Street lights burn full power all night on roads that are empty for most of it, and when one fails nobody knows until somebody complains. This project addresses both: an ambient light sensor with proper hysteresis switches the string on at dusk, the lamps run at a reduced level until a vehicle or pedestrian is detected and then brighten for a hold period, and per-pole current sensing detects a lamp that has failed and reports which pole it is. The energy saving is calculated from a stated duty profile and then measured, rather than quoted from another report.
Not just the parts. Teams budget from a component list, then run out in week six on wire, connectors and the driver board they destroyed. These are the lines that catch them.
| Line | Cost |
|---|---|
Components and materials From the bill of materials | Rs 4,410 to Rs 13,650 |
Spares and replacements 15 % — you will destroy something | Rs 662 to Rs 2,048 |
Consumables and hardware Wire, connectors, headers, screws, heatshrink | Rs 529 to Rs 1,638 |
Perfboard and assembly | Rs 150 to Rs 400 |
Report, printing and binding Two or three bound copies, plots and the plagiarism check | Rs 400 to Rs 1,200 |
| Total | Rs 6,151 to Rs 18,936 |
| Each, split 3 ways | Rs 2,050 to Rs 6,312 |
Indicative bands last checked in August 2026 — a guide, not a quotation. Prices move and vary by seller, and anything you can borrow from the lab comes straight off the total. The 2.6 week figure assumes 6 person-weeks of work shared between 3; students past 4 add coordination rather than output, so the estimate stops improving there.
The same chain in words
The ambient light sensor decides day from night. A hysteresis band separates the switch-on and switch-off thresholds so a passing cloud or a car headlight cannot make the string chatter at dusk.
At night the lamps default to a reduced dimming level rather than off, because a road with no light at all is not a saving, it is a hazard.
When a presence sensor triggers, that pole and its neighbours ramp to full output and hold for a set period after the last detection, so a vehicle travels inside a moving pool of full light.
Each pole's driver current is measured. A lamp that has failed draws no current while commanded on, which is reported to the dashboard with the pole identity.
Everything is logged, so the results chapter can compare measured consumption against a conventional always-on installation over the same nights.
This is the chapter that separates an engineering project from an assembly job. Every value below carries the formula that produced it and the assumptions it rests on — check them against your own ratings before you use them, because your motor is not this motor.
Energy = sum over each level of (power at that level x hours at it)
A 100 W luminaire over a 12 hour night: conventional is 1200 Wh. Adaptive at 30 percent output for 9.6 hours is 288 Wh, plus 2.4 hours at full is 240 Wh, giving 528 Wh. The saving depends entirely on the assumed traffic fraction, so state it and then measure the real one.
Set by the lighting class the road must still meet
This is not a free choice. Adaptive lighting standards allow the lighting class to be lowered when traffic volume falls, but not removed. Cite the class you are designing to rather than picking a percentage that looks good in the savings table.
Separate switch-on and switch-off thresholds
Without a gap the string oscillates around the threshold at dawn and dusk, which is hard on the drivers and looks broken. A confirmation delay of a minute or two on top removes the effect of a passing headlight entirely.
Long enough to cover the pole spacing at road speed
At 40 km/h a vehicle covers 11 m per second, so a 30 m pole spacing is crossed in under three seconds. The hold time exists so the lamp does not drop back to dim between vehicles in light traffic, and so a pedestrian walking is not left in the dark.
PWM dimming at a frequency above the flicker threshold
Low-frequency PWM dimming produces stroboscopic effects that are dangerous around moving machinery and unpleasant on a road. Analogue dimming avoids it entirely at the cost of slightly lower driver efficiency at low output.
Compare measured driver current against the commanded level
This is what makes the project worth more than a dimming controller. Detecting the fault is easy; deciding it is a real fault and not a momentary dip, and reporting it with the right pole identity, is the actual engineering.
| Item | Qty | Unit cost |
|---|---|---|
LED luminaires Small dimmable LED modules standing in for street luminaires | 4 | Rs 250 to Rs 900 |
LED drivers Constant current with PWM or 0-10 V dimming input | 4 | Rs 250 to Rs 800 |
Microcontroller board ESP32 with WiFi | 1 | Rs 350 to Rs 750 |
Ambient light sensor BH1750 digital lux sensor, or an LDR with a divider | 1 | Rs 80 to Rs 300 |
Presence sensors IR break beam pairs or HC-SR501 PIR modules | 4 | Rs 70 to Rs 250 |
Current sensing INA219 module per pole, or a multiplexed shunt | 4 | Rs 150 to Rs 400 |
Power supply 12 V or 24 V SMPS sized for all four luminaires | 1 | Rs 350 to Rs 900 |
Model road base Board, printed road, pole mounts | 1 | Rs 500 to Rs 1,600 |
Enclosure and wiring ABS box, terminal blocks, cable | 1 | Rs 250 to Rs 700 |
Specifications are written as ratings rather than brands, so any equivalent part works. Where a line says to borrow from the lab, do — it is usually the largest number on the page, and the total drops to Rs 6,151 at the low end without them.
