I was measuring the AUX outputs on a Cube Black (and also Blue) using an oscilloscope, and noticed that for both PWM and Dshot, there is a slow transient rise on the ports. As I found from measuring a PWM signal, it takes a signal around 2 microseconds to reach 3.3V on the AUX ports, and under .2 microseconds on the MAIN ports. This causes problems with the Dshot protocol, because it is very fast and therefore the signal does not have time to reach 3.3V, as shown in the picture below:
Some Dshot ESC’s need a solid 3.3V input to work properly, and I have seen shaky behavior on ESC’s that I believe can be attributed to this.
Is this a known/documented issue? I tested a Pixhawk 4 and it does not have the same delay, but I need to run 6 DSHOT outputs while fmuv5 boards only support 4.
Are there types of Cubes that do not have this behavior?