Sensors
Automatic night light
A light that turns itself on when the room gets dark, using a light-dependent resistor.
What you get
An LED lighting up below a brightness threshold, adjustable and free of flicker.
Parts (simulated)
- Arduino UNO board
- Light sensor (LDR)
- 10 kΩ resistor
- 5 mm LED
- 220 Ω resistor
Nothing to buy: every component here is simulated in the browser.
Project steps
- 01Wire the LDR as a divider into the analog input.
- 02Read the raw value and print it on the serial monitor.
- 03Pick a trigger threshold from the measurements.
- 04Add hysteresis so the LED doesn't flicker at the threshold.
What you learn
- Voltage divider
- Analog-to-digital conversion
- Threshold and hysteresis
For teachers
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