Asking for some PIC guidance
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Asking for some PIC guidance

 
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Guest






Posted: Mon Dec 12, 2005 1:35 am    Post subject: Asking for some PIC guidance Reply with quote

Hi there,

Apologies in advance if I didn't pick quite the right newsgroups to
post this in. I'm a total newbie to PIC use in robotics or motor
actuation, however I'm very familiar with embedded development concepts
(Assembly on embedded M68K FPGA, etc). I'm very familiar with
languages like C, Assembly, and Basic. What I want to do is drive a
12V DC motor based on several sensor inputs. When sensor inputs
change, I want the motor to spin in the opposite direction from last
time. The logic would be very simple, and I need the hardware to be as
compact as possible. We're talking drive currents in the neighborhood
of several amps. Where do you suggest I start (buying hardware,
learning resources, etc)? Thanks in advance for all suggestions!

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Spehro Pefhany
Guest





Posted: Mon Dec 12, 2005 1:35 am    Post subject: Re: Asking for some PIC guidance Reply with quote

Budget? For hobby or is this a commercial project?


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
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Guest






Posted: Mon Dec 12, 2005 8:37 am    Post subject: Re: Asking for some PIC guidance Reply with quote

Spehro,

Right now it's a pet project of mine that has the potential of turning
into a commercial venture if successful. The budget is couple hundred
dollars at most. Any ideas?

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Spehro Pefhany
Guest





Posted: Mon Dec 12, 2005 8:59 am    Post subject: Re: Asking for some PIC guidance Reply with quote

On 11 Dec 2005 18:37:07 -0800, the renowned slavinger@yahoo.com wrote:

Quote:
Spehro,

Right now it's a pet project of mine that has the potential of turning
into a commercial venture if successful. The budget is couple hundred
dollars at most. Any ideas?

That's not quite enough for your parts and the tools I'm personally
familiar with, so I'll leave it to others for specific advice.

I suggest you stick with assembly language and the free MPLAB
development software, which you can download from Microchip. These are
simple devices, your application is not complex, and your learning
curve will probably be less if you don't have to wrestle with another
level of software.

You may wish to join the piclist. For hardware design, Art of
Electronics is getting a bit long in the tooth (2nd edition) but
should be more than sufficient for your purposes. You'll probably end
up using at least one power MOSFET for the drive (maybe 4 in an
H-bridge or maybe one and a reversing relay).

Your project sounds very simple, and any of the 14-bit instruction
PICs should be able to handle it. Maybe a 16F88 or something like that
if there are enough pins.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com
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Guest






Posted: Mon Dec 12, 2005 9:05 am    Post subject: Re: Asking for some PIC guidance Reply with quote

slavinger@yahoo.com wrote:
Quote:
Hi there,

Apologies in advance if I didn't pick quite the right newsgroups to
post this in. I'm a total newbie to PIC use in robotics or motor
actuation, however I'm very familiar with embedded development concepts
(Assembly on embedded M68K FPGA, etc). I'm very familiar with
languages like C, Assembly, and Basic. What I want to do is drive a
12V DC motor based on several sensor inputs. When sensor inputs
change, I want the motor to spin in the opposite direction from last
time. The logic would be very simple, and I need the hardware to be as
compact as possible. We're talking drive currents in the neighborhood
of several amps. Where do you suggest I start (buying hardware,
learning resources, etc)? Thanks in advance for all suggestions!

There are application notes on the microchip site for driving small dc
motors.
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Jim Granville
Guest





Posted: Mon Dec 12, 2005 9:35 am    Post subject: Re: Asking for some PIC guidance Reply with quote

slavinger@yahoo.com wrote:
Quote:
Spehro,

Right now it's a pet project of mine that has the potential of turning
into a commercial venture if successful. The budget is couple hundred
dollars at most. Any ideas?

Since the PIC aspect sounds incidental, you could try
http://www.zilog.com/z8encoremc/index.html

That's a working Motor Control system, [ PowerFETs and all ],
with USB debug, C compiler, and Motor, all for $199 ?

