You may have come across many schematics and projects about a cell phone controlled land rover in many websites. But this is not the same. This article will show you how to make a cell phone controlled land rover without using a microcontroller. You read it right we are not going to use any kind of costly microcontroller for making the rover.
Description
Description
We’ll just need a DTMF decoder MT8870 and a motor driver L293d for making it. So no circuit complexity, no costly ICs and no programming required.
A DTMF decoder is a device which takes a signal from the headset line of a cell phone and gives a 4 bit output corresponding key pressed in the cell phone. Whenever a key is pressed in the mobile, a sum of two fixed frequency is sent as input to the decoder IC. This IC converts the number into its corresponding binary value for example if 3 is pressed its binary value 0011 is produced at the output.
The motor driver L293d can control 2 motors bi-directionally and has 4 inputs. The 4 outputs from the decoder IC is fed into the 4 inputs of the motor driver directly without using complicated circuits.
The Table below shows you how the Robo works :-
|
Number Pressed
|
Output of DTMF decoder
|
Input to the Motor driver
|
Right Motor
Action
|
Left Motor
Action
|
Robot’s Net Movement
|
|
6
|
0 1 1 0
|
0 1 1 0
|
Forward
|
Forward
|
Forward
|
|
9
|
1 0 0 1
|
1 0 0 1
|
Reverse
|
Reverse
|
Reverse
|
|
4
|
0 1 0 0
|
0 1 0 0
|
Forward
|
Stop
|
Left
|
|
2
|
0 0 1 0
|
0 0 1 0
|
Stop
|
Forward
|
Right
|
|
0
|
0 0 0 0
|
0 0 0 0
|
Stop
|
Stop
|
Stop
|
|
Components
|
Quantity
|
|
Resistors
100k
330k
|
2
1
|
|
Capacitors
22pF
0.1uF
0.47uF
|
2
1
1
|
|
Crystal
3.57Mhz
|
1
|
|
ICs
Motor Driver L293D
DTMF decoder MT8870
|
1
1
|
|
DC Geared Motors 6V
|
2
|
|
SLA Battery 6V,4.5Ah
|
1
|
Advantages:-
Well you must have already come across the usual advantages of cell phone controlled Robot like, interference free communication, long range, etc. Lets see what’s more beneficial in this robot.
1. Reduces circuit complexity.
2. No need of any Programming.
3. Cost is highly reduced. Not everyone can afford a microcontroller along with its programmer and debugger boards.
Video
Circuit Diagrams
Filed Under: Electronic Projects