I have made project " DTMF Based Land Rover ". The whole circuit is working in usual manner. The voltage at arduino output pins is 3.46 volts. And pin no 16 and 8 are Vcc of L293d respectively So they are connected to 6V. When arduino output is driven into motor drive ic L293d, motors connected at output of ic is not rotating. So can anyone tell me why the motor is not rotating. ( According to me it can be because of low voltage at input pins of L293d. So can anyone suggest how can i increase the voltage at input pins ) If this is due to some different reason, kindly please help me with solution.
Make sure that you set the enable pins (pins 1 and 9 on the IC) to the correct logic levels to enable the PWM output for the direction you want to turn in.
The datasheet has a lot of information on how to properly use this IC (http://www.ti.com/lit/ds/symlink/l293.pdf)
It sounds like you might be working on a project as a beginner, so here's an instructable that I found online that you can use for reference: https://www.instructables.com/id/L293D-Motor-Driver/