Digital Signals
Drive Digital Actuators
To control a digital actuator - for example, an LED - you need two commands: The first is in the setup()
, the second in the loop()
. In the setup
-function the command pinMode(1, OUTPUT);
determines that pin 1 has something connected to it, which should be used as output (or OUTPUT). The 1 can be replaced by any other pin number, depending on which Arduino pin you have connected the actuator. The second function in the loop()
-function is digitalWrite (1, HIGH);
. Thus, the actuator connected to pin 1 is supplied with power, i.e. switched on. The counterpart to this command would be digital´Write(1, LOW);
to stop the power supply again. Again, the 1 is replaceable by any other pin number. The sketch should look like this:
void setup(){
pinMode(1,OUTPUT); //Declare the pin on which the LED
// is connected as output
}
void loop(){
digitalWrite(1,HIGH); // Turn on the LED
}
Reading Digital Sensors
The same pins we used to drive digital actuators can also be used to register input signals. Digital inputs can assume two states just like digital outputs; HIGH
or LOW
.
For incoming signals to be processed, they must be stored in variables.
To store digital signals, a Boolean variable (also called boolean
),which can take only two values, is particularly suitable. In order to read out a digital sensor, two commands are needed, similar to the control of digital sensors.
In the loop()
-function the command pinMode(1, INPUT);
sets pin 1 of the senseBox MCU as input.In the setup()
-function the command testVariable = digitalRead(1);
a sensor connected to pin 1 is read out and the value stored in the previously created test variable. Just like driving digital actuators, 1 stands for the pin used and can be replaced by any other digital pin. The sketch should look like this:
boolean testVariable = 0; // declare a new variable of thype boolean
void setup() {
pinMode(1,INPUT);
}
void loop() {
testVariable = digitalRead (1); // write the read value into the variable
}
The content of the created variable can be displayed in the serial monitor.