Arduino入門：アナログ入出力関数

//Arduino Sketch Example: analogRead
//Date: 2015.1.12
//Edited and Modified by: easy labo
//Original Source: Arduino Reference (http://arduino.cc/en/Reference/HomePage)

//Syntax
analogRead(pin)

//pin: the number of the analog input pin to read from 
//(0 to 5 on most boards, 0 to 7 on the Mini and Nano, 0 to 15 on the Mega)
//Returns: int (0 to 1023)

//Example
int analogPin = 3;  // potentiometer wiper (middle terminal) connected to analog pin 3  // outside leads to ground and +5V
int val = 0;  // variable to store the value read

void setup()
{
  Serial.begin(9600);  //  setup serial
}

void loop()
{
  val = analogRead(analogPin);  // read the input pin
  Serial.println(val);  // debug value
}

//Arduino Sketch Example: analogWrite
//Date: 2015.1.12
//Edited and Modified by: easy labo
//Original Source: Arduino Reference (http://arduino.cc/en/Reference/HomePage)

//Syntax
analogWrite(pin, value)

//pin: the pin to write to.
//value: the duty cycle: between 0 (always off) and 255 (always on).

//Example
int ledPin = 9;    // LED connected to digital pin 9
int analogPin = 3; // potentiometer connected to analog pin 3
int val = 0;       // variable to store the read value

void setup()
{
   pinMode(ledPin, OUTPUT);   // sets the pin as output
}

void loop()
{
   val = analogRead(analogPin);   // read the input pin
   analogWrite(ledPin, val / 4);  // analogRead values go from 0 to 1023, analogWrite values from 0 to 255
}

//Arduino Sketch Example: analogReference
//Date: 2015.1.12
//Edited and Modified by: easy labo
//Original Source: Arduino Reference (http://arduino.cc/en/Reference/HomePage)

//Syntax
analogReference(type)

//type: which type of reference to use (DEFAULT, INTERNAL, INTERNAL1V1, INTERNAL2V56, or EXTERNAL).

//Arduino Sketch Example: analogReadResolution
//Date: 2015.1.12
//Edited and Modified by: easy labo
//Original Source: Arduino Reference (http://arduino.cc/en/Reference/HomePage)

//Syntax
analogReadResolution(bits)

//bits: determines the resolution (in bits) of the value returned by analogRead() function. You can set this 1 and 32. 
//You can set resolutions higher than 12 but values returned by analogRead() will suffer approximation. 
//See the note below for details.

//Example
void setup() {
  // open a serial connection
  Serial.begin(9600); 
}

void loop() {
  // read the input on A0 at default resolution (10 bits)
  // and send it out the serial connection 
  analogReadResolution(10);
  Serial.print("ADC 10-bit (default) : ");
  Serial.print(analogRead(A0));

  // change the resolution to 12 bits and read A0
  analogReadResolution(12);
  Serial.print(", 12-bit : ");
  Serial.print(analogRead(A0));

  // change the resolution to 16 bits and read A0
  analogReadResolution(16);
  Serial.print(", 16-bit : ");
  Serial.print(analogRead(A0));

  // change the resolution to 8 bits and read A0
  analogReadResolution(8);
  Serial.print(", 8-bit : ");
  Serial.println(analogRead(A0));

  // a little delay to not hog serial monitor
  delay(100);
}

//Arduino Sketch Example: analogWriteResolution
//Date: 2015.1.12
//Edited and Modified by: easy labo
//Original Source: Arduino Reference (http://arduino.cc/en/Reference/HomePage)

//Syntax
analogWriteResolution(bits)

//bits: determines the resolution (in bits) of the values used in the analogWrite() function. 
//The value can range from 1 to 32. If you choose a resolution higher or lower than your board's hardware capabilities,
//the value used in analogWrite() will be either truncated if it's too high or padded with zeros if it's too low. See the note below for details.

void setup(){
  // open a serial connection
  Serial.begin(9600); 
  // make our digital pin an output
  pinMode(11, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(13, OUTPUT);
}

void loop(){
  // read the input on A0 and map it to a PWM pin
  // with an attached LED
  int sensorVal = analogRead(A0);
  Serial.print("Analog Read) : ");
  Serial.print(sensorVal);

  // the default PWM resolution
  analogWriteResolution(8);
  analogWrite(11, map(sensorVal, 0, 1023, 0 ,255));
  Serial.print(" , 8-bit PWM value : ");
  Serial.print(map(sensorVal, 0, 1023, 0 ,255));

  // change the PWM resolution to 12 bits
  // the full 12 bit resolution is only supported
  // on the Due
  analogWriteResolution(12);
  analogWrite(12, map(sensorVal, 0, 1023, 0, 4095));
  Serial.print(" , 12-bit PWM value : ");
  Serial.print(map(sensorVal, 0, 1023, 0, 4095));

  // change the PWM resolution to 4 bits
  analogWriteResolution(4);
  analogWrite(13, map(sensorVal, 0, 1023, 0, 127));
  Serial.print(", 4-bit PWM value : ");
  Serial.println(map(sensorVal, 0, 1023, 0, 127));

  delay(5);
}