What you build
A model street-light system with an Arduino. Lights switch on automatically at dusk using a light sensor, dim when no movement is detected, and a current check reports any lamp that has failed.
Modules
- Light sensor for dusk and dawn switching
- Motion sensor for dimming
- Lamp failure detection by current sensing
- Fault indication on an LCD or buzzer
What you will understand
- Reading analog and digital sensors
- PWM for dimming LEDs
- How energy is saved by dimming
How it is tested
- Tests at different light levels and with a lamp removed
- Measured energy saving compared with always-on lights
What goes in the report
- Block diagram and circuit
- Program flowchart
- Test results and energy-saving calculation
Viva questions to prepare
- How does the LDR decide it is dark?
- What is PWM?
- How does the system know a lamp has failed?