What is the difference between indexer control, and Serial control?

Thread Starter

FlightSim12

Joined Jun 21, 2016
2
I am trying to choose a stepper motor controller for a 2 phase unipolar stepper, and I don't want PWM because I have limited PWM outputs on the microcontroller I am using. So I looked around and found stepper motor drivers that are controlled by an indexer and Serial(such as SPI). But I cannot find a satisfactory explanation of indexer control, so I would like to know whether or not the indexer step/dir control pins just work off of plain binary, like a 0 for clockwise and a 1 for counter clockwise, and a 0 for no movement and a 1 for "move one step"? I would also like to know the pros and cons of each control type.
 

Sensacell

Joined Jun 19, 2012
3,131
Note that an "indexer" and "driver" are two different beasts entirely.

A stepper "driver" accepts step and direction inputs- this makes you in charge of handling the (non-trivial) pulse counting and timing tasks required.

An "indexer" is a device that creates the step and direction signals itself from macro 'move' commands you send it, handling all the messy stuff internally. An indexer typically needs a driver, although some combine both.
 

MaxHeadRoom

Joined Jul 18, 2013
26,625
A simple indexer uses a pulse chain the rate of which controls the rpm, a separate 1 - or 0 input decides the direction.
Most drives use this method, the PWM is used for the actual coil switching, the old series resistor method can also be used for non-switched outputs.
Max.
 

Thread Starter

FlightSim12

Joined Jun 21, 2016
2
A simple indexer uses a pulse chain the rate of which controls the rpm, a separate 1 - or 0 input decides the direction.
Most drives use this method, the PWM is used for the actual coil switching, the old series resistor method can also be used for non-switched outputs.
Max.
So that would be the easiest method for controlling multiple steppers with a microcontroller connected to a Stepper motor driver IC that uses the indexer like this chip from TI? http://www.ti.com/product/DRV8805/datasheet
 
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