Arduino resets periodically while being powered via an external power supply.
I am using an 5V Arduino Mini (https://www.sparkfun.com/products/11113). While the Arduino is plugged into the 5v USB power coming from my computer it runs as expected (the lights flash in the right order and with the right timing, it accepts code etc.), but when it is powered through a regulated power supply it will turn on for a few seconds, then restart, run for a few more seconds, restart and repeat this indefinitely. I am programming it via an FTDI programmer (https://www.sparkfun.com/products/9716), and using two Polymer Lithium Ion Batteries (https://www.sparkfun.com/products/8483) wired in series to get it up to the necessary voltage. I have tried disabling auto reset via bridging 120 ohms equivalent resistance between RST and VCC and connecting a 10 micro-farad capacitor to RST and GND, but that did not solve the problem. I am fairly certain there are no problems with the code, because it runs perfectly when plugged into the computer, and I get the problem when running any code.
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