User manual

 2012 Microchip Technology Inc. DS41629A-page 5
5.3.6 UNI/O
®
Memory Chip ............................................................................ 44
5.3.7 Speed Control ........................................................................................ 44
5.3.8 Current Control ...................................................................................... 44
5.4 Demo Software ....................................................................................... 45
5.4.1 Introduction ............................................................................................ 45
5.4.2 The Motor Control GUI Application ........................................................ 45
5.5 Optimizing Stepper Motor Parameters ................................................... 46
5.5.1 Stepper Motor Closed-Loop Drive Overview ......................................... 46
5.5.2 Optimizing DUTY_SCALE and SPEED_SCALING_CONST ................ 47
Appendix A. Board Layout and Schematics
A.1 Introduction ............................................................................................. 49
Appendix B. Conversion Factors
B.1 Conversion Factor Derivations ............................................................... 55
B.2 Start-up: Speed ...................................................................................... 55
B.3 Slow Step ............................................................................................... 55
B.4 Stepper Run and Stop Percentages ....................................................... 56
B.5 Degrees Per Step ................................................................................... 56
B.6 Stepper: Min and Max Duty Percent ....................................................... 56
B.7 Constants Derived From Stepper Parameters ....................................... 56
B.7.1 DUTY_SCALE Constant ........................................................................ 56
B.7.2 SPEED_SCALING_CONST Constant ................................................... 57
B.8 uStep Table ............................................................................................ 57