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What is the interrupt number on the Arduino Uno?
It returns the appropriate interrupt number, or NOT_AN_INTERRUPT (-1). For example, on the Uno, pin D2 on the board is interrupt 0 (INT0_vect from the table below). However the second one is easier to read and more portable to different Arduino types.
How to define the exact type of interrupt you want?
That defines the exact type of interrupt you want: 0: The low level of INT0 generates an interrupt request (LOW interrupt). 1: Any logical change on INT0 generates an interrupt request (CHANGE interrupt). 2: The falling edge of INT0 generates an interrupt request (FALLING interrupt).
How are low level interrupts used in Arduino?
A rising, falling, or low-level interrupt can be used to wake up a gadget (eg. if you press a button on it), or a “watchdog timer” interrupt might wake it up periodically (eg. to check the time or temperature). Pin-change interrupts could be used to wake the processor if a key is pressed on a keypad, or similar.
How does an interrupt work in a processor?
Most processors have interrupts. Interrupts let you respond to “external” events while doing something else. For example, if you are cooking dinner you may put the potatoes on to cook for 20 minutes. Rather than staring at the clock for 20 minutes you might set a timer, and then go watch TV.
Where are the serial pins on the Arduino Uno?
SCK (Serial Clock) – A clock signal generated by the Master device to synchronize data transmission. I2C – SCL/SDA pins are the dedicated pins for I2C communication. On the Arduino Uno they are found on Analog pins A4 and A5.
How does an interrupt service routine work on Arduino?
Interrupt Service Routines are functions with no arguments. Some Arduino libraries are designed to call your own functions, so you just supply an ordinary function (as in the examples above), eg. In this case you use the “ISR” macro, and supply the name of the relevant interrupt vector (from the table earlier on).
How are voltages determined on an Arduino Uno?
On the Arduino, When the digital pins are configured as output, they are set to 0 or 5 volts. When the digital pins are configured as input, the voltage is supplied from an external device. This voltage can vary between 0-5 volts which is converted into digital representation (0 or 1). To determine this, there are 2 thresholds: