Hello,
I’m using an Arduino Mega for a set up in which I need to control a linear stage actuator to move left and right between two points equipped with limit switches. One point as home and the other is the end of travel. I use a third switch to activate the actuator. I wrote a sketch but when I execute it nothing happens. I don’t know what is wrong.
The actuator is connected to a digital driver (DM542T) and set up worked with a generic sketch moving it back and forth. The problem arose when I added the limit switches to the set up. The following is the Sketch. Any help would be appreciated.
#include <AccelStepper.h>
#include <MultiStepper.h>
// Motor Control Parameters
#define MotorMaxSpeed 500 // This is the maximum speed for the motor movement in steps/second. Note: speeds over 1000 are unreliable according to the AccelStepper Class Reference document.
#define MotorSpeed 100 // This is the maximum speed for the motor movement in steps/second. Note: speeds over 1000 are unreliable according to the AccelStepper Class Reference document.
#define MotorAcceleration 500 // This is the motor accelration in steps/second^2
// Motor Position Parameters
#define MotorPositionAtBottom 1000 // This is the setpoint position of the motor at the lowest point
#define MotorPositionAtTop 0 // This is the setpoint position of the motor at the highest point
#define MotorPositionAtHome 100 // This is the setpoint position of the motor at the home point (slightly below the top point)
// Digital input pins
#define PinLimitSwitchBottom 22 // This is the analog input pin for the top movement limit switch
#define PinLimitSwitchTop 23 // This is the analog input pin for the bottom movement limit switch
#define PinStartButton 53 // This is the analog input pin for the motor start button press
// Digital output pins
#define PinMotorDirection 9 // This is the digital output pin for controlling the motor direction (CW)
#define PinMotorPulse 8 // This is the digital output pin for controlling the motor control pulses (CLK)
// Define a Accel stepper motor 1 for arduino
AccelStepper stepper(1, PinMotorPulse, PinMotorDirection);
// Stepper Motor Statuses
enum RepeatBlockTypes {MotorAtHome, MotorMovingDown, MotorMovingUp, MotorHoming}; // These are the possible states that the stepper motor can be in
// Prepare the Arduino Mega 2560 board
void setup()
{
// Loop over the digital pins to set most pins as digital outputs
for (int i = 2; i < 53; i++)
{
if ((i != PinLimitSwitchBottom) && (i != PinLimitSwitchTop) && (i != PinStartButton))
{
pinMode(i, OUTPUT); // Declare these pins as digital output
}
}
// Declare these pins as digital inputs
pinMode(PinLimitSwitchBottom, INPUT);
pinMode(PinLimitSwitchTop, INPUT);
pinMode(PinStartButton, INPUT);
// Set up the motor settings
stepper.setMaxSpeed(MotorMaxSpeed);
stepper.setAcceleration(MotorAcceleration);
stepper.moveTo(MotorPositionAtHome); // Start the motor moving to the home position, slightly below the top limit switch
stepper.setSpeed(MotorSpeed);
}
// Loop indefinitely
void loop()
{
// Read the digital input values
int BottomLimitSwitchValue = digitalRead(PinLimitSwitchBottom); // Read the value of the bottom limit switch (LOW = the switch is open, HIGH = the switch is closed)
int TopLimitSwitchValue = digitalRead(PinLimitSwitchTop); // Read the value of the top limit switch (LOW = the switch is open, HIGH = the switch is closed)
int MotorStartButtonValue = digitalRead(PinStartButton); // Read the value of the motor start button (LOW = the button is pressed, HIGH = the button is not pressed)
// Choose what to do based on the limit switch and start button press values
// BottomLimitSwitchValue is a safety switch, reverse the motor to move up
if (BottomLimitSwitchValue == HIGH) // HIGH means the bottom limit switch pin is reading the 5 V state (limit switch is pressed)
{
stepper.stop();
stepper.moveTo(MotorPositionAtTop); // Tell the motor to go up to the top position, it should hit the top limit switch and then reverse to home
}
// TopLimitSwitchValue is a safety switch, reverse the motor to move down
else if (TopLimitSwitchValue == HIGH) // HIGH means the top limit switch pin is reading the 5 V state (limit switch is pressed)
{
stepper.stop();
stepper.setCurrentPosition(0); // Sets the position counter of the motor to zero in this home position
stepper.setSpeed(MotorSpeed); // Setting the current position has a side effect of setting the speed to 0, so reset it.
stepper.moveTo(MotorPositionAtHome); // Tell the motor to go down to the home position
}
// Only if no limit switch is pressed, check to see if the start button is pressed
else if (MotorStartButtonValue == HIGH) // HIGH means the start button pin is reading the 5 V state (start button is pressed)
{
if (stepper.distanceToGo() == 0)
{
stepper.moveTo(MotorPositionAtBottom); // Tell the motor to go down to the bottom position
}
}
// Tell the motor to continue running, if necessary, to its next set point location. This run command must be called frequently in a loop to keep the motor running
if (stepper.distanceToGo() != 0)
{
stepper.run();
}
}
