Re: dispatcher function questions

[garrett beaubien <garrettb77-at-yahoo.com>]

Hi Fred,

Thank you for your reply.


> 
> > When I try and
> > read the value from the actual hardware, (ie
> > *counts[0] = inb(257); *counts[1] = 0; *counts[2]
> =
> > 0;), the axis will not home.  For both of these
> test
> > compilations, the rest of the code is identical. 
> I
> > coded the function that reads the home switch to
> > always return a 0.  I guess I should mention I
> only
> > have a single axis with hardware, but the emc.ini
> file
> > has 3 axes.
> 
> What kind of encoder board do you have? Are you sure
> you can read valid
> feedback from it? When you do this:
> 
> *counts[0] = inb(257);
> 
> this looks like you're trying to read a byte of data
> at I/O address 257.
> One byte of data is quite small for position
> feedback. inb() also
> returns an unsigned byte, so you'll get values in
> count[0] from 0.0 to
> 255.0, in 1.0 increments.

I have a single axis board that I made myself.  It
uses the LS7166 counter chip (same as servo to go). 
To read counter values I actually read 3 successive
bytes.  right now nothing workes except the
initialization function that I use to set the
amplifier drive to zero.  I was thinking that I would
try and get the encoder working first so that at least
I could see the readout change by turning the motor
shaft.     

I did learn something else about my set-up.  I
couldn't get the rtl_printf() working, so I used the
printk() function, and viewed the results with dmesg. 
Did crash my system a couple of times, but as they
say... No Guts, No Glory :)
When I viewed the first value returned from the
extEncoderReadAll function, it was 0, every subsequent
value was a single non-zero value (as the drive to the
amp also is not working, the value was always the
same).  I guess this is preventing it from homing.  I
think I may do what you suggest and try running as a
non-realtime process.  I'll also take a look at the
dro.c code you mentioned, and see if I can get mine to
work with that.  


Thanks again for all your help.  Hopefully I can get a
few free hours this weekend to get something working. 


Garrett.

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