Motion Detection

Components & Accessories LEDs
1

I have searched through SparkFun products and the internet for a suitable device for a project of mine. As yet I can’t seem to find a suitable affordable product.

I am trying to build a swimming stroke counter. this is in an endless pool where you swim against a current, so your body stays in the same position. My goal is to count every time your arm comes out of the water when swimming front crawl.

I have tried an IR emitter/receiver but the arm is insufficient to clearly break the beam. So I am looking for more of a narrow beam such as a laser and a laser receiver.

This is where I need help does anyone know of a device I could use. The pool is 2.5 Metres wide so i need a transmitter and receiver that I can place on either side of the pool.

Any ideas would be welcome and I thank you all for your help

Regards Dave_A

2

A cheap laser pointer would work for a transmitter. In a pinch you could probably get away with a bright LED and some lenses to make a tight beam. For a receiver, a [photocell inside a tube would work. (The tube is to keep ambient light away from the photocell and only let in the beam you’re breaking.)

If you put a bicycle reflector on the other side of the pool, you could mount the laser and photocell together on the other side. Then you don’t need to run wires all the way over to the other side for a receiver.](Mini Photocell - SEN-09088 - SparkFun Electronics)

3

thanks for the idea, I’ll have a look into that