Page 49 - Ai Robogenius

Final Output

The LED will light up when any object is detected by the PIR sensor. If no object is detected near
the sensor, the LED will remain off. This confirms that the sensor is detecting changes in infrared
radiation.

BUILD AUTOMATIC STREETLIGHT

An automatic streetlight circuit uses a photoresistor to detect light levels and automatically turn
on or off the LED based on the ambient light. When it gets dark, the photoresistor detects the lower
light levels, triggering the LED to turn on.

To build the Automatic Streetlight circuit, follow the given steps:

STEP - 1 Open a new circuit window in Tinkercad and rename your project as Automatic
Streetlight Circuit.

STEP - 2 Connect the positive terminal of the 9V battery to the positive rail on the breadboard.

STEP - 3 Connect the negative terminal of the 9V battery to the negative rail on the
breadboard.

STEP - 4 Connect one leg of the photoresistor to row 2, column i and the other leg to row 3,
column i.

STEP - 5 Place the first 220K ohm resistor on the breadboard and connect one end of the
resistor to row 3, column h (where the photoresistor is connected) and the other end
to row 7, column h.

STEP - 6 Place the second 330-ohm resistor on the breadboard and connect one end of the
resistor to row 7, column i and the other end to row 11, column i.

STEP - 7 Connect the anode (positive leg) of the LED to row 11, column j.

STEP - 8 Connect the cathode (negative leg) of the LED to row 14, column j.

Introduction to Sensors in Tinkercad
47