Ultrasound Based Tail Light for Bike
by ramyaasakthi in Circuits > Arduino
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Ultrasound Based Tail Light for Bike
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First Instructable. The idea is simple wanted to make a flashing tail light for my e-bike, to make it more interesting wanted to make it flash faster as vehicles comer to the bike.
Supplies
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Arduino Micro.
Soldering Iron and Supplies.
Wires.
LED - I'm using 5 Red, 5mm LEDs
Transistor 2N2222
Resistor 220R
Ultrasonic Sensor, HC-SR04
Zip Ties - (I decided to use this to mount the light to the bike)
M2 screws and lock nut (To hold the case)
Power supply, I'm building this for my e-bike will be plugging into the controllers 5V directly.
A 3D Printer, Maybe.
Wild Run
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Connections are straight forward,
Ultrasonic Sensor
ECHO pin -> Arduino 2
TRIGGER Pin -> Arduino 3
Vcc -> 5V
Gnd -> Gnd
Code.
#define echoPin 2 #define trigPin 3 #define LEDPin 12 long duration; void setup() { pinMode(trigPin,OUTPUT); pinMode(echoPin,INPUT); pinMode(LEDPin,OUTPUT); } void loop() {digitalWrite(trigPin,LOW); delayMicroseconds(2); digitalWrite(trigPin,HIGH); delayMicroseconds(10); digitalWrite(trigPin,LOW); duration=pulseIn(echoPin, HIGH); int distance=duration*0.034/2; //Serial.println(distance); int LED_time=map(distance,100,600,100,1000); //Play with values here. flash(LED_time); } void flash(int flash_time) { digitalWrite(LEDPin, HIGH); delay(flash_time); digitalWrite(LEDPin, LOW); delay(flash_time); }
For a quick check to see if things work, Just hooked up the sensor to an Arduino Mega, and tried to flash the builtin LED and Voila.
The Enclosure
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As mentioned earlier, the light is going to be mounted using zip ties. I use fusion 360 for this. A couple of sketches in fusion and the model is done.
The enclosure is actually 3parts secured together using M2 screws,
Attached STL files.
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Went forward and started to print the case, unfortunate that the extruder stepper got fired.
Have ordered a new motor and it, without the enclosure the soldering couldn't be done. Waiting for the new Stepper to arrive.