Final Project
FINAL: TRAFFIC SYSTEM
Final Project Proposal:
Traffic system at a crossing
·Two traffic lights
·Two motor cars
·Two Pulleys
·A board
July 2nd
I made a traffic light on the protoboard on last week. On this week, I construct a traffic light for the prototyping and transplant the circuit on it. Also, I program the Arduino of the circuit so that the different LED of different colors will shine in turns. Now it’s a real traffic light.
Here you could DOWNLOAD the program.
July 5th
I made one of the cars in my traffic system by sawing, drilling, and laser cutting. The wheels were cut from the wood board by laser cutter. I plan to let the car move by connecting it with a pulley. In addition to, I changed the Arduino in my circuit from UNO to NANO and soldered the NANO. I did this because NANO is smaller so that I could combine it with the traffic light model more easily.
July 11th
I’m thinking about how to start up my car and use what as a trigger. After comparing, I decide to use the photo transistor. The principle is that attaching the photo transistor in the same series as the DC Motor and attach a infra red LED in the series next to it. When the infra red LED shine and the photo transistor detects enough infra red light, the photo transistor will allow current to flow through the series to power the motor. And when it doesn’t detect the infra red light, it won’t allow current to go through so that the motor cannot work. I make a test with the blue LED as the replacement of motor on this week. You can see that when the green LED is shining, the blue LED is shining simultaneously.
July 18th
Although I had a successful test with the LED for the trigger on the last week, I failed when I replaced the blue LED with the DC motor. It actually worked but the voltage was not high enough to power the motor. After consulting Rob, I attach the photo transistor and the DC motor in different series because the current in the series of photo transistor is too low to power the DC motor. Affter DC motor is attached to a different series, the serires will offer enough voltage to run the motor. I program the Arduino so that it knows when it should send a signal to the pin of motor to change its state to HIGH. Whether sending the signal or not depends on the reading of the AnalogRead. It will send the signal only when the reading is higher than 500.
July 23rd
I solve the problems of multi-tasking and the power for the car this week. You can see that there are two Arduinos in my lask week project because I didn’t know how to run two loops simultaneously. After discussing with Nathan, I renew the program this week and combine the two circuits togther. Fortunately, it works. For the power for the car, I think using the pulley to pull the car is the safest plan. The car won’t go into wrong direction or start up at wrong time for this plan.
Multi-tasking:
Here you could DOWNLOAD the program.
Pulley:
July 29th
Although I found the appropriate DC motor last week, I didn’t attach it in to circuit. But when I attach it into the circuit today, I find that it’s not working anymore. The Probelm is that the Arduino cannot offer enough voltage to operate such powerful motor. The thing I need to do is to add a transistor in my circuit so that it will magnify the signal of the circui and then the DC motor can rotate. I still make some mistakes when I add the transistor in the circuit because it has three legs. As a result, you need to be really careful about which leg attaches to which hole of Arduino. If you are also confused, visit this WEBSITE.
July 31st
There are only two lab times available before the final presentation, and I make some progress today. My final project is to build a tranfic system at a crossing, which means that I should have two traffic lights and two cars which need two triggering system. As a result, I cut the elements of the construction of traffic light today. Also, I build another circuit for photo transistor just as the same I built before. So I do both very successfully for laser cutting and circuit. And you can download the elements of my construction below.
Also, I meet a problem when I try to attach my infra red LED with the Green LED in parallel in the circuit. Initially, when I attach the infra red LED into the circuit, it’s working but it turns off the Green LED. Nathan and I both have no idea about that problem, but he reminds me that I should to pay attention to whether it causes shortage in the circuit. Later I try to add a resistor with the infra red LED and the problem is solved. The problem is that the resistance of the nifra red LED is too low so that when you attach it with other elements in the circuit in parallel, it’s really easy to cause shortage in the circuit. Fortunately, I find it and solve it.
August 3rd & 4th
For weekend lab time, I commence the car part in my final project. I though I gonna make them with wood before, but later I found that making them by hand is not very precise, which will affect the motion of the car. As a result, I decide to build their model to 3D print them. For my cars, I only need them to be just rough toy cars, so it’s not difficult to build the their models. Later, I 3D print it and make a test for the pulley. Fortunately, it works well!
MODEL IN CURA
DOWNLOAD the body model of the car in Fusion 360
DOWNLOAD the wheel model of the car in Fusion 360
Project
August 5th
From the post on Aug 3rd & 4th, you can see that I reserved a hole for the thread of the pulley in every car, but later I realized that the two threads will tie together at the crossing. With Rob’s help, I change from pulley to magnet. The principle behind it is when you add a cardboard between the two magnet, they will still attract each other, so when one of them is pulled by the motor, the other one will follow this one. You can see from the video below:
Principle
Later, I joined the traffic light and the motor with the car to build a simple traffic system. And I tied the magnet under the cardboard with the thread so that I could use the motor to pull it back. When it was pulling back, the car was moving forward because the magnet on the car was attracted by the magnet beneath the cardboard.
August 7th
Today I almost finished the construction of my final project. I met some problems because of the huge volume of my project, and it almost be killed by accidently falling down, but I still successfully fixed and continued constructing it. At the end, I made a test with one car and polished my project’s details.
August 8th
This is the last course of my class, and I finally finished all the constructions and tests for my final project. The upper face of my project seems to be bery simple because there are just two traffic lights and two cars. However, the most sophisticated things are all beneath the surface. You can see that in the images. I was so satisfied that I could learn so much things in this summer and find the career that I really interested in. I hope you all love my final project!
