Instructions, it can be read incorrectly. Volatile, if the interrupt changes a multi-byte variable between a sequence of When accessing shared variables, usually interrupts must be disabled. Because yourįunction may change variables while your program is using them, the compiler needs Volatile tells the compiler toĪvoid optimizations that assume variable can not spontaneously change. Variables usually need to be "volatile" types. Special design is necessary to share data between interrupt code and the To minimize the time // with interrupts off, just quickly make a copy, and then // use the copy while allowing the interrupt to keep working. Unsigned long blinkCopy // holds a copy of the blinkCount // to read a variable which the interrupt code writes, we // must temporarily disable interrupts, to be sure it will // not change while we are reading. The main program will print the blink count // to the Arduino Serial Monitor void loop( void) Volatile unsigned long blinkCount = 0 // use volatile for shared variables void blinkLED( void)īlinkCount = blinkCount + 1 // increase when LED turns on The interrupt will blink the LED, and keep // track of how many times it has blinked. attachInterrupt(blinkLED) // blinkLED to run every 0.15 seconds Serial. const int led = LED_BUILTIN // the pin with a LED void setup( void) This example uses the timer interrupt to blink an LED // and also demonstrates how to share a variable between // the interrupt and the main program. Interrupt, so special care is needed to share any variables beteen the interruptĭisable the interrupt, so the function no longer runs. Run a function each time the timer period finishes. The pin reverts to being controlled by digitalWrite(). Must be used at least once to configure the pin. This is slightly faster than pwm(), but pwm() Set a new PWM, without reconfiguring the pin. Pin always LOW and 1023 makes the pin always HIGH. "duty" is from 0 to 1023, where 0 makes the pwm(pin, duty) Ĭonfigure one of the timer's PWM pins. Restart the timer, from the beginning of a new period. Set a new period after the library is already initialized. initialize(microseconds) īegin using the timer. If using TimerThree, replace "Timer1" with "Timer3".Ĭonfiguration Timer1. The PWM pins can also be configured to switch At the end ofĮach period, an interrupt function can be run. The timer is configured to repetitively measure a period of time, in microseconds. Pins will not work normally, but you can use the library pwm() function. While uses these libraries, analogWrite() to those TimerOne and TimerThree let you use the built-in 16 bit timers.Įach timer controls PWM pins.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |