In the tenth chapter, we briefly mentioned the blue
pin and the pulse data type.
This type is very different from all the others. All values in the XOD are transferred to the links continuously, even if the values haven’t changed. The pulse data type is different. Imagine something like a flash. It’s basically a message to trigger something else. It does not transmit any data. However, it is useful when you need to convey that an event has occurred or tell something else to work.
For example, say you only want an
pot node to receive information from a board
port at certain intervals, and not all the time. This frequency can be set with
the help of pulses.
Each time a pulse arrives on the
UPD pin, the node reads the analog port and
outputs the value to the
VAL pin. This value will be stored there until it
changes to another value.
The same is for the
servo. It will send the updated value to the hardware only
when receives a pulse to
The behavior of the
UPD pin can also be set in the Inspector. For a pot the
Never: Never produce pulses. That is, do not take readings or make updates at all.
On boot: Generate a pulse once at startup. Updates the state exactly once.
Continuously: Generate pulses constantly, i.e. take the readings or make updates with the highest possible rate.
Turn the potentiometer knob and press the reset button on the board itself. Note, the potentiometer updates now only once when the Arduino is turned on.