Background, I am building a prototype that has an internal circuit board controlling RGB LEDs. Due to size restrictions on the actual prototype I have to use the Pro Mini 5V board to install in the casing. Also, I need to power the board with a series of to 3V batteries (for a total of 6V) instead of the 5V supply from the USB.
I did all of the intial circuit building and programming with an UNO board. I tested the UNO circuit with both the USB 5V supply and the exact 6V battery supply that I am using. Everything works perfectly. I soldered up the circuit and components completely on the Pro Mini 5V board. I tested it with the USB 5V supply attached to the computer and it works perfectly. However, when I attach the 6V battery supply it will not work. Each time I press the button in the circuit the board seems to reset.
Any thoughts or help?
My initial assumption is that the Pro Mini 5V can not handle the 6V supply and resets to protect itself. Any help is greatly appreciated.