I am using Trinket Pro 5V to run a simple i/o code. The input from the piezo vibration sensor is read by the Trinket and Translated into a servo position. It works fine powered through a USB connection, however as soon as I try to power it using a 9V battery (plugged into the Bat+ and G terminals), the code stops running and the red light on the Trinket starts to blink.

Is the power source not sufficient - 9V?

Has anyone faced a similar problem?