Which of the following functions is needed to control the speed of a motor using PWM?analogWrite()digitalWrite()else

The function needed to control the speed of a motor using PWM (Pulse Width Modulation) is analogWrite().

Here's why:

1. PWM is a technique used to generate analog signals with digital means. It can be used to control the speed of a motor by varying the width of the pulses in a pulse train, which effectively changes the average voltage of the signal.

2. The analogWrite() function in Arduino is used to write a PWM signal to a pin. You can specify the pin and the duty cycle (a value between 0 and 255, with 0 meaning 0% duty cycle or always off, and 255 meaning 100% duty cycle or always on).

3. digitalWrite() function, on the other hand, can only turn a digital pin on or off, but it cannot control the speed of a motor because it cannot generate a PWM signal.

4. "else" is not a function, it's a control statement used in programming to specify a block of code to be executed if an if statement is false.

So, to control the speed of a motor using PWM, you would need the analogWrite() function.