sinking inputs or sourcing inputs

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

From: rtstofer

To: p...@yahoogroups.com

Sent: Monday, January 23, 2006 9:11 AM

Subject: [piclist] Re: sinking inputs or sourcing inputs

Bill,

You know, there is nothing wrong with actually using switches as
shown in the datasheet.  In fact, there is every good reason to not
connect the PIC to the circuit until everything is debugged.

The downside is that the clock input will probably bounce and you
will get more than one step per operation.  But that's not important.

If you decide to try this, install the jumper such that the inputs
are held high and pulled to ground with the switches - connection 1-
2.  This way you won't even need pull-up resistors or any power
source other than the motor supply.

Ok, I'm to wire it up as per sinking inputs diagram with maybe a push on button switch between pins 2-3 so as to bump/pulse one full step(ms1 and ms2 pull high) with the motor connected and 12dcv? supplied to pins 6-7. 

I'm still waiting for the driver. I'll try this if this is correct.

thanks

bill 

Richard

--- In p...@yahoogroups.com, "Bill Davis" <wdavis@g...> wrote:
>
> Richard, that help clear things. I've seen the jumper 2-3 and I
was not clear about that. I just wasn't clear at all about the input
voltage pins 6-7.
> thanks for clear that up
> bill
>   ----- Original Message -----
>   From: rtstofer
>   To: p...@yahoogroups.com
>   Sent: Sunday, January 22, 2006 8:45 PM
>   Subject: [piclist] Re: sinking inputs or sourcing inputs>
>   Bill,
>
>   The sourcing/sinking thing is only about the logic signals
driving
>   the stepper driver chip and has nothing to do with the motor. 
The
>   only choice you have to make is whether your logic signals are
+5
>   for true or 0 for true according to the truth table.
>
>   I think you should jumper 2-3 and use the positive true outputs
from
>   the 16F88 to control the chip.  If you don't make any
connections to
>   MS1 and MS2 they will be 'inactive' and you will get 1/8 steps.
>
>   On the output side, you may have an issue.  The input voltage
has to
>   be between 12 and 24 volts (not 5V).  It is quite common to run
>   steppers at a much higher voltage than nameplate but I'm not up
to
>   speed on what to do here.  You also have a minimum current
>   requirement of 0.5A
>
>   I would put a couple of 20 ohm 5W resistors (0.6A) in place of
each
>   motor winding, connect the 16F88 (don't forget that logic ground
and
>   motor ground must be tied together), turn it on and watch the
>   voltages on the resistors.  Initially, I would just measure to
>   ground.
>
>   Then I would try a motor.  According to the datasheet the driver
is
>   current limited.  So, pick a motor rated at 12V or less and 0.5A
or
>   more and you should be fine.  Depending on your motor, you can
>   probably skip the resistor test.  I'm just overly cautious...
>
>   Print and read carefully the entire datasheet.  It is one of the
>   better ones around and is quite detailed on the motor
connections.
>
>   Richard
>
>   --- In p...@yahoogroups.com, "Bill Davis" <wdavis@g...> wrote:
>   >
>   >
>   >   ----- Original Message -----
>   >   From: JCullins
>   >   To: p...@yahoogroups.com
>   >   Sent: Sunday, January 22, 2006 4:50 PM
>   >   Subject: Re: [piclist] sinking inputs or sourcing inputs
>   >
>   >
>   >   Sinking means you give a ground to turn it on and sourcing
mean
>   you give it a voltage ( probably 5v ) It sounds like it has opto
>   isolation so you could drive either way, some chips do better
>   driving low rather that high.
>   >   Jim
>   >   Would I be in trouble if I try to a motor at 5dcv at 2.5 A
by
>   sourcing through F88 chip?
>   >   bill
>   >     ----- Original Message -----
>   >     From: wdavis364
>   >     To: p...@yahoogroups.com
>   >     Sent: Sunday, January 22, 2006 12:25 PM
>   >     Subject: [piclist] sinking inputs or sourcing inputs
>   >
>   >
>   >     I'm looking at the datasheet on MBC25081TB steppermotor
driver
>   by
>   >     Anihiem Automation. It shows two pinout diagrams one for
>   sinking
>   >     inputs and the other for sourcing inputs which are an the
same
>   pins.
>   >     Will someone tell me what is meant by sinking and sourcing
>   inputs?
>   >     thanks
>   >     bill
>   >
>   >
>   >
>   >
>   >
>   >
>   >     to unsubscribe, go to http://www.yahoogroups.com and
follow
>   the instructions
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----- Original Message -----

From: rtstofer

To: p...@yahoogroups.com

Sent: Sunday, January 22, 2006 7:33 PM

Subject: [piclist] Re: sinking inputs or sourcing inputs

Bill,

For this driver you have a jumper choice to make per page 2 of the
User Guide here: http://www.anaheimautomation.com/manuals/L010177%20-%
20MBC25081TB%20Users%20Guide.pdf  See Notes: ...

So, if you install the JP1 jumper at position 1-2, the driver will
assume you are going to pull the inputs low to make them active.  If
you install the jumper at position 2-3 the driver will assume you are
going to pull the inputs high to make them active.

Active/inactive are defined in the adjacent table.

So, the thing is, it doesn't matter which way you want to think about
the inputs to the driver; active high or active low.  Your choice.

Richard