SunFounder R3, Manual, Page: 323 / 527

SunFounder uno-and-mega-kit
Code Analysis 21-2 setSpeed() function
//speed of 180 per minute
stepper. setSpeed ( 180 ); //set the motor speed in rotations per minute(RPMs)
setSpeed(rpms):
Sets the motor speed in rotations per minute (RPMs). This function doesn’t make the motor turn,
just sets the speed at which it will when you call step().
rpms : the speed at which the motor should turn in rotations per minute - a positive number (long)
loop() function
void loop ()
{
//get analog value
int val = analogRead ( 0 ); //Read the value of the potentiometer
//current reading minus the reading of history
stepper. step (val - previous); //Turn the motor in val-previous steps
//store as prevous value
previous = val; //the value of potentiometer assignment to variable previous
}
The main program is to read the value of A0 first and then set the number of steps of stepper motor rotation according
to the value of A0.
step(steps): Turns the motor a specific number of steps, at a speed determined by the most recent call to setSpeed().
This function is blocking; that is, it will wait until the motor has finished moving to pass control to the next line in
your sketch. For example, if you set the speed to, say, 1 RPM and called step(100) on a 100-step motor, this function
would take a full minute to run. For better control, keep the speed high and only go a few steps with each call to step().
steps:
the number of steps to turn the motor - positive to turn one direction, negative to turn the other (int).
7.20 Lesson 20 Simple Creation-Stopwatch
7.20.1 Introduction
In this lesson, we will use a 4-digit 7-segment display to make a stopwatch.
7.20. Lesson 20 Simple Creation-Stopwatch 317