Arduino motor control using digital pins I am new to these Arduino things, and I am currently using an Uno board for my projects.

I don't know how to control the DC motor with the help of digital pins via L293D. But I cannot use the PWM pins of Arduino, since I have already used them for controlling servos and other things, which need higher accuracy.

I tried using the SoftPWM library to control motor, but it is conflicting with other things like ultrasonic sensor. I don't know what the problem is.

Could someone suggest me a solution?
You can implement PWM using digital pins by turning the pin on and off with respect to your duty cycle, because PWM (Pulse Width Modulation) depends upon the duty cycle the % amount during which the pin is HIGH or LOW

Let say pin 13 of arduino is connected to your l293D enable pin

Sample Code:

void setup()
{
  pinMode(13, OUTPUT);
}

void loop()
{
  digitalWrite(13, HIGH);
  delayMicroseconds(100); // Approximately 10% duty cycle @ 1KHz
  digitalWrite(13, LOW);
  delayMicroseconds(1000 - 100);
}

Details are also on Arduino Help

https://www.arduino.cc/en/Tutorial/SecretsOfArduinoPWM