Harry Anderson
Published © GPL3+

Customer Limiting Shop Door Assistant

Large shops used staff to limit customer entry during lockdown. Small shops which don't have extra staff, can use this solution.

BeginnerFull instructions provided3 hours500
Customer Limiting Shop Door Assistant

Things used in this project

Hardware components

Arduino Nano R3
Arduino Nano R3
×1
5V 2.5A Switching Power Supply
Digilent 5V 2.5A Switching Power Supply
×1
5 mm LED: Green
5 mm LED: Green
×6
5 mm LED: Red
5 mm LED: Red
×6
LED, Amber
LED, Amber
×5
Pushbutton switch 12mm
SparkFun Pushbutton switch 12mm
×2
7 Segment LED Display, Red
7 Segment LED Display, Red
×1
Ultrasonic Sensor - HC-SR04 (Generic)
Ultrasonic Sensor - HC-SR04 (Generic)
×2
Power MOSFET N-Channel
Power MOSFET N-Channel
×3
Resistor 330 ohm
Resistor 330 ohm
×12
Resistor 100 ohm
Resistor 100 ohm
×6
Resistor 220 ohm
Resistor 220 ohm
×7

Software apps and online services

Arduino IDE
Arduino IDE

Story

Read more

Schematics

Other Component Schematics

Only one seven segment display was used here. Buttons for increasing max and min person count and then the two ultrasonic distance sensors. The analogue pins are used as digital pins.

LED Schematics

Use a power supply for the 5V line to provide enough current while using the digital pins on the Arduino to switch them on or off. Make sure the Arduino ground is connected to the power supply ground.

Code

Arduino Code

C/C++
Serial can be removed after testing.
//Shop Door Traffic Light
//Rev.1: H.Anderson-Chapman 09/06/2020


//LED sign pins
int redLedPin = 3;
int amberLedPin = 8;
int greenLedPin = 2;

//Entry ultrasonic sensor Pins
int entryPinOut = 5;
int entryPinIn = 6;

//Exit ultrasonic sensor Pins
int exitPinOut = 7;
int exitPinIn = 9;

//Seven segment display pins
int GPin = A5;
int FPin = A4;
int EPin = A1;
int DPin = 12;
int CPin = A0;
int BPin = A2;
int APin = A3;

//Button pins
int buttonUpPin = 10;
int buttonDownPin = 11;

//Initialising variables
int personCount = 0;
int maxPersonCount = 0;

void setup() {
  // put your setup code here, to run once:
  //Setting the sign LED pins
  pinMode(redLedPin, OUTPUT);
  pinMode(amberLedPin, OUTPUT);
  pinMode(greenLedPin, OUTPUT);

  //Setting the entry ultrasonic sesnor pins
  pinMode(entryPinOut, OUTPUT);
  pinMode(entryPinIn, INPUT);

  //Setting the exit ultrasonic sesnor pins
  pinMode(exitPinOut, OUTPUT);
  pinMode(exitPinIn, INPUT);

  //Setting seven segment display pins
  pinMode(GPin, OUTPUT);
  pinMode(FPin, OUTPUT);
  pinMode(EPin, OUTPUT);
  pinMode(DPin, OUTPUT);
  pinMode(CPin, OUTPUT);
  pinMode(BPin, OUTPUT);
  pinMode(APin, OUTPUT);

  //Setting button pins
  pinMode(buttonUpPin, INPUT);
  pinMode(buttonDownPin, INPUT);

  //Observe with terminal while in testing
  Serial.begin(9600);
}

void loop() {
  //variables to be used
  long entryDuration, entryCm, exitDuration, exitCm;

  //Any distance under this value (cm) is a confirmed scan
  int sensorLimit = 15;

  //Writing the final digit of remaining spaces to the 7-segment display
  segmentNumber((maxPersonCount - personCount) % 10);

  //taking readings for the buttons
  bool upButton = digitalRead(buttonUpPin);
  bool downButton = digitalRead(buttonDownPin);

  //If the increase button has been pressed, increase the person count
  if (upButton) {
    maxPersonCount++;
    Serial.println("Max person increased to:");
    Serial.println(maxPersonCount);
    delay(500);
  }
  //If the decrease button has been pressed, decrease the person count if possible
  else if (downButton & maxPersonCount > 0) {
    maxPersonCount--;
    Serial.println("Max person decreased to:");
    Serial.println(maxPersonCount);
    delay(500);
  }

  //If current customer count is greater or equal to max allowance, show the red sign.
  if (personCount >= maxPersonCount) {
    digitalWrite(redLedPin, HIGH);
    Serial.println("Red, wait for person to leave");
  }

  //Otherwise show the amber sign and detect for an entry
  else {
    digitalWrite(amberLedPin, HIGH);

    //Taking a distance sensor reading
    digitalWrite(entryPinOut, HIGH);
    delayMicroseconds(2);
    digitalWrite(entryPinOut, LOW);
    delayMicroseconds(10);
    entryDuration = pulseIn(entryPinIn, HIGH);

