[PD] how to pd2stepper motor?

[Hans-Christoph Steiner]

On Oct 6, 2006, at 9:53 AM, Martin Peach wrote:

> Georg Holzmann wrote:
>> Hallo!
>>
>>> As far as steppers go it would be nice to have arduino commands  
>>> for steppers. It looks like the existing pduino firmware code can  
>>> only change one pin at a time, it would be nice to have a  
>>> parallel digital pin command with a mask like set_digital_outs 
>>> (int output_pattern, int mask) so the set bits in mask would be  
>>> changed, at the same time, according to output_pattern and the  
>>> zero bits would be unaffected.
>>
>> AFAIR it is like this - only that the output bits are splitted in  
>> 2 halfs (7 lower and 7 higher bits) ...
> In the Pd_firmware.pde code the pins are set on at a time even if  
> the data is sent as two bytes:
>
>      for(i=0; i<7; ++i) {
>        mask = 1 << i;
>        if( (digitalPinStatus & mask) && !(pwmStatus & mask) ) {
>          digitalWrite(i, inputData & mask);
>        }
>      }

I am definitely open to suggestions as to how to make the code work  
better.  I've been focused on the protocol design, so little  
optimization has happened.  In this case, its not quite as simple as  
just getting the byte from the serial port and writing it to the  
ports.  If a PWM is running, then you don't want to write to that  
port, that's what pwmStatus is doing.

 From what I read about the functions that write a byte at a time to  
the digital pins, you have to have all of the pins set to OUTPUT in  
order to use them.  But I could be wrong.

.hc



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