Hi fellow Arduino hackers,
I have a project in mind for which I need some guidance. My project is to create a LED heart that shows an 'beating' animation where the animation would get faster and faster as a person approaches it. And it would get slower and slower as a person goes farther and farther away. After a certain critical distance, the heart would drop to it's natural beat (which I can program to be 72 beats per minute).
Example: Beyond 5 feet, I want it to beat at a constant rate of 72 beats per minute. Within 5 feet I want the beating to get faster if I (of my girlfriend) approach it and slower if I (or my girlfriend) go away from it.
(Yes you guessed it right, this is for my girlfriend as a Valentine's day present
I will be using this heart LED kit from: http://jimmieprodgers.com/kits/openheart/
But my main question is regarding the sensor. I want a sensor which would meet the following requirements, in order of decreasing importance.
0. Be not a high drain on power.
1. Be reasonably priced.
2. Be omnidirectional.
3. Be reasonably accurate in measuring the distance. Since I am not using it in a robot for object avoidance, I can tolerate a little bit of inaccuracy.
4. Responds only to human proximity. I don't want it to respond to non-animate objects, like closing doors etc.
I did some googling and I think this sensor meets requirements 1 and 3: http://www.amazon.com/Vivotech-Ultrasonic-Distance-Measuring-Compatible/dp/B0089VA3AY/ref=sr_1_1?ie=UTF8&qid=1391214324&sr=8-1&keywords=arduino+distance+sensor
But I am not sure how it will perform with regards to power.
It would still get triggered by doors and non-human objects, right? Plus it would be very directional, am I right? I think I can accept a sensor which will work for non-living objects, because most likely the gift won't be placed next to a moving door. So I am willing to compromise on requirement 4 if it comes to that. But the rest of them (1-3) are pretty darn important.
Can anyone tell me if I can achieve all my goals using a IR sensor or if I can achieve most of my goals using an ultrasonic sensor only?
Thanks in advance,