Arduino Resets Upon Bluetooth Communication

i've been having trouble bluetooth project. when have arduino uno powered via usb can send value servo turn on bluetooth no problem. however, when detach usb , connect 9 volt battery power jack arduino resets every time send data on bluetooth (using serial monitor). know how fix this?

sounds have current sourcing issue.

fresher battery?
6 x aa?
wallwart?

Arduino Forum > Using Arduino > Networking, Protocols, and Devices (Moderator: fabioc84) > Arduino Resets Upon Bluetooth Communication

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