|Demand Peripherals Robotics and Automation Made Easy|
STEPU: Unipolar Stepper Motor Controller
The STEPU peripheral controls the step rate, direction, and target step count of a unipolar stepper motor. You can incrementally add counts to the target step count.
The unipolar stepper motor controller controls the on/off state and direction of four open-drain drivers connected to the coils of a unipolar stepper motor. The STEPU peripheral is most often paired with DRV4, the quad open-drain driver card. More information about the DRV4 card can be found here: cards/drv4.html.
Resources for the unipolar stepper motor controller let you control direction, step rate, and select either full or half steps.
config : controller configuration.
[mode],[direction],[rate],[hold current %]\\nThree modes of operation are available: off, full-step, and half-step. The mode is specified as one of the words 'off', 'full', or 'half'. The first letter of each word can also be used. The off mode removes all power to the drivers. The power on default mode is off.
The direction is given as 'forward' for a step sequence of ABCD and 'reverse' for a sequence of DCBA. The single letters 'f' and 'r' can also be used. The default is forward.
The motor step rate is given in Hertz. The driver tries to use a step-rate as close as possible to the one specified. For example, a requested step-rate of 511 Hertz might result in an actual step rate of 500 Hertz. The step rate has 8 bits of accuracy, and a range from 4 Hertz to 1 MHz.
The holding current is given as a percentage of full current and is in the range 0 to 99 percent.
Sample configuration lines include the following:
off forward 400 10 half reverse 125 25 f f 200 99
count : target step count.
addcount : synchronously add counts to target.
Step in the forward direction for 200 full steps at a step rate of 40 steps per second and use a holding current of 10 percent of full power.
dpset stepu config full forward 50 10 dpset stepu count 200