MPU-9150 + L293D + Arduino Mega, Arduino Gets Stuck!

I have a Arduino Mega 2560 connected to

L293D Motor Driver IC connected to two small size dc motors. MPU-9150 using i2c Xbee v1.1 arduino shield by seeed Li-po battery, 7.4 volts, 2200 mah. all components are tested separately, they all are working fine, the sensor readings showing data on serial monitor, the l293 drives the motors, xbee sends wireless serial data on pc, and li-po is also working fine.

i have checked the wiring alot of times. it all seems to be correct.

the problem arises when i connect all of them together, since i am using a single power source, i power the l293d with the Li-po and the Arduino also with the Li-po.

When the L293D is powered using Li-po and it starts drawing current from the battery, the serial monitor/arduino gets stuck. it doesnt show sensor readings anymore, while the dc motors start spinning. and they continue to spin, until i break connection with the battery.

without the l293d powered, the sensor readings are working fine, everything is going normal, as it should, but as soon as the l293d is connected, arduino is stuck..

i have searched alot of forums for this, found some info, perhaps something to do analog and digital ground? mpu-9150 is digital ground. so that is why it stops the arduino mega as the l293d starts drawing current. all hell breaks loose.

can anybody please help me with this? it is giving me headaches ever since!

I'd say that when motors run, voltage of the battery drops below a cartain level that arduino can't run at. If you are powering your arduino thru VIN pin or the barrel connector, you need > 7V so the voltage regulator can supply enough power. To confirm that, use a volt meter to measure the voltage when motors run .

Here is the breadboard view of the project.

I HAVE changed L293D to L298N arduino shield.

and im using TWO power sources. 9 VOLT battery for Arduino and 7.4V Lipo for L298N.

what could be the problem?

I have attached the breadboard view!