Is the ADC problem fixed?

A PIC cannot directly drive a motor, you will need a motor driver, to recommend one, we need information about the motor and load the motor will be moving.

code and schematic will help a lot for things overlooked and potential other issues.

yes adc is fine now the readings on the LCD are correct
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there is H-Bridge connected between the pic and the motor
but the problem is that the output from the pic is very small

 

What did you change to get the ADC working? That may prove to be helpful for others that ran into the same issue.

What H-Bridge are you using?

Are the motors basic fwd/rev, or PWM/Speed control forward/reverse?

When the H-Bridge is out of circuit, what is the voltage on the I/O Pin?

 

What did you change to get the ADC working? That may prove to be helpful for others that ran into the same issue.
What H-Bridge are you using?
Are the motors basic fwd/rev, or PWM/Speed control forward/reverse?
When the H-Bridge is out of circuit, what is the voltage on the I/O Pin?

What did you change to get the ADC working? That may prove to be helpful for others that ran into the same issue.
I fixed the frequency
What H-Bridge are you using?
L293D
Are the motors basic fwd/rev, or PWM/Speed control forward/reverse?
fwd/rev
When the H-Bridge is out of circuit, what is the voltage on the I/O Pin?
5volts at the I\O pins

 

When the H-Bridge is out of circuit, what is the voltage on the I/O Pin?
5volts at the I\O pins

Double check your wiring or check the H-Bridge in a known good circuit. Will the H-Bridge drive motors if the same input lines ae driven high by a 1k resistor to +5V?

What is the secondary power to the H-Bridge (Motor power)? Are logic and power reversed?