Initializer Lists - TeensyUser/doc GitHub Wiki
If you have a class with a default constructor (parameter less constructor) you can easily declare arrays of objects of this class. Here an example showing how to do this with Servos
#include "Servo.h"
Servo servos[5]; // array of 5 Servo objects
void setup()
{
servos[0].attach(3); // attach pins to the Servos
servos[1].attach(7);
//...
}However, if the constructor of your class needs parameters you need to pass them as shown below for the Encoder class. The Encoder constructor requires two pin numbers for phase A and phase B respectively.
#include "Encoder.h"
Encoder encoders[]{{1,2}, {4,7}, {0,15}}; // constructs 3 encoders at pins (1,2), (4,7) and (0,15)
constexpr int nrOfEncoders = sizeof(encoders) / sizeof(encoders[0]);
void setup(){}
void loop()
{
for (int i = 0; i < nrOfEncoders; i++)
{
Serial.println(encoders[i].read());
}
delay(200);
}
Initializer lists can be useful if you need to do something for a list of arbitrary objects. The following example shows how to set the pinMode of a bunch of pins to output:
void setup()
{
constexpr uint8_t pinA = 3, LED = 13, STP = 7;
for(uint8_t pin : {pinA, LED, STP}) // for each pin in the initializer list
{
pinMode(pin, OUTPUT);
}
}You can also use initializer lists as parameters to functions. Let's define a enhancement for the pinMode function which takes a list of pins instead of only one.
void pinMode(std::initializer_list<uint8_t> pins, uint8_t mode){
for(uint8_t pin : pins){
pinMode(pin, mode);
}
}
// usage:
void setup(){
constexpr uint8_t pinA = 3, LED = 13, STP = 7;
pinMode({pinA, LED, STP}, OUTPUT);
}