Introduction: Bike Alert
This morning, while riding my bike, I thought, "Wouldn't it be nice to know when someone is approaching from behind?" I didn't want to use mirrors or funny glasses, so I decided to use an ultrasonic transducer to trigger a buzzer when approached.
This involves a Ping transducer, Arduino, buzzer, switch, 9 volt battery and enclosure.
Thanks to the world of 3D printing, these things don't have to be force fit into a black box anymore.
For the design and print files of the box (created in Autodesk's 123d software--free):
http://www.thingiverse.com/thing:115074
Step 1:
I started by piling the major components together to see what sort of space it would take.
Step 2:
I followed by creating a box--sort of banana shaped instead of rectangular.
Step 3:
I added the transducer, buzzer and switch. I didn't get my spacing quite right on the transducer, so I just fit one of the elements into one of the box holes.
Step 4:
Here is the code for the Arduino:
const int pingPin=7;
long duration;
const int buzzer=3;
void setup()
{pinMode(buzzer,OUTPUT);
}
void loop()
{pinMode (pingPin, OUTPUT);
digitalWrite (pingPin, LOW);
delayMicroseconds (2);
digitalWrite (pingPin, HIGH);
delayMicroseconds (5);
digitalWrite (pingPin, LOW);
pinMode (pingPin, INPUT);
duration = pulseIn (pingPin, HIGH);
if (duration > 12000 and duration < 20000)
{digitalWrite (buzzer, HIGH);
delay(2000);
digitalWrite (buzzer, LOW);
delay(1000);
}
else
{digitalWrite(buzzer,LOW);
}}
Step 5:
Connect everything together and close the lid with a wood screw.
Step 6:
Secure to your bike in whatever way is appropriate--I use velcro.

Participated in the
Bikes and Wheels Contest

Participated in the
3D Printing Contest
3 Comments
10 years ago on Introduction
When I am ready you will be the 1st to know my friend ! Until then I will keep learning from the Pro's !
Build_it_Bob
10 years ago on Step 6
Great idea Mike ! I like your custom enclosure too ...you are the man with the 3d printer!
I always enjoy your creative projects ...keep them coming and many thanks for sharing.
Build_it_Bob
Reply 10 years ago on Introduction
Thank you! They have some really cool prizes in the "Bikes and Wheels" contest, so I thought I'd give it a shot.
Hopefully, you can document and publish a project one of these days :)