Help with PWM for 18F4520

Hi all,

I'm currenlty using a Microcontroller chip PIC18F4520 which is connected to ULN2003A and the stepper motor is sanyo denki 103H546 - 0440 Unipolar Stepper motor. I have the MPLAB C18 C Compiler for programming purposes.

Does anyone have a simple code so i can drive the motor for microstepping purposes as i am pretty confuse on the how to implement pwm to move the motor in microstep

Thanks

servos use pwm,
steppers use bridges

like this:http://hades.mech.northwestern.edu/images/d/d2/Unipolar_stepper_circuit_schematic.png

yours has 4 steps, see your diagram:
step1 = orange & red to ground
setp2 = redblue
step3=b,y
step4=y,r
then back to step 1

which pins on PIC are connected to which stepper input>? and do you know how to code any?


also note you should use protection diodes as shown