Hello, I am a beginner in programming and I have the following problem. I need one timers for upper and lower limit sensors and a counter for the upper limit sensor, but I don't know what to do. Could someone help me, please. 
the program controls the sled up and down. When the tray is on the sensor, the timer keeps it down for a set time and then rises up. in the top position same. The counter calculates how many times the motion is repeated. For example, after five repetitions, the sled stops up and stays there. the restart will be restarted from the start button.
Here's the code:
#include <AccelStepper.h>
// Define the stepper and the pins it will use
AccelStepper stepper1(AccelStepper::DRIVER, 9, 8);
// Define our six input button pins
#define LEFT_PIN 4
#define STOP_PIN 3
#define RIGHT_PIN 2
#define START_PIN 5
#define UPPERLIMIT_PIN 7
#define LOWERLIMIT_PIN 6
// Define our analog pot input pin
#define SPEED_PIN 0
// Define our maximum and minimum speed in steps per second (scale pot to these)
#define MAX_SPEED 500
#define MIN_SPEED 0.1
void setup() {
// The only AccelStepper value we have to set here is the max speed, which is higher than we'll ever go
stepper1.setMaxSpeed(10000.0);
// Set up the three button inputs, with pullups
pinMode(LEFT_PIN, INPUT_PULLUP);
pinMode(STOP_PIN, INPUT_PULLUP);
pinMode(RIGHT_PIN, INPUT_PULLUP);
pinMode(START_PIN, INPUT_PULLUP);
pinMode(UPPERLIMIT_PIN, INPUT_PULLUP);
pinMode(LOWERLIMIT_PIN, INPUT_PULLUP);
}
void loop() {
static float current_speed = 0.0; // Holds current motor speed in steps/second
static int analog_read_counter = 1000; // Counts down to 0 to fire analog read
static char sign = 0; // Holds -1, 1 or 0 to turn the motor on/off and control direction
static int analog_value = 0; // Holds raw analog value.
// If a switch is pushed down (low), set the sign value appropriately
if (digitalRead(START_PIN) == 0) {
sign = -1;
}
else if (digitalRead(LEFT_PIN) == 0) {
sign = 1;
}
else if (digitalRead(RIGHT_PIN) == 0) {
sign = -1;
}
else if (digitalRead(STOP_PIN) == 0) {
sign = 0;
}
else if (digitalRead(UPPERLIMIT_PIN) == 1) {
sign = 0;
}
else if (digitalRead(LOWERLIMIT_PIN) == 1) {
sign = 1;
}
// We only want to read the pot every so often (because it takes a long time we don't
// want to do it every time through the main loop).
if (analog_read_counter > 0) {
analog_read_counter--;
}
else {
analog_read_counter = 3000;
// Now read the pot (from 0 to 1023)
analog_value = analogRead(SPEED_PIN);
// Give the stepper a chance to step if it needs to
stepper1.runSpeed();
// And scale the pot's value from min to max speeds
current_speed = sign * (((analog_value/1023.0) * (MAX_SPEED - MIN_SPEED)) + MIN_SPEED);
// Update the stepper to run at this new speed
stepper1.setSpeed(current_speed);
}
// This will run the stepper at a constant speed
stepper1.runSpeed();
}