MD-4 8031 Microcontroller Stepper motor driver kit
information and resources on stepper motor drivers see the
Click image to enlarge
The MD4 is a
stepper motor driver design utilizing the 80C31 microcontroller. The design is very similar to the
MD-2 stepper motor driver board except that this board has an on-board +5V regulator so it does
not require a dual voltage power supply to run. It uses two Allegro
UDN2540B ICs to driver the stepper motors. The U1 is 8031AH microcontroller which can be
replaced with any 80C32,87C51,87C52 or flash base microcontroller
The port P1.0~P1.7
generate the step sequences to drive the stepper motors with U2 and U3
(UDN2540B). The port P3.4 and P3.5 enable/disable the power supply to the
motors. You may wonder why does the design use Q2 & Q3 to turn on/off the
power to the J2 motor instead of the using the enable pin on U2? Well, in
some applications which require the motor to lift a heavy load, if the
simple belts drive or gears drive system is used, then when the motor is
stopped, The holding torque of the motor alone may not able to hold the load
in place. Of course using the worm gear or lead screw can easy solve the
problem but they are not cost effective. If we apply some low voltage to the
motor after it stop, that enough to lock the motor in place without overheat
the motor, this way will increases the holding torque and serves the same
purpose without adding cost to the whole system.
When Q2 is cut off, there's still some
voltages apply to the motor winding thru R9. You may need to change the R9
value depending on the motor winding resistance. The R9 is omitted if there
is no need to increase the motor holding torque.
In our EPROM sample code, we configured the J4 as input ports for
controlling the two motors. Their functions are as follows:
J4-Pin1-------- Motor0 enable
J4-Pin4-------- Motor0 direction
J4-Pin6-------- Motor1 enable
J4-Pin8-------- Motor1 direction
Shorting the pin1 to ground (pin2) will turn on the Motor0 in one
direction, with the Pin4 shorts to ground first then Pin1, the Motor0 will
rotate in opposite direction. Same functions are on Pin6 and Pin8 for
Motor1. Jumper J6 and J7 are not used in our sample code, but you may change
the program so that with the different jumper setting on J6 & J7, the motor
will run at different speed.
You can download the Intel
hex code and the
source file here.
We offer the MD4 as a kit so you can build it yourself and customize it as
Assembling the board
should be very simple and straightforward. Make sure you use the IC sockets
for U1 and U5. We hope that we don't need to show you how to identify the
resistor or capacitor value, IC and diode orientation etc. but if you are
beginner in electronics and
need our help then just let us know.
A heatsink for the Q1 (7805) is required, Q2
needed. The ZD1 & ZD2 are options, you may just use the jumper wire or 0
Ohm resistor instead.
The locking tab of the 6pin and 9pin headers for J2,J3 and J4 are
facing the outside edge of the board. If you look at the solder side of the
PC board, the square pad is pin1. Make sure you put the shunt on J5. The
finishing board should look similar to this picture.
are connected to J2 and J3. Incorrect motor winding connections may damage
the driver chip, see the picture below for proper motor connections.
Figure 2 Stepper Motor connections
For your convenient you may download this
page in MS word format.
The KIT which includes all the components and
PCB for just $20.00 plus shipping/handling.
Back to Projects Page
View other projects:
Motor Driver Boards
Passive components |
| CCD Camera / Module
@1990 8031 stepper motor controllers