I have a reasonable working knowledge of electronics but am trying to find a solution to a puzzle I've come across and have not been able to find a complete answer. This involves a stepper motor and I have not worked with these before, but understand their principle.
I am trying to drive a stepper motor in the following manner. I have an encoder that is running constantly and generating a frequency that is approximately constant. This will drive my motor at a speed proportional to the encoder output frequency. I want to start the stepper motor on a signal from a sensor and stop it on a signal from a second sensor.
I've found details of how to drive a stepper motor, using ICs such as the UCN5804 series.
I've found material on the need to apply ramping to the speed of the motor on startup and shutdown and I've found a circuit on this site that will generate a trapezoidal profile using a 555 timer. (https://m.eet.com/media/1144287/203799f1.pdf)
It seems to me that I would need to use such a circuit to ramp up the motor, then switch over to my encoder signal to drive it, then switch back to the 555 circuit when I want to ramp down. This seems a very cumbersome arrangement.
My question is, how can I ramp up my stepper motor, given that I have a continuous input pulse stream of approximately constant frequency?