Provide an example of the wave going in the other direction

[devraj]

First of all thank you so much for putting this example together and sharing it for reference.

I wanted to lodge this issue to provide an example of the wave pattern going the other way (to complete the cycle of the poor man's demo of the contacts being sent as opposed to be received).

For completeness it would be cool to have a setting which reverses the wave in the demo application.

I intend to fork this and provide a pull request.