I am assembling an ice tube kit. In the "design" section there are small schematics of different sub assemblies of the kit. I cannot find a reference to R5 and C7 and how these discrete components relate to the functioning of the kit.
I'm not an electronics whiz, but C7 seems to be a capacitor to ensure sufficient power is available for the inductor pulses. And R5 is a pull-down for base of the boost-control transistor, ensuring that current will not flow through the inductor unless the ATmega outputs +5v on BOOST (PD6).