Published December 9, 2024

Bicycle Safety System - Lane Tech PCL

A Particle photon 2 is used in order to add a motion activated electronic horn and a motion-activated light to my bicycle.

IntermediateFull instructions provided49

Things used in this project

Hardware components

Ultrasonic Sensor - HC-SR04 (Generic)

Relay Breakout Module 5V

Apple iPhone

Hornit dB140 Bike Horn V3

1200 Lumen Bike Light - Red

SG51R Micro Servo

Particle Photon 2

Software apps and online services

Pushover

Hand tools and fabrication machines

Soldering iron (generic)

Story

This project was a part of the Home Automation assignment in the Lane Tech PCL course.

Summary

I wanted to be able to toggle an electronic bike horn and bike light on/off with a distance sensor, and be able to detect when cars were approaching my bike from behind. I also wanted a notification to be sent to my phone to indicate when a car was approaching. This allows me to be a safer bicyclist, as I will hear the audio cue from my horn, the car will see and hear the light and horn, and I will see the notification on my phone.

Procedure

DistanceSensor

I started by figuring out how to work with the distance sensor. I did this by making a simple circuit that had an LED light up when there was an object within 10 centimeters of the sensor. After setting my only sensor up, I moved on to the physical components of my project.

BikeLight

I needed a way to control the bicycle light that I already owned. To do this, I decided to use a servo to physically push the button-- I didn't want to permanently modify the light, so a servo was the clear choice. I attached a servo to the light with hot glue, and removed the silicone end cap over the button on the light to make pressing it more consistent.

BikeHorn

With the light set up, I then started working on the horn. The horn had a detachable trigger, as shown in the image below.

Horn Trigger

As my bicycle horn was already broken, I was comfortable with trying to salvage it for the project. When I plugged in the trigger initially, the horn would turn on and the button would not have any functionality for toggling the horn on or off.

I observed that the problem was likely due to a kink in the cable. I removed the plastic around the button, and saw that the button was just connecting the two cables in the detachable trigger.

Disassembled Button

With this in mind, I cut the cable of the horn trigger before the kink, and stripped the wire. I then soldered two wires to each cable.

In order to control the horn with my photon, I decided to use a relay. This allowed me to flip a switch electronically to connect the wires and disconnect them, turning the horn on and off.

Horn with relay

NotificationstoPhone

I utilized the pushover app as the particle community integration docs has instructions for integration with the photon.

Code

Bike Light/Horn/Notifications

#include "Particle.h"

SYSTEM_MODE(AUTOMATIC);
int echo = 1; //PWM pin needed?
int trig = 5;
int horn = 9;
long duration;
int distance;
int brightness;
Servo backServo;
SerialLogHandler logHandler(LOG_LEVEL_INFO);

void setup() {
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  pinMode(horn, OUTPUT);
  Serial.begin(9600);
  pinMode(A2, OUTPUT);
  pinMode(0, INPUT);
  backServo.attach(A2);
  backServo.write(10);
  
}

void turnOnBack(){
    backServo.write(120);
    delay(250);
    backServo.write(10);
}

void turnOffBack()
{
    backServo.write(120);
    delay(2000);
    backServo.write(10);
}
void loop() {
    digitalWrite(trig, HIGH);
    delayMicroseconds(10);
    digitalWrite(trig, LOW);
    
    //read echo pin after triggering
    duration = pulseIn(echo, HIGH); //read up on pulsein
    distance = duration * 0.034 / 2; //speed of sound wave, then divide by 2
    
    Serial.println(String(distance) + "cm");
    
    if(distance < 2000) //some issues w/ longer distances
    {
        digitalWrite(horn, HIGH);
        turnOnBack();
        Particle.publish("notification", "CAR BEHIND YOU!!!!!!!");
        delay(4000);
        digitalWrite(horn, LOW);
        delay(2000);
        turnOffBack();
        delay(1000);
    }
    else{
        digitalWrite(horn, LOW);
        delay(250);
    }
  
  
}

Credits

Nate

2 projects • 0 followers

Bicycle Safety System - Lane Tech PCL

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Summary

Procedure

Schematics

Diagram

Code

Bike Light/Horn/Notifications

Credits

Nate

Comments

Embed the widget on your own site

Bicycle Safety System - Lane Tech PCL

Bicycle Safety System - Lane Tech PCL

Things used in this project

Hardware components

Software apps and online services

Hand tools and fabrication machines

Story

Summary

Procedure

Schematics

Diagram

Code

Bike Light/Horn/Notifications

Credits

Nate

Comments

Related channels and tags