I need to figure out how to make the connection with L293D and arduino and a separate power supply
I'm not sure if that's feasible....
The 293 does two main things:
- It switches a dc or stepper motor's relatively high (say 12+) voltage with a logic level voltage (5)... that's unnecessary on a servo, since the high voltage goes straight into the servo in the first place and doesn't need switching
- It provides direction to the dc or stepper motor by controlling which motor input is + or -... that's also unnecessary on a servo, because that's basically what the pulse on the yellow line does.
If you have a look at a 293 data sheet, it makes no mention of using it to drive a servo- it mentions dc and steppers as specific purposes, though