Friday, March 07, 2003 4:04 PM
> Subject: Re: [68HC12] c tutorial needed > > I like "Pointers on C" by Reek (Addison Wesley).
> > Bob White
> >
> > ----- Original Message -----
> > From: "Ed Taylor" <>
> > To: <>
> > Sent: Friday, March 07, 2003 2:41 PM
> > Subject: [68HC12] c tutorial needed
> >
> >
> > hi:
> >
> > i'm going to start programming in c, however the last time i dabbled
> > in it was ten plus years ago in dos and i only scratched the
> > surface. i've got
> 25
> > plus years in assembler and also write applications in xbasic
> > (database). could someone recommend a good book to get me going?
> >
> > thanks in advance
> >
> > regards,
> >
> > ed
> >
> > [Non-text portions of this message have been removed]
> >
> >
> >
> > --------------------------------------------------------
> > To unsubscribe from this group, send an email to:
> >
> >
> > To learn more about Motorola Microcontrollers, please visit
> > http://www.motorola.com/mcu
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > --------------------------------------------------------
> > To unsubscribe from this group, send an email to:
> >
> >
> > To learn more about Motorola Microcontrollers, please visit
> > http://www.motorola.com/mcu
> >
> >
> >
> >
> >
> >
>
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>
> --------------------------------------------------------
> To unsubscribe from this group, send an email to: > To learn more about Motorola Microcontrollers, please visit
> http://www.motorola.com/mcu >
> --------------------------------------------------------
> To unsubscribe from this group, send an email to: > To learn more about Motorola Microcontrollers, please visit
> http://www.motorola.com/mcu

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Re: Quadrature Inputs - gary_olmstead - Mar 21 7:31:00 2003

--- In , "Paul Johnson" <paul@l...> wrote:
> > It's pretty simple:
> >
> It sounds like this is a polling approach. I was thinking of doing
> something similar to what Bob suggested, but attaching Quad-A to an
> interrupt which triggers on any transition, then checking the value
of the
> other line in the ISR. I suppose that if the encoder was sitting
right on a
> line, however, this might swamp the interrupt input, but I have not
commonly
> seen this with encoders. With low interrupt latency, I would think
this
> would be pretty reliable, no?
>
> Paul

Reliable yes. I have done it exactly that way several times. You
don't need PICs or D-flops or anything, at least if you have two
spare inputs. If you don't need maximum resolution, set one as an
input capture on a fixed edge (either one), and every time you get an
interrupt, examine the level of the _other_ input. It works in
either direction, and the time between interrupts gives you the
speed. You can get much more resolution by interrupting on both
edges of both inputs, but that gets tricky, so only do it if you need
the resolution.

I live down the road from you, so if you need a higher level of
assistance, let me know, I can come by.

Gary Olmstead
Toucan Technology
Ventura CA

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