Two 6500 Sonar Module Trouble I've installed two 6500 sonar modules on HB.
And they operated for a good while. But my HB got some electric shock,
and the shock was remedied by downloading pcode. But after then, 
sonar modules have some trouble. In short, 1 sonar module works well.
But when I connect 2 modules to HB power port simultaneously, sonar_sample() 
function returns always 620~670, impractical value.

Does anybody know the reason? How can I make them work together? 
Would I need another power supply?

Thanks.
