The BiStep includes the capability of driving one or two stepper motors, each of which being either unipolar (4-pole) or bipolar (2 pole). This unit is a good choice for those designing products using linear actuators, especially since the microstepping features will reduce noise levels and can increase positional accuracy by a significant amount.

Motor Mind B

BiStep(#30004)



The BiStep includes the capability of driving one or two stepper motors each of which being either unipolar (4-pole) or bipolar (2-pole). This unit is a good choice for those designing products using linear actuators, especially since the microstepping features will reduce noise levells and can increase positional accuracy by a significant amount.

The board is specified as allowing up to 1.0 amps per motor winding, with 7.5 to 15 volt motors supported when in single power supply mode. It also supports a dual power supply feature, wherein the motors use a separate supply from the logic circuits; in this mode, up to a 35 volt power supply may be used for the motors.

The BiStep may be optionally configured to act as a serial router for our product line, through usee of the SerRoute firmware option. This option replaces the stepper motor control with serial routing of up to 5 boards, 8 relay, and up to 4 TTL input operations.


Downloads:
BiStep Motor Controller (.pdf)

The BiStep version A05 has the following capabilities:

  • Up to two stepper motors may be independently controlled at one time.
  • Each motor may be either 4-pole Unipolar or 2-pole Bipolar.
  • Each motor may draw up to 1 amp per winding. Note if more than 0.5 amp motors are used, then the board requires external fan-based cooling; otherwise the board can overheat and fail if the motors are left enabled for long periods of time.
  • The connectors to the motors are explicitly designed to be reversible; this means that to reverse the default direction of an attached motor, merely remove the connector and turn it around.
  • Limit switches may be used to automatically request motion stop of either motor in either direction.
  • Rates of 1 to 62,500 microsteps per second are supported.
  • Step rates are changed by linearly ramping the rates; the rate of change is independently programmed for each motor, and can be from 1 to 62,500 microsteps per second per second.
  • All motor coordinates and rates are expressed in programmable microstep units of 1/2 to 1/64 of a full step. Once the base step size is selected, changing stepping modes between half, full and micro does not change any other value other than which winding pairs may be driven at the same time.
  • Motor coordinates are maintained as 32 bit signed values, and thus have a range of -2,147,483,647 through +2,147,483,647.
  • Both GoTo and Slew actions are fully supported.
  • Four modes of stepping the motor are supported:
  • Half steps (alternates 1 winding and two windings enabled at a time),
  • Full power full steps (2 windings enabled at a time)
  • Half power full steps (1 winding enabled at a time)
  • Near-constant-current microsteps (each from 1/64 to 1/2 of a full step)
  • A TTL "busy" signal is available, which can be used to see if the motors are still moving.
  • Note that this information is also available from the serial communications subsystem.
  • Simple control of the motors may be done by switch closure: i.e., each motor can be told to slew left or right, or to stop by simply grounding some input lines. Similarly, the rate of motion can be controlled via stepping through a standard set of rates via grounding another input.
  • Complete control of the motors, including total monitoring of current conditions, is available through the 2400 or 9600 baud serial connection.
  • An additional mode is available which allows an external computer to directly generate step sequences on the motor control lines. Up to 62,500 microsteps per second may be requested.
  • The system can be configured to operate in 1/2 power mode, wherein it reduces the power to all windings by 1/2 for all actions. This can be used to "overvoltage" a motor, in order to generate more torque.
  • Runs off of a single user-provided 7.5 to 15 volt DC power supply. May also be configured using a split supply, wherein the motor runs off of a 7 to 35 volt DC power supply, while the logic circuit runs off of a 7.5 to 15 volt supply.
  • Theoretically, an unlimited number of boards can be controlled via one serial line, if the SerRoute product is used.