Embedded systems · Microcontrollers
Energy Saving Street Light
- At a glance
- Embedded controller targeting at least 25% energy saving: light-triggered switching, forced 1–5 AM switch-off, daylight-saving and solar-noon clock correction
- Methods
- Microcontroller firmware, interrupts, comparators, timers
What?
While street lights are becoming increasingly automated and can react to outdoor lighting conditions, they are still considered to consume excessive energy resources. Several councils in the UK have trialled a scheme to switch off lights during the early hours of the morning when few people are on the streets. This project aims to design and develop an embedded system for a smart energy saving street light which can reduce energy expenditure by a minimum of about 25%.
How?
The system has four functions:
- Automatic light toggling. A transition from light to dark or vice versa triggers a high priority interrupt. A rising edge in voltage detected by the inbuilt comparator toggles the light off; a negative edge toggles it on.
- Switch off between 1 and 5 AM. The program keeps tabs on the microcontroller timer and forces the light off between 1 AM and 5 AM regardless of ambient light.
- Daylight saving time adjustment. The clock goes forward an hour on the last Sunday of March and back on the last Sunday of October.
- Daily time adjustment to stay in sync with the sun. The system records sunrise and sunset times and calculates solar noon, which must coincide with noon on the timer, applying a daily correction for any discrepancy.
Result
Video demonstrations of each function: