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![]() ![]() Outside of the already given Arduino functions (delay(), millis(), servo, tone, etc. They allow you to sample, control hardware or measure signals at very precise intervals. Timers are extremely powerful and useful microcontroller functions. Create your ISR to toggle the LED and reset the timer. ![]() Don't forget to set the output compare A interrupt enable bit in TIMSK1 and enable global interrupts! Now, whenever Timer1 reaches 31,250, a TIMER1_COMPA interrupt will occur. We set the prescaler to 256 and load 31,250 into the OCR1A register. ![]() You can see how Timer1 increments on every rising edge of the system clock. For example, here is Timer1 counting up to 15 with no prescaler. A prescaler, in effect, divides the system clock to make something operate more slowly. To help make timing longer events easier (especially when some of the timers can only count up to 255), a prescaler can be used. This type of interrupt is good for measuring the time between pulses. Input Capture - When a specific pin changes value (e.g., ICP1), the current timer value is stored in another register (ICR1) that can be retrieved later to see the exact time that event occurred.Overflow interrupts are also used for PWM signals and running pieces of code at precise intervals. Overflow - When the timer rolls over from its max value (e.g., 65,535) to 0, an interrupt is generated.This can be useful for creating pulse width modulation (PWM) signals on pins or sampling a sensor at specific intervals. Using the same Arduino board to provide an input to the External Interrupt block may result in a racing condition between the input signal and the ISR. Compare Match - When the timer value reaches a specific value (stored in the corresponding output compare register), an interrupt will be generated.Each of these timers can be configured for one or more interrupts: ![]()
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