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1. REMOTE CONTROLLING OF
STEPPER MOTOR DIRECTION
AND SPEED USING MOBILE.
By:
E. Arun Kumar
N. Archana
V. Swetha

2. Stepper Motor finds it applications in various areas.
• COMPUTER APPLICATIONS
• INDUSTRIAL APPLICATIONS
• WIND TURBINES

3. Block Diagram :
Power
Supply
L.C.D
D.T.M.F
Decoder
Stepper
Micro Motor 1
Controller
(AT89C52)
Motor
Driver
Mobile
Phone
Stepper
Motor 2

4. Components :
 HARDWARE
 IC 7805
 AT89C52 (UC)
 HT9170b (DTMF DECODER)
 ULN2803a (MOTOR DRIVER)
 Stepper Motor
 L.C.D ( HT44870)
 SOFTWARE Keil

5. Micro Controller :
 8K Bytes of In-System Reprogrammable
Flash Memory
 Endurance: 1,000 Write/Erase Cycles
 Fully Static Operation: 0 Hz to 24 MHz
 Three-level Program Memory Lock
 256 x 8-bit Internal RAM
 32 Programmable I/O Lines
 Three 16-bit Timer/Counters
 Eight Interrupt Sources
 Programmable Serial Channel
 Low-power Idle and Power-down Modes

6. Stepper Motor Types :
• Unipolar Stepper Motor: Unipolar stepper motors are
characterised by their center-tapped windings.

7.  Bipolar Stepper Motor: Bipolar stepper motors are
designed with separate coils.

8. • Hybrid Stepper Motor : Variable reluctance stepper motor (also
called hybrid motors) are characterised by one common lead.

9. Motor Driver :
• Output current up to
500mA
• Output voltage up to 50V
• Internal suppression
diodes
• Eight Darlington with
eight emitters
• Outputs can be
parallelized

10. DTMF:
 Dual-tone multi-frequency signaling (DTMF)
is used for telecommunication signallingover
analog telephone lines in the voice-frequency
band between telephone handsets and other
communications devices and the switching
center.
 A DTMF signal is the algebraic sum of two
different audio frequencies, and can be expressed
as follows:
f(t) = A0sin(2*П*fa*t) + B0sin(2*П*fb*t) +
………..

11. • The frequencies associated with various keys on the
keypad are shown in figure (A).

12. HT9170b :
•Operating voltage:
2.5V~5.5V
•Minimal external
components
•No external filter is required
•Low standby current (on
power down mode)
•Excellent performance

13. L.C.D :
 Alpha Numeric L.C.D with
16 pins.
 7-14 pins are data pins.
 L .C.D used is 2x16.

14. Flow Chart :
start
Display Characters on
L.C.D
If key
pressed
Display Corresponding Key on
L.C.D rotate motor
depending on key pressed
Stop

15. Conclusion :
 It finds its application in X-Y Plotter used in industrial
applications.