Posted by Circuits Arena on Monday, 5 September 2016
DTMF Controlled Robot without using Microcontroller is the artlcle explaining DTMF Controlled Robot without using Microcontroller DTMF based robotic vehicle circuit consists of DTMF decoder IC, driver IC l293D IC ...
DTMF Controlled Robot without using Microcontroller
DTMF based robotic vehicle circuit consists of DTMF decoder IC, driver IC l293D IC and motors.
1.DTMF decoder IC used is HT9107B. It has 18 pins. Tone from DTMF encoder is given to the DTMF decoder IC.
2.The decoder IC internally, consists of operational amplifier whose output is given to pre filters to separate low and high frequencies.
3.Then it is passed to code detector circuit and it decodes the incoming tone into 4bits of binary data. This data at the output is directly given to the driver IC to drive the two motors. These motors rotate according to the decoded output.
If the
button pressed from mobile is ‘1’, it gives a decoded output of ‘0001’.
Thus motor connected to the first two pins will get 0 volts and second
motor will have 5 volts to one pin and 0 volts to the another pin. Thus
second motor starts rotating and first motor is off. So, robot moves in
one direction either to left or right. If the robot is to rotate
forward or backward then the binary value should be either ‘0101’ or
‘1010’.These values indicate that two motors rotates in the same
direction i.e. either forward or backward. The following table gives the
low frequency, high frequency and binary output value of each button
pressed in the keypad.
DTMF Decoded Frequency Output Table
Circuit Diagram of DTMF Controlled Robotic Vehicle without using Microcontroller:
DTMF based Mobile Controlled Robot Circuit Diagram
Circuit Components:
- DTMF Decoder IC (HT9107B)
- Motor Driver IC
- Motors
- Resistors – R1, R2 & R3
- Capacitors – C1 to C4
- Crystal
DTMF Controlled Robot Circuit Design:
The main
components of the circuit are DTMF decoder IC, motor driver IC and
motors. The decoder IC used here is HT9107B IC. The second pin of
decoder IC is an inverting pin of the operational amplifier.
Tone is
applied to the IC through a series of capacitor and resistor. The output
of the Op Amp is feed back through GS pin of the IC. An external
crystal is connected to the 7th and 8th pins of the IC.
Motor
driver IC used is L293D. It has 16 pins. 2, 7, 10, 15 pins are the
inputs of motor driver IC connected from output pins of the decoder IC.
The output pins are 3, 6, 11, 14. These pins are connected to the two
motors of robotic vehicle. 8th pin is connected to the 5v.
Vss is the input voltage with which the motors runs. Motors cannot be
driven with 5Vof microcontroller. So, a driver IC is used to amplify
this voltage. VSS pin provides this voltage.