-jg
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Ian Bell
Guest





Posted: Mon Dec 12, 2005 4:19 pm    Post subject: Re: Asking for some PIC guidance Reply with quote

slavinger@yahoo.com wrote:

Quote:
Hi there,

Apologies in advance if I didn't pick quite the right newsgroups to
post this in. I'm a total newbie to PIC use in robotics or motor
actuation, however I'm very familiar with embedded development concepts
(Assembly on embedded M68K FPGA, etc). I'm very familiar with
languages like C, Assembly, and Basic. What I want to do is drive a
12V DC motor based on several sensor inputs. When sensor inputs
change, I want the motor to spin in the opposite direction from last
time. The logic would be very simple, and I need the hardware to be as
compact as possible. We're talking drive currents in the neighborhood
of several amps. Where do you suggest I start (buying hardware,
learning resources, etc)? Thanks in advance for all suggestions!

If you are familiar with the 68K you are going to find the PIC architecture
and its assembler strange to say the least. You might be better to use a
small Motorola 8 bitter like the HC11 for example..

Ian
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Rich Grise
Guest





Posted: Mon Dec 12, 2005 5:35 pm    Post subject: Re: Asking for some PIC guidance Reply with quote

On Sun, 11 Dec 2005 16:49:15 -0800, slavinger wrote:

Quote:
Hi there,

Apologies in advance if I didn't pick quite the right newsgroups to
post this in. I'm a total newbie to PIC use in robotics or motor
actuation, however I'm very familiar with embedded development concepts
(Assembly on embedded M68K FPGA, etc). I'm very familiar with
languages like C, Assembly, and Basic. What I want to do is drive a
12V DC motor based on several sensor inputs. When sensor inputs
change, I want the motor to spin in the opposite direction from last
time. The logic would be very simple, and I need the hardware to be as
compact as possible. We're talking drive currents in the neighborhood
of several amps. Where do you suggest I start (buying hardware,
learning resources, etc)? Thanks in advance for all suggestions!

Well, I see news:alt.fan.robotech, news:alt.robotware,
news:alt.sex.fetish.robots, news:alt.tv.robotech,
news:can.schoolnet.robotics, news:comp.robotics,
news:comp.robotics.misc, news:comp.robotics.research, and
a couple with prefixes like fj., sachsnet., and tnn.

Basic on-off/back-and-forth motor control isn't very hard, but
this one has been done to death, so to speak.

Have Fun!
Rich
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David L. Jones
Guest





Posted: Mon Dec 12, 2005 5:35 pm    Post subject: Re: Asking for some PIC guidance Reply with quote

Ian Bell wrote:
Quote:
slavinger@yahoo.com wrote:

Hi there,

Apologies in advance if I didn't pick quite the right newsgroups to
post this in. I'm a total newbie to PIC use in robotics or motor
actuation, however I'm very familiar with embedded development concepts
(Assembly on embedded M68K FPGA, etc). I'm very familiar with
languages like C, Assembly, and Basic. What I want to do is drive a
12V DC motor based on several sensor inputs. When sensor inputs
change, I want the motor to spin in the opposite direction from last
time. The logic would be very simple, and I need the hardware to be as
compact as possible. We're talking drive currents in the neighborhood
of several amps. Where do you suggest I start (buying hardware,
learning resources, etc)? Thanks in advance for all suggestions!

If you are familiar with the 68K you are going to find the PIC architecture
and its assembler strange to say the least. You might be better to use a
small Motorola 8 bitter like the HC11 for example..

Ian

Or simply use a high level language like C for the PIC.
The Microchip 18series C compiler is essentially free these days.
Or even easier - use a PIC-AXE chip, it has to be the easiest way to
program a micro for such a task. Essentially zero up-front cost too.
Silicon Chip mag have had plenty of PIC-AXE projects recently, and I
think one or more of them have been motor control.

Dave :)
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neon



Joined: 25 Feb 2006
Posts: 570

Posted: Fri Jul 07, 2006 1:20 pm    Post subject: Reply with quote

I don't think that a relay is fast enough and clean enough for motor reversal. The enertiia is bad enough as it is relay will add more time. Just a thought.
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