    //Converting to cm
    entryCm = entryDuration / 29 / 2;
    Serial.println("Entry Sensor:");
    Serial.println(entryCm);

    //If the distance is below the sensorLimit and there is space, the green light will turn on
    if (entryCm <= sensorLimit & personCount < maxPersonCount) {
      digitalWrite(amberLedPin, LOW);
      digitalWrite(greenLedPin, HIGH);
      personCount++; //Noting the entry of a person

      Serial.println("Green, enter, person count:");
      Serial.println(personCount);

      delay(3000);
    }
  }

  //If a person can leave, detect for one
  if (personCount > 0) {

    //Taking a distance sensor reading for exiting sensors
    digitalWrite(exitPinOut, HIGH);
    delayMicroseconds(2);
    digitalWrite(exitPinOut, LOW);
    delayMicroseconds(10);
    exitDuration = pulseIn(exitPinIn, HIGH);

    //Converting to cm
    exitCm = exitDuration / 29 / 2;
    Serial.println("Exit Sensor:");
    Serial.println(exitCm);

    if (exitCm <= sensorLimit) {
      personCount--;
      //Putting all lights on to indicate the departure has been read.
      digitalWrite(amberLedPin, HIGH);
      digitalWrite(greenLedPin, HIGH);
      digitalWrite(redLedPin, HIGH);

      Serial.println("Person left the room, person Count:");
      Serial.println(personCount);
      delay(3000);
    }

  }

  //resetting the lights
  digitalWrite(amberLedPin, LOW);
  digitalWrite(greenLedPin, LOW);
  digitalWrite(redLedPin, LOW);
}

//A function to convert the number to display into the right 7-segment outputs.
void segmentNumber(int desiredNumber) {
  digitalWrite(APin, LOW);
  digitalWrite(FPin, LOW);
  digitalWrite(GPin, LOW);
  digitalWrite(CPin, LOW);
  digitalWrite(DPin, LOW);
  digitalWrite(EPin, LOW);
  digitalWrite(BPin, LOW);
  switch (desiredNumber) {
    case 0:
      digitalWrite(APin, HIGH);
      digitalWrite(BPin, HIGH);
      digitalWrite(CPin, HIGH);
      digitalWrite(EPin, HIGH);
      digitalWrite(DPin, HIGH);
      digitalWrite(FPin, HIGH);
      break;
    case 1:
      digitalWrite(BPin, HIGH);
      digitalWrite(CPin, HIGH);
      break;
    case 2:
      digitalWrite(APin, HIGH);
      digitalWrite(BPin, HIGH);
      digitalWrite(GPin, HIGH);
      digitalWrite(EPin, HIGH);
      digitalWrite(DPin, HIGH);
      break;
    case 3:
      digitalWrite(APin, HIGH);
      digitalWrite(BPin, HIGH);
      digitalWrite(CPin, HIGH);
      digitalWrite(GPin, HIGH);
      digitalWrite(DPin, HIGH);
      break;
    case 4:
      digitalWrite(FPin, HIGH);
      digitalWrite(BPin, HIGH);
      digitalWrite(GPin, HIGH);
      digitalWrite(CPin, HIGH);
      break;
    case 5:
      digitalWrite(APin, HIGH);
      digitalWrite(FPin, HIGH);
      digitalWrite(GPin, HIGH);
      digitalWrite(CPin, HIGH);
      digitalWrite(DPin, HIGH);
      Serial.println("5");
      break;
    case 6:
      digitalWrite(APin, HIGH);
      digitalWrite(FPin, HIGH);
      digitalWrite(GPin, HIGH);
      digitalWrite(CPin, HIGH);
      digitalWrite(DPin, HIGH);
      digitalWrite(EPin, HIGH);
      break;
    case 7:
      digitalWrite(BPin, HIGH);
      digitalWrite(CPin, HIGH);
      digitalWrite(APin, HIGH);
      break;
    case 8:
      digitalWrite(APin, HIGH);
      digitalWrite(FPin, HIGH);
      digitalWrite(GPin, HIGH);
      digitalWrite(CPin, HIGH);
      digitalWrite(DPin, HIGH);
      digitalWrite(EPin, HIGH);
      digitalWrite(BPin, HIGH);
      break;
    case 9:
      digitalWrite(FPin, HIGH);
      digitalWrite(BPin, HIGH);
      digitalWrite(GPin, HIGH);
      digitalWrite(CPin, HIGH);
      digitalWrite(APin, HIGH);
      break;
    //Default shows 0, for when a negative value shows, no one can enter.
    default:
      digitalWrite(APin, HIGH);
      digitalWrite(BPin, HIGH);
      digitalWrite(CPin, HIGH);
      digitalWrite(EPin, HIGH);
      digitalWrite(DPin, HIGH);
      digitalWrite(FPin, HIGH);
  }
  return;
}

Credits

Harry Anderson

Harry Anderson

1 project • 0 followers

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