Traffic Light Signal With Raspberry Pi

In this blog, you will learn about traffic light signal with Raspberry Pi.

Introduction

In this blog, I am going to explain about the Traffic Light Signal With Raspberry Pi. It will see the time delay in the light and it will see it as the traffic light. I have made a little program to run some LEDs via the GPIO triggered by a push button to do a traffic light sequence.

Parts Of Lists

1. Raspberry Pi
2. LED's
3. Push Button
4. Bread Board
5. Hook up Wires

Traffic Lights

1. Traffic lights, also known as traffic signals, traffic lamps, traffic semaphore, signal lights, stop lights, robots (in South Africa) and (in technical parlance) traffic control signals.
2. The signalling devices are positioned at the road intersections, pedestrian crossings and other locations to control the flow of traffic.
3. The world's first, manually operated gas-lit traffic signal was short lived. Installed in London in December 1868, it exploded less than a month later, injuring or killing its policeman operator.
4. Traffic control started to seem necessary in the late 1890's and Earnest Sirrine from Chicago patented the first automated traffic control system in 1910. It used the words "STOP" and "PROCEED", although neither word lit up.
   
   
   

Traffic Signal Timing

1. Traffic signal timing is the technique where the traffic engineers are required to determine who has the right-of-way at an intersection.
2. Signal timing involves deciding how much green time the traffic lights shall provide at an intersection approach, how long the pedestrian WALK signal should be and many other numerous factors.

Connection for Traffic signal

Take the 3 LEDS for the experiment

1. Led1:GPIO11
2. Led2:GPIO12
3. Led3:GPIO13
4. Connect all the negative pins to the GND.
5. Connect the SD Card with the OS and the data cable.

Programming

#
import time and gpio modules
import time
import RPi.GPIO as GPIO

# set pin 11, 12 and 13 as an outputs

GPIO.setup(11, GPIO.OUT)# red light
GPIO.setup(12, GPIO.OUT)# amber light
GPIO.setup(13, GPIO.OUT)# green light

# set pin 15 as our input
GPIO.setup(15, GPIO.IN)# push button

# set counters at zero
carA = 0
flashA = 0

# set up a
while loop so the program will keep repeating itself indefinately
while True: #call pin 15 button
button = GPIO.input(15)# if button is pressed set carA as 1
if button == False:
    carA = 1

#
if no car detected turn off green and amber lights and# turn on red light
if carA == 0:
    GPIO.output(11, True)
GPIO.output(12, False)
GPIO.output(13, False)

#
if car detected then run through sequence
if carA == 1: #amber light on
GPIO.output(12, True)# wait 5 seconds
time.sleep(5)# turn off red and amber lights
GPIO.output(11, False)
GPIO.output(12, False)# turn on green light
GPIO.output(13, True)# wait 5 second
time.sleep(5)# turn off green light
GPIO.output(13, False)# set while loop to flash amber light 5 times
while flashA < 5: #on, wait 5 seconds
GPIO.output(12, True)
time.sleep(.5)# off wait 5 seconds
GPIO.output(12, False)
time.sleep(.5)# add one to the flash counter
flashA = flashA + 1# reset flash counter
flashA = 0# reset carA
carA = 0

Explanation 

1. In this blog, i have explained about the traffic signal by the correct delay time.
2. The output will be set as the GPIO pin and connect the push button to turnoff all the LEDs when not in use.
3. The traffic signal is very useful for the real time.The operation of traffic signals is currently limited by the data available from traditional point sensors. Point detectors can provide only limited vehicle information at a fixed location.

Output