None of these blocks you — they are learnable inside a semester. Each one you do not have costs a couple of weeks, so count them into your plan.
Anything marked required is a blocker, not a difficulty. Arrange the access before you commit to the project, not after.
Use these when your guide says the scope is too small, or when you want something in the results chapter that nobody else in your batch will have.
The structure below is what a project report is marked against, with the mistake that costs marks in each chapter. There is no template to download and there will not be one: the writing is your work, and a site that did it for you would be helping you cheat rather than helping you pass.
A diploma report is typically 40 to 60 pages. The design and results chapters carry the marks; the literature survey can be short. A mini project report runs to about 40 to 50 pages, and the literature survey is usually brief. Guides expect one clear objective, met and measured.
The full report guide — front matter, conventions and page countsOne paragraph covering what the problem is, what you built, and what the result was. Written last, even though it appears first.
Loses marks: Describing the problem and the method but never stating a result. If there is no number in your abstract, it is not finished.
Why the problem matters, the context it sits in, and a clear statement of the objectives your project set out to meet.
Loses marks: Objectives written so vaguely that nobody can tell at the end whether they were met. Write objectives you can tick off in the conclusion.
What has already been done, what each approach achieved, and the specific gap your work addresses.
Loses marks: A list of paper summaries with no comparison and no gap. The survey exists to justify your design choice, so end it by saying what you chose and why.
The system as a whole: the block diagram, what each block does, and the signal or power path between them.
Loses marks: A block diagram copied from a datasheet or another report. Draw yours to match what you actually built, including the parts that are inconvenient.
Every component value and rating, with the formula, the assumptions and the arithmetic that produced it. This is the chapter that distinguishes an engineering project from an assembly job.
Loses marks: Component values with no justification. If a resistor is 10 kOhm, the report must say why it is not 1 kOhm.
The circuit as built, the PCB or wiring, the flowchart, and the parts of the code that carry the actual logic.
Loses marks: Twenty pages of pasted source listing. Include the flowchart and the few functions that matter, and put the full listing in an appendix.
What you measured, in tables and graphs, compared against what you predicted in the design chapter — including where they disagreed.
Loses marks: Photographs of the working model presented as results. A photograph is evidence that it exists, not evidence that it works. Results are measurements.
Whether each objective was met, what the measured performance was, and what the honest next step would be.
Loses marks: Future scope written as a wish list of unrelated features. It should follow from a limitation you actually hit.
Every source in a consistent style, plus datasheets, full code listings and the complete bill of materials.
Loses marks: Citing a blog or a video where a datasheet or a standard exists. Cite the primary source for anything you relied on.
The demonstration is half the assessment. These are the questions this project invites, and the answers are written the way you would give them out loud.
Because ambient light hovers around the threshold for a long time at dusk and dawn, and any noise, cloud or passing headlight pushes it back and forth. With a single threshold the lamps switch on and off repeatedly. Using a lower level to switch on than to switch off means the system has to move a definite amount before it changes state, and a confirmation delay removes brief disturbances entirely.
Because street lighting exists for safety, including for pedestrians and cyclists that the sensors may not detect, and a road that goes completely dark between cars is more dangerous than one that is uniformly lit. Standards for adaptive lighting allow the lighting class to be reduced when traffic falls, not suspended. Dimming captures most of the saving while keeping the road lit.
By comparing the current the driver is drawing against the level it was commanded to. A working lamp at 30 percent draws a predictable current; a failed lamp draws essentially none while still being commanded on. The controller confirms the condition over several readings before reporting it, so a momentary dip is not treated as a failure.
Because PWM dims by switching the LED fully on and off rapidly, and if that rate is low enough to be perceived it shows as flicker. Worse, it produces stroboscopic effects that make moving objects appear stationary or to move oddly, which is a genuine hazard near roads and machinery. Keeping the frequency well above the perception threshold, or using analogue dimming, avoids it.
From the hours spent at reduced output, which for most roads is the great majority of the night. The saving is the difference between the power-hours of a fixed installation and the sum of power times hours at each level of the adaptive one. It depends almost entirely on the traffic profile, so a saving figure without the assumed traffic fraction attached to it means nothing.
Normally taken as a Diploma project (C-20, 6th sem) or B.E. mini project (5th/6th sem) project. If yours is a different course, the extensions above scope it up and the simpler half of the design scopes it down — the arithmetic does not change. Back to all projects.