Yes Alain, go RTFM and come back with another comic ;-)
This has been covered almost as many times as "disable analog functions when using pins as digital" but since it continues to create false...
Published on - 2nd July 2010 16:12
Number of Views: 7352
I have been thinking for a while, how to put togeter a simple microstepper controller without using a ready made commercial driver.
At the end, I came up with this simple project capable to drive unipolar stepper motor in three different modes
FULL STEP
HALF STEP
MICRO STEP
The Pic micro used in this work is a Pic 16F628 a powerfull small micro with PWM capability. With this MCU plus a 74HC04 and a74HC86 the controller will produce 20 microsteps out of a nominal motor step.
An additional improvement of this controller, is the capability to accept travel commands of 24 Bits, wich gives to the user the possibility to send positioning profile of over 16 millions steps.
Controller accept commands via TTL serial port @ 9600,n,8,1 and return an (Ack) once the positioning profile has been completed.
Download the zipped MicroStepper.zip file which contains schematic + software + user manual
Also attached is a simple stepper controller example called Stepper_MK2.zip
Re: Timer 0 not accurate
you also can play with the OSCTUNE register ... ( datasheet DS39631E-page 27 )
Acetronics2 Today, 13:57most of time it's enough to get usable precision without tuning the OSC Crystal ...
Alain