Using Arduino's Internal Timers for Timing Functions

Internal Timers of Arduino

The Arduino is programmed using the Arduino Language and the Arduino Integrated Development Environment (IDE). The Arduino IDE is an open source program used to write and upload code to the Arduino board. One of the many features of the Arduino is its internal clock, or timer.

The internal clock is a hardware feature of the Arduino that allows it to track time without requiring an external clock. The internal clock can be set to any frequency, and this clock is used by all functions which require timing, such as delays and serial communication.

The Arduino uses two different types of internal timers: the Timer/Counter0 (TC0) and the Timer/Counter1 (TC1). TC0 is used for basic timing, such as with the delay() function. TC1 is used for advanced timing, such as with interrupts. Both of these timers have 16-bit registers in which time is stored.

In addition to setting the frequency of the clock, the user can also control how the timer is counted. There are four different modes in which the timer can be operated: Normal Mode, CTC Mode, Fast PWM Mode, and Phase Correct PWM Mode.

The Normal Mode is the simplest mode and is generally used for delay() functions. The CTC Mode is used for comparing two values, and is often used for interrupts. The Fast PWM and Phase Correct PWM Modes are used for generating Pulse Width Modulation signals, which are commonly used to control servo motors and other devices.

The internal timers of the Arduino are incredibly useful for keeping track of time and for controlling output devices. To learn more about the internals timers of Arduino, check out the Arduino Reference Manual.

The internal timers of an Arduino can be accessed using the Timer library. Here is an example code that demonstrates how to use Timer1 to generate a PWM signal:

#include <TimerOne.h>

const int ledPin = 9;

void setup() {
  pinMode(ledPin, OUTPUT);
  Timer1.initialize(1000); // set timer period to 1 ms
  Timer1.pwm(ledPin, 512); // set initial duty cycle to 50%
}

void loop() {
  // do other things here
}

In this example, the TimerOne.h library is used to access Timer1. The ledPin is defined as the output pin connected to an LED.

In the setup() function, the ledPin is set as an output pin, and the Timer1.initialize(1000) function is called to set the timer period to 1 millisecond.

The Timer1.pwm(ledPin, 512) function is used to set the initial duty cycle of the PWM signal to 50%. The duty cycle can be changed by calling this function with a different value between 0 and 1023.

In the loop() function, other tasks can be performed while the timer is generating the PWM signal.

Note that the Timer library can be used to access other timers of the Arduino, such as Timer0 and Timer2. The syntax for using these timers is similar to the example shown for Timer1