DTMF Controlled Robot without Microcontroller

Project Title

DTMF Controlled Robot without Microcontroller

Project Area of Specialization RoboticsProject Summary

In this project, I will show you how to design a simple Robotic vehicle that can be controlled using a phone. The project is called DTMF Controlled Robot without Microcontroller.

DTMF is an acronym for Dual Tone Modulation Frequency. Robotic vehicle based on DTMF technology. DTMF is a circuit that operates the robot without using a microcontroller. This circuit consists of simple DTMF Tone decoder IC and a motor driver IC.

Project Objectives

Following are the objectives of the project

identify the devices

purchase of the devices

assembly and connection

coding and communication

testing of the system.

Project Implementation Method

When a key is pressed from our mobile, it generates a tone, which is a combination of two frequencies. Of the two frequencies, one is high frequency and another one is low frequency. This frequency can be decoded by the decoder IC into binary sequence. Using this binary sequence, the robot is controlled.

Benefits of the Project

• DTMF robot with slight modifications can be used in industrial applications.
• DTMF robot with human detector sensor can be used at the time of disasters like earth quake to detect the human under buildings.
• DTMF robot with camera can be used in surveillance systems.

Technical Details of Final Deliverable

DTMF based robotic vehicle circuit consists of DTMF Decoder IC, Motor Driver IC (L293D or L298N), motors and a simple robot chassis to hold all these components.

DTMF decoder IC used is HT9170B (actually a variant called CM8870 is used but the functionality is the same). It has 18 pins. Tone from DTMF encoder is given to the DTMF decoder IC. The decoder IC internally, consists of operational amplifier, whose output is given to pre filters to separate low and high frequencies. 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 ‘8’, it gives a decoded output of ‘1000’ (in the order of Q1, Q2, Q3 and Q4). Thus motor connected to the first two pins (OUT1 and OUT2) will rotate and the second motor stays off. So, the 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 above table gives the low frequency, high frequency and binary output value of each button pressed in the keypad.

Final Deliverable of the Project HW/SW integrated systemCore Industry ITOther Industries Transportation , Others Core Technology RoboticsOther Technologies OthersSustainable Development Goals Industry, Innovation and InfrastructureRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	72810
Android mobile for access of hardware	Equipment	1	35000	35000
publication and Thesis fee	Miscellaneous	2	5000	10000
DTMF Decoder IC (HT9170B or CM8870)	Equipment	4	700	2800
Motor Driver IC (L293D or L298N)	Equipment	4	600	2400
Resistors – 100K? x 2, 330K?	Equipment	200	8	1600
Capacitors – 100nF x 2, 22pF x 2	Equipment	100	4	400
1pcs 4Pin 3.3v-5v Active SMD Crystal	Equipment	2	790	1580
Robot Chassis	Equipment	2	915	1830
Batteries	Equipment	10	20	200
HP 24mh FHD Monitor - Computer Monitor for tracking the roads	Equipment	1	17000	17000