Sabertooth+Kagaroo+DC motors as Servos
Step 5 - Power On
Turn of the power and turn on again. That's it!
Now the trick: you can power the EZ-b From the 5v and 0V kangaroo output. Then, connect a digital port (let's say, D0) to S1 on Kangaroo
If you do not want it to be powered from the Kangaroo out, connect ONLY the digital pin to S1.
Do not connect the 5v or the GRound, specially if you are sharing the same battery to both boards, cause that will cause a ground loop and a short!