Sounds like a good idea. I'll get another TIP120 and try a different pin on the Uno to drive the base. I don't have another Uno handy, and this one works fine with the exception of this particular scenario, so hopefully that's not the root cause.
Sounds like a good idea. I'll get another TIP120 and try a different pin on the Uno to drive the base. I don't have another Uno handy, and this one works fine with the exception of this particular scenario, so hopefully that's not the root cause.