when i apply power with gpio 2 connected to the control wire of a futaba s3003, both the red and blue LEDs stay lit, and the servo makes a chugging sound. if i pull gpio 2 low with a 10k resistor, the lights do the same thing. with gpio 2 floating or high, it boots normally.
once booted, i can connect the servo and control it without problems. so i think that rules out any sort of power stability issues caused by the draw from the servo (i have a 10uF cap before my 3.3v regulator and a 100uF cap after)?
i feel like i saw a table somewhere showing that gpio 2 affects the boot loader, but i can't find it now. if it does, and i need to keep it high/floating when powering on, how can i do this (my electronics knowledge isn't very deep)? can i use a diode or transistor to prevent the servo control wire from influencing the gpio pin? or maybe a pull-up resistor to keep it high until driven?
any ideas are appreciated!