title: I2C bus with battery powered beagleboard
body: <p>I am trying to build a mobile robot (hexapod) using a beagleboard-xm. I have an Arduino nano and two servo drivers connected to the BB-xm over I2C. The Arduino sends the sensor value to the Beagleboard and the servo drivers are used to run the motors. I am trying to get the whole system to run on a single [6V NiMH battery] (<a href="http://www.lynxmotion.com/p-426-60-volt-ni-mh-2800mah-battery-pack.aspx" rel="nofollow">http://www.lynxmotion.com/p-426-60-volt-ni-mh-2800mah-battery-pack.aspx</a>).</p>
  
  <p>When I am trying to just read the sensor values to the beagleboard it works fine but as soon as I start running the whole robot (power on the servo motors too), the sensor values provided by the Arduino over I2C becomes erratic (goes to zero). But when I power the board, Arduino and servo driver from a wall power supply everything works fine. So I am pretty confident that the issue is with the current being supplied by the battery to the whole system when the motors are running, but I am not sure why this is happening. The battery can supply a maximum of 28A and the servos together do not use more than 20A (18 servos).</p>
  
  <p>So, I guess my question is whether my understanding is correct or is there is any other reason for this?</p>