National FAQ: Can we use Arduino? (section: 1 / paragraph: / sub-paragraph: / line: 1)
A: No. Arduino microcontrollers have electrical and electronic components beyond those allowed in the list in rule 3.e.
National FAQ: Can a small diode (lights on/off) with a resistor be used? The diode will turn on when an electrical switch is pressed, and turns off when the switch is off. (section: 3 / paragraph: e / sub-paragraph: / line: 2)
A: No. Diodes (a semiconductor device) are not listed in the allowable electrical components in rule 3.e.
National FAQ: Can a "battery pack" be formed by wiring AA batteries in series and simply wrapping them as long as the labels of individual AA batteries are clearly visible? (section: 3 / paragraph: b / sub-paragraph: / line: 2)
A: If you are asking whether you can wire the 8 AA 1.5 V batteries in series or parallel or a combination of both, nothing in the rules says you cannot. So yes, you can make your own battery pack, as long as the vehicle has no more than a total of 8 AA batteries and all of their labels that say "AA 1.5 V" is clearly visible.