Inspiration: I currently live in Maryland and also very close to D.C. so speed radars are very common to me. Because there are too many roads and not enough police, speed radars are often used to monitor the general public with the speeds that they are going. However, many of my friends find themselves getting fines despite their insistence that they were not going over 10 mph over the speed limit. Indeed, many people believe that speed radars are not always the most accurate measure as they often rely on ultrasonic sensors which having used ultrasonic sensors myself are not always completely accurate. As someone who themselves have found speed radars and speed traps to be very annoying, I wanted to investigate and determine just how accurate speed radars are and how reliable they can be by doing my best to emulate them.

Project Overview: I wanted to create a mini speed radar that would be able to accurately detect the speed in which a RC car was going. My final project was a mini speed radar that could be used to detect and determine how fast a car is able to move as well as crosscheck that with a given speed threshold and determine whether the car was going below, close to or above the threshold. Based on the speed of the car, a different color LED light would light up(green, yellow, and red) accordingly. In addition to this, I added a photoresistor so that the speed threshold of the system would change in order to more accurately depict the fact that driving faster at night is more dangerous than during the day and wanted my system to adjust accordingly.

Goals: 1.Have a relatively accurate speed radar that could measure speed and crosscheck by personally checking the speed of the car.

  1. Make sure when the car is actually going past a certain threshold that the correct LED lights and buzzer were being outputted. 3.Implement a photo-resistor that would change the speed threshold depending on the amount of light in order to emulate the fact that cars should go slower at night.

Milestone 1: By the first milestone, I had wanted to implement a MVP which could semi accurately measure the speed of an RC car semi accurately by figuring out the optimal setup. This turned out to be the roughest task since I had to be creative about the best way to correctly measure speed.

Final Demo: Have the color of LED light change based on the speed of a model car. Red would indicate that the car has past the speed threshold, yellow would be a warning that the car is approaching the speed limit, and green would mean the car is going in a perfectly safe speed. Afterwards, I implemented the ADC of having the speed threshold change based on a photo-resistor. After testing, I did found that the system correctly adjusted.

Whats next: The most important step to improving the Speed trap project is perhaps thinking about finding a sensor that could adjust the speed threshold based on the weather and figuring out how to have that work in conjunction with the photoresistor. I was considering a humidity sensor. I also did consider creating a LCD or LED Display but had limited time to do so by the end of the project. Finally, I did attempt to emulate the police buzzer noise but found it to be very tricky since the police siren actually very rapidly changes its frequency.

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