Question

How can we implement PWM with another processor such as the Intel i7.

what are some methods to achieve PWM with the Arduino?

Answer 1

How can we implement PWM with another processor such as the Intel i7. what are some methods to achieve PWM with the Arduino?
Implementation of PWM in processor
The full form of PWM is Pulse-Width-Modulation. In this modulation approach, voltages are generated using digital pulse. In any analog circuitry, different voltages range can be possible to achieve, whereas in digital voltages are in the range either 1 or 0. ‘1’ means any analog voltage range such as 5v, 3.3v etc.
Now, if you continuously on and off a particular switch, you will be able to generate two static voltage either 5V or 0V (i.e. digital 1 and 0) for the duration of the switch on and off duration. If you need to ON a switch for a certain deration and OFF for a certain duration, manually it is not possible, hence we need to code for that particular switch. This operation is mainly known as PWM operation of any microcontroller.
PWM has many requirements and specifications which are very important to assure that the generated PWM signal will be received by the other device. Hence, the receiver device needs to be activated for certain duration in order to activate. The period of PWM creates a frequency. During this period, the digital pulse is producing ON and OFF consecutive bits. The frequency can be calculated as the number of such period in 1 sec. Assuming the length of period is 1ms. Then the frequency of operation of that particular PWM channel is 1/1ms = 1kHz.
There are two types of PWM generation principles: PWM can be generated at the middle or it can be generated at the end of the period. Based on that information, the duty cycle of the specific pulse has been achieved. The duty cycle can be defined as the percentage of time duration of the period in which the pulse is in ON state. Therefore, 10% duty cycle means 10% time of the period of the pulse is ON and rest of the time that means 90% amount of time it is in the OFF state.
In any kind of processor such as intel i7, such PWM signal are mainly generated by the clock source and the build-in timer mechanism. One can control the internal timer to count up and then set back to 0 after a specific count, so that the timer will count up and again back to 0 over and over again which creates the period. While you are controlling the pulse, we can turn on the switch for a specific count and again off it for a specific count thus creating the PWM signal. In all of present scenarios, PWM signal inside the processor is generated using the above principle.
Methods to achieve PWM in Arduino
In Arduino, the ATmega 168 microcontroller chip has been employed. There are several ways by which the PWM in Arduino can be generated.
1.   Simple PWM generation using analogWrite function
In this mode, the user only needs to call the analogWrite function. The pin no and duty cycle information’s are required to be passed. Where, the pin no is basicaaly 3.5.9.10 or 11 and the duty cycle defined the % of period of the ON time of the pulse.
2.   Bit-banging PWM
In this mode, PWM can be generated manually by turning the pin on and off for the desired amount of time. Here, the Arduino digital pins can be utilized however the main drawback is that any interrupts can affect the timing.
3.   PWM generation by ATmega registers
The ATmega168 chip has 3 PWM timer pin which can control 6 PWM outputs. While manipulating the chip timer value, the PWM signal can be directly generated.
4.   Fast PWM mode
In this mode, the timer counts 0 to 255. Output is turned on when the counter counts 0. With increasing count the timer will on/off the pulse based on the requirement. This mode is called as fast PWM mode.