I have GPIO channels in my controller.
The controller manufacturer does not know exact number of drive strength of the GPIOs.
The controller is a digital signal processor (DSP) board. I want to control a stepper motor using my GPOIs, but the input of stepper motor driver has specific requiremen t(input voltage and input current.) If the input current of the stepper motor driver is higher than GPIO's drive strength, the GPIO may be damaged.
Is there a simple circuit to test GPIO drive strength using an oscilloscope without damaging the GPIO?
----I figured it out that GPIO strenght test circuit was not a good idea. The DSP controller is kind of custom-made one, and only several tens were produced. I contacted one of the DSP controller users and found that the GPIOs have enough drive strength for my stepper motor inputs. I prefer the opto-isolator type connection since it does not share ground and noise