AVR-Chat

Dear : 

i am looking for help to use PWM @mega8535 To contrl Dc Motors
but there is a problem 


can any one help me by code and show how can i get the motors fast and 
slow ?? 

thanks

I am controlling the motors by using avr micro control 

the way to increase or decrease the motor speed is the PWM 

and it is my first time to control motors 

so i am looking for help how to use the PWM  and how can i connect the 
motors to controller 

i know that i must use h-bridge or relay (( i'm using h-bridge))

thanks

An electric motor is basically a Hall Effect device.  By increasing and 
decreasing the magnetic flux density you increase and decrease the 
angular velocity at which the "armature" rotates inside the fixed 
magnetic field of the "field" windings...increase the flux density and 
the velocity increases, decrease and it slows.  Varying the field will 
do likewise with a fixed armature flux density, within limits, but the 
effect is reversed.

Is that what you're looking for?

Google is your friend.


REB


ktal3at wrote:

>Dear : 
>
>i am looking for help to use PWM @mega8535 To contrl Dc Motors
>but there is a problem 
>
>
>can any one help me by code and show how can i get the motors fast and 
>slow ?? 
>
>thanks 
>
>
>
>  
>

It sounds like you have a need to learn some basic, and very basic at 
that, concepts of electricity.  The reason for my smartalecy previous 
remark, and the suggestion to use google.  Do a search using the 
keywords - DC motor control PWM.  You should get a gazillion or so hits.


REB


ktal3at wrote:

>I am controlling the motors by using avr micro control 
>
>the way to increase or decrease the motor speed is the PWM 
>
>and it is my first time to control motors 
>
>so i am looking for help how to use the PWM  and how can i connect the 
>motors to controller 
>
>i know that i must use h-bridge or relay (( i'm using h-bridge))
>
>thanks 
>
>
>
>
>  
>

What kind of motor are you trying to control?  Synchronous AC motors do 
not work by PWM.  Stepper motors like the kind used in satellite dish 
feed polarotors use PWM. Other steppers require a set of phased pulses 
which vary the pulse frequency to control the speed.  Regular DC motors 
can be controlled in a variety of ways.

Zack

On Mon, 4 Feb 2008, ktal3at wrote:

> I am controlling the motors by using avr micro control
>
> the way to increase or decrease the motor speed is the PWM
>
> and it is my first time to control motors
>
> so i am looking for help how to use the PWM  and how can i connect the
> motors to controller
>
> i know that i must use h-bridge or relay (( i'm using h-bridge))
>
> thanks
>
>
>
>

Regular DC motors 
> can be controlled in a variety of ways.
> 


How can i control them by using PWM ?? 

can u help me to generate an ASM Code for it on ATMEGA 8535 ?

ktal3at wrote:
>  Regular DC motors 
> 
>>can be controlled in a variety of ways.
>>
> 
> 
> 
> How can i control them by using PWM ?? 
> 
> can u help me to generate an ASM Code for it on ATMEGA 8535 ? 

   What kind of motors are you using?  What kind of H-bridge.  Your 
motor and H-bridge determine what the frequency is that you can use. 
For instance, cheapie Mabuchi motors like those used in toys and some 
gearboxes can't deal well with higher than 500 Hz.  The L293 H-bridge 
can't deal with a PWM frequency higher than about 1-2KHz (I blew the top 
off the chip when I accidentally used 19KHz on one!)

We need more details.

   If you don't want to write in assembly, and don't have money for a 
compiler then you can use avr-gcc, which runs on Mac, Linux and Windows 
and gives a higher level C environment.


DLC
-- 
---------------------------------------
Dennis Clark    TTT Enterprises
---------------------------------------

the main problem for me how to use or generate PWM For increase and 
decrease the speed

or can u help me to reach the PID algorithm ? ?

how can i reach it ? ? ?  ??

It takes one instruction to turn pwm on, one instruction to adjust the duty cycle (example: OCR0=128;) Perhaps a short scan of the datasheet will clear most of this up?

-----Original Message-----
From: ktal3at <ktal3at@yahoo.com>
To: AVR-Chat@yahoogroups.com
Sent: Tue, 5 Feb 2008 6:30 am
Subject: [AVR-Chat] Re: PWM Help



the main problem for me how to use or generate PWM For increase and 
decrease the speed 





 
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--- In AVR-Chat@yahoogroups.com, "ktal3at" <ktal3at@...> wrote:
>
> I am controlling the motors by using avr micro control 
> 
> the way to increase or decrease the motor speed is the PWM 
> 
> and it is my first time to control motors 
> 
> so i am looking for help how to use the PWM  and how can i connect 
the 
> motors to controller 
> 
> i know that i must use h-bridge or relay (( i'm using h-bridge))
> 
> thanks
>hi there 
you will have lots of problem, i trid it
by

> --- In AVR-Chat@yahoogroups.com, "ktal3at" <ktal3at@...> wrote:
>>
>> I am controlling the motors by using avr micro control
>>
>> the way to increase or decrease the motor speed is the PWM
>>
>> and it is my first time to control motors
>>
>> so i am looking for help how to use the PWM  and how can i connect
> the
>> motors to controller
>>
>> i know that i must use h-bridge or relay (( i'm using h-bridge))
>>
>> thanks
>>hi there
> you will have lots of problem, i trid it
> by

  Nonsense, there's nothing to it.  The AVR/ATMEGA parts have a single
match register that is used to compare against the PWM timer to
determine duty cycle.  Set your prescale to get the frequency that you
want (usually around 1KHz) and connect the PWM output as you need for
the type of drive that you want: locked-antiphase or sign/magnitude. 
Google is your friend, it can find many examples of what I just tersely
described.

DLC
-- 
Dennis Clark
TTT Enterprises

Hello folks,

I have coded the AVR's for some time now and want to start looking at the AVR32's. The problem is I don't know how to start.

How do I program it? I want to build my own programmer from scratch, preferrably the simplest one (though it need not to be simple in the sense that
I can build it with four resistors and I gigantic soldering pen). I can make PCB's and stuff like that.

I found this link on google http://www.ixbat.de/index.php?page_id=236
is this one really the simplest one?

can I use my normal isp10 programmer with only four resistors to the AVR32's? if no, why not?

Best regards,

Manne

There is an AVR32 section of the AVRFreaks list. You are likely to get  
much better answers there.

Jim Wagner

On Feb 13, 2008, at 2:24 PM, Manne Tallmarken wrote:

> Hello folks,
>
> I have coded the AVR's for some time now and want to start looking  
> at the AVR32's. The problem is I don't know how to start.
>
> How do I program it? I want to build my own programmer from scratch,  
> preferrably the simplest one (though it need not to be simple in the  
> sense that
> I can build it with four resistors and I gigantic soldering pen). I  
> can make PCB's and stuff like that.
>
> I found this link on google http://www.ixbat.de/index.php?page_id=236
> is this one really the simplest one?
>
> can I use my normal isp10 programmer with only four resistors to the  
> AVR32's? if no, why not?
>
> Best regards,
>
> Manne
>
>
> 



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