User manual

Basys MX3™ Board Reference Manual
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Page 33 of 56
Figure 14.1. Motor driver schematic diagram.
The MODE signal selects one of the two operating modes: logic low selects IN/IN mode, while logic high selects
PH/EN mode.
When using IN/IN mode, the logical values of AIN1, AIN2, BIN1, BIN2 control the 4 command signals of a stepper
motor: A1, A2, B1, B2.
When using PH/EN mode:
 AIN1, AIN2 signals (through their APHASE, AENABLE functions) control the Phase (direction) and Enable of
the H Bridge - the DC motor A (outputs A1, A2) driver
 BIN1, BIN2 signals (through their BPHASE, BENABLE function) control the Phase (direction) and Enable of
the H Bridge - the DC motor B (outputs B1, B2) driver.
The voltage on the output pins A1, A2, B1, B2 is dependent of the motor supply power applied to the motor
controller. It is possible to use the VBAR power pin (5V - the power from the external barrel), or an external power
supplied by the user using the VEXT / GND pins of the MOTOR OUT connector block (0V to 11V). These two options
are selectable using the MOTOR PWR jumper block (situated just above the MOTOR OUT connector).
Using the motors with the jumper on the VBAR position requires external power source connected to the barrel
power connector.
The Table 14.1 details the usage of the MOTOR PWR jumper block:
Jumper position
Description
VBAR
The power provided from the external power supply (using the barrel
connector) is used for motors.
VEXT
The power VEXT provided from an external supply (using the VEXT pin
of the MOTOR OUT connector block) is used for motors.
Table 14.1. Motor power selection.
Please read the Texas Instruments DRV8835 datasheet for more details about the motor controller.
14.1 Connectivity
Table 14.2 shows the signals connecting the Motor Driver to the PIC32.