Wiring Base

• abs()
• analogRead()
• analogWrite()
• cos()
• delay()
• delayMicroseconds()
• digitalRead()
• digitalWrite()
• millis
• PinMode()
• pow()
• randomSeed
• sin()
• sqrt()
• tan()

abs()

The abs() function returns the absolute value of a floating point number.

Syntax

abs(x);  //(P8 and P32)

Parameters

Param	Type	Desc
x	float	floating point number

Returns

The absolute value of x.

Example

Notes

Relates

• pow()
• sin()
• cos()
• tan()
• sqrt()

analogRead()

The analogRead() function reads the value on an analog pin to 10 bits resolution.

Syntax

analogRead(pin);  //(P8 and P32)

Parameters

Param	Type	Desc
pin	integer	The pin number to read.

Returns

Returns a value proportional to the voltage applied on the selected pin: 0..5v (P8), 0..3.3v (P32).

Example

// level detector (P8) by J P Mandon
 
int level;
 
void setup()
{
pinMode(0,OUTPUT);
digitalWrite(0,LOW);
}
 
void loop()
{
level=analogRead(13);
if (level>512) digitalWrite(0,HIGH);  // if voltage applied on pin 13 > 2.5V set pin 0 HIGH
else digitalWