Block diagram of the DTMF control robot

The block diagram of the DTMF control robot is divided into following section

  1. Mobile phone
  2. DTMF decoder
  3. Microcontroller
  4. Motor Driver
  5. Motor

Mobile phone

The mobile phone is used for the generation of the DTMF signal. The mobile keypad is used for the controlling robot action (activity). The output of the DTMF tone is taken from the speaker and feed to the DTMF decoder block.

DTMF decoder


The DTMF decoder is decodes the DTMF signals and convert them into the binary coded decimal number. Now these BCD number is used for the other digital processing data. The output of the DTMF decoder is applied to the microcontroller.

Microcontroller

The microcontroller is take the digital input from the DTMF decoder and take the decision to control the robot movement in a desirable path. The output of the microcontroller is feed to the motor driver IC.

Motor Driver

The motor driver IC is drives the motors which provide the rotation of the robot wheel. Motor Driver IC takes the digital logic input and amplifies it as the desirable level and drive the motor.

Motor

A DC geared motor is used to provide the mechanical movement of the robot.

Circuit Diagram of the DTMF control robot

The circuit diagram of the DTMF control robot is divided into the following section

  1. Mobile phone
  2. DTMF decoder (8870)
  3. Microcontroller (AT89S51)
  4. Motor Driver (L293D)
  5. Motors

Mobile Phone

All the mobile phones are generate the DTMF signal when their keys are pressed and these signals are used for the controlling the hardware like motors. The output is taken from speaker and provides the DTMF decoder IC to decode these signals.

DTMF decoder (8870)

The DTMF decoder IC (8870) is used to decode the DTMF tone and convert it into the BCD number that is digital logic. These digital logic signals can be used for the microcontroller input for the further processing.

Microcontroller (AT89S51)

The microcontroller AT89S51 is used to take the decision according to the digital input. Microcontroller sense the input and according to the number it control the wheel rotation the motor for example 1 is used for the forward direction,8 is used for the backward direction, 4 is used for the left direction and 6 is used for the right direction. According to these keys a program is feed into the microcontroller to take such types of decision. Now the output of the microcontroller is feed to the motor driver IC.

Motor Driver (L293D)

The motor driver IC L293D is used to drive the gear motor. The L293D IC consist 2 H-Bridge that can drive two motors at a time. The motor driver L293D increase the voltage and current level up to desirable level so two DC geared motor drive at a time which have 500 mA current rating.

Motors

The DC geared motor is used to provide the mechanical movement of the robot. According to the speed 5 to 1000 RPM motor can be used for it. A high RPM motor provides less torque. For robotic movement used two motor diagonally to provide rotation and two dummy motors is used for the support of the robot.