So there's no Arduino ready code for the servo?
If I got it right, if you connect it like normal servo, you get a continuous servo, where you control its rotation speed and direction. To make it rotate to a given angle, you need your own function:
The function gets the desired angle, then:
- read the present angle
- decide whether to rotate clocwise or counterclockwise
- start rotating, continuously reading the angle
- stop when the desired angle is reached, perhaps slowing down when near
It's strange that the feedback signal is an analog PWM. You have to actually measure the length of the pulse. I guess that's done with an interrupt handler. An interrupt is launched when a pin change occurs. If it goes high, the current µs is read. If it goes low, the last read µs is subtracted from the current µs time and saved to a global variable. No need to calculate the actual angle in the interrupt routine. Only when you need to know the angle, you calculate it from the global variable.