Smart Home Automated Blinds

Create a wooden gear to pull the blind cord.

1. Cut a circular gear from wood or chipboard (diameter depends on your blind cord length).
2. Glue wooden circles on both sides to prevent the cord from slipping out.
3. Build a wooden frame with a hole to hold the stepper motor in a stable position.
4. Mount the stepper motor on the frame.
5. Attach the gear to the motor shaft (use a bottle cap with a hole as a coupler if needed).

Wire the ULN2003 driver and stepper motor to Arduino.

1. Connect the stepper motor's 4-wire cable to the ULN2003 driver module.
2. Connect the driver module to Arduino: IN1→Pin 11, IN2→Pin 10, IN3→Pin 9, IN4→Pin 8.
3. Place the power supply module on the breadboard.
4. Connect Arduino GND to the breadboard's GND rail.
5. Connect the ULN2003 driver's GND and power pins to the breadboard.

Upload stepper control code to Arduino.

1. Open Arduino IDE and create a new sketch.
2. Copy the complete stepper control sketch below.
3. Upload to your Arduino.
4. The Arduino will listen for serial commands from the Raspberry Pi.

#include <Stepper.h>

const int stepsPerRevolution = 2048;
const int rolePerMinute = 10;

Stepper myStepper(stepsPerRevolution, 8, 10, 9, 11);

void setup() {
  myStepper.setSpeed(rolePerMinute);
  Serial.begin(9600);
}

String RecentInput = "";

void loop() {
  if (Serial.available() > 0) {
    String IncomingInput = Serial.readString();
    RecentInput = IncomingInput;
    
    if (RecentInput == "ROLL UP!") {
      Serial.println("clockwise");
      myStepper.step(stepsPerRevolution);
    }
    
    if (RecentInput == "ROLL DOWN!") {
      Serial.println("counterclockwise");
      myStepper.step(-stepsPerRevolution);
    }
  }
}

Enable serial communication between Pi and Arduino.

1. On Raspberry Pi, open a terminal.
2. Run: sudo raspi-config
3. Navigate to Interface Options → Serial Port.
4. Enable serial hardware but disable serial login shell.
5. Reboot your Raspberry Pi.
6. Install Python serial library: sudo apt-get install python-serial
7. Also install: sudo pip install pyserial
8. Connect Arduino to Raspberry Pi via USB.
9. Find the port: ls /dev/tty*
10. Look for /dev/ttyACM0 or similar.

Build a Python GUI to control the blinds.

1. Create a new Python file on Raspberry Pi: nano blinds_control.py
2. Copy the Python interface code (available in the full tutorial source).
3. The interface creates 3 buttons: Roll Up, Roll Down, and Stop.
4. Adjust the serial port in the code if needed (default is /dev/ttyACM0).
5. Save and exit (Ctrl+X, Y, Enter).

Verify the complete system works.

1. Run the Python interface: python3 blinds_control.py
2. A window with 3 buttons should appear.
3. Click 'Roll Up' and watch the motor turn clockwise.
4. Click 'Roll Down' and watch it turn counterclockwise.
5. Attach the blind cord to the gear and test with actual blinds.