  In the recent past, wireless controlled vehicles had been extensively used in
a lot of areas like unmanned rescue missions, military usage for unmanned
combat and many others. But the major disadvantage of these wireless unmanned
robots is that they typically make use of RF circuits for maneuver and control.
Essentially RF circuits suffer from a lot of drawbacks such as limited
frequency range i.e. working range, and limited control. To overcome such
problems associated with RF control, few papers have been written, describing
methods which make use of the GSM network and the DTMF function of a cell phone
to control the robotic vehicle. This paper although uses the same principle
technology of the GSM network and the DTMF based mobile phone but it
essentially shows the construction of a circuit using only 4 bits of wireless
data communication to control the motion of the vehicle without the use of any
microcontroller. This improvement results in considerable reduction of circuit
complexity and of manpower for software development as the circuit built using
this system does not require any form of programming. Moreover, practical
results obtained showed an appreciable degree of accuracy of the system and
friendliness without the use of any microcontroller.
