Update stepper library: High-speed stepping mod and timer rollover fix

libraries/Stepper/Stepper.h

@@ -1,10 +1,11 @@
 /*
-  Stepper.h - - Stepper library for Wiring/Arduino - Version 0.4
+  Stepper.h - - Stepper library for Wiring/Arduino - Version 0.5
 
   Original library     (0.1) by Tom Igoe.
   Two-wire modifications   (0.2) by Sebastian Gassner
   Combination version   (0.3) by Tom Igoe and David Mellis
   Bug fix for four-wire   (0.4) by Tom Igoe, bug fix from Noah Shibley
+  High-speed stepping mod and timer rollover fix   (0.5) by Eugene Kozlenko
 
   Drives a unipolar or bipolar stepper motor using  2 wires or 4 wires
 
@@ -18,7 +19,8 @@
   A slightly modified circuit around a Darlington transistor array or an L293 H-bridge
   connects to only 2 microcontroler pins, inverts the signals received,
   and delivers the 4 (2 plus 2 inverted ones) output signals required
-  for driving a stepper motor.
+  for driving a stepper motor.  Similarly the Arduino motor shields 2 direction pins
+  may be used.
 
   The sequence of control signals for 4 control wires is as follows:
 
@@ -65,7 +67,7 @@ class Stepper {
 
     int direction;        // Direction of rotation
     int speed;          // Speed in RPMs
-    unsigned long step_delay;    // delay between steps, in ms, based on speed
+    unsigned long step_delay;    // delay between steps, in us, based on speed
     int number_of_steps;      // total number of steps this motor can take
     int pin_count;        // whether you're driving the motor with 2 or 4 pins
     int step_number;        // which step the motor is on
@@ -76,7 +78,7 @@ class Stepper {
     int motor_pin_3;
     int motor_pin_4;
 
-    long last_step_time;      // time stamp in ms of when the last step was taken
+    unsigned long last_step_time;      // time stamp in us of when the last step was taken
 };
 
 #endif

libraries/Stepper/Stepper.cpp → libraries/Stepper/stepper.cpp

@@ -1,10 +1,11 @@
 /*
-  Stepper.cpp - - Stepper library for Wiring/Arduino - Version 0.4
+  Stepper.cpp - - Stepper library for Wiring/Arduino - Version 0.5
 
   Original library     (0.1) by Tom Igoe.
   Two-wire modifications   (0.2) by Sebastian Gassner
   Combination version   (0.3) by Tom Igoe and David Mellis
   Bug fix for four-wire   (0.4) by Tom Igoe, bug fix from Noah Shibley  
+  High-speed stepping mod and timer rollover fix   (0.5) by Eugene Kozlenko
 
   Drives a unipolar or bipolar stepper motor using  2 wires or 4 wires
 
@@ -18,7 +19,8 @@
   A slightly modified circuit around a Darlington transistor array or an L293 H-bridge
   connects to only 2 microcontroler pins, inverts the signals received,
   and delivers the 4 (2 plus 2 inverted ones) output signals required
-  for driving a stepper motor.
+  for driving a stepper motor. Similarly the Arduino motor shields 2 direction pins
+  may be used.
 
   The sequence of control signals for 4 control wires is as follows:
 
@@ -57,7 +59,7 @@ Stepper::Stepper(int number_of_steps, int motor_pin_1, int motor_pin_2)
   this->step_number = 0;      // which step the motor is on
   this->speed = 0;        // the motor speed, in revolutions per minute
   this->direction = 0;      // motor direction
-  this->last_step_time = 0;    // time stamp in ms of the last step taken
+  this->last_step_time = 0;    // time stamp in us of the last step taken
   this->number_of_steps = number_of_steps;    // total number of steps for this motor
 
   // Arduino pins for the motor control connection:
@@ -87,7 +89,7 @@ Stepper::Stepper(int number_of_steps, int motor_pin_1, int motor_pin_2, int moto
   this->step_number = 0;      // which step the motor is on
   this->speed = 0;        // the motor speed, in revolutions per minute
   this->direction = 0;      // motor direction
-  this->last_step_time = 0;    // time stamp in ms of the last step taken
+  this->last_step_time = 0;    // time stamp in us of the last step taken
   this->number_of_steps = number_of_steps;    // total number of steps for this motor
 
   // Arduino pins for the motor control connection:
@@ -112,7 +114,7 @@ Stepper::Stepper(int number_of_steps, int motor_pin_1, int motor_pin_2, int moto
 */
 void Stepper::setSpeed(long whatSpeed)
 {
-  this->step_delay = 60L * 1000L / this->number_of_steps / whatSpeed;
+  this->step_delay = 60L * 1000L * 1000L / this->number_of_steps / whatSpeed;
 }
 
 /*
@@ -131,9 +133,9 @@ void Stepper::step(int steps_to_move)
   // decrement the number of steps, moving one step each time:
   while(steps_left > 0) {
   // move only if the appropriate delay has passed:
-  if (millis() - this->last_step_time >= this->step_delay) {
+  if (micros() - this->last_step_time >= this->step_delay || micros() < this->last_step_time) {
       // get the timeStamp of when you stepped:
-      this->last_step_time = millis();
+      this->last_step_time = micros();
       // increment or decrement the step number,
       // depending on direction:
       if (this->direction == 1) {
@@ -216,5 +218,5 @@ void Stepper::stepMotor(int thisStep)
 */
 int Stepper::version(void)
 {
-  return 4;
+  return 5;
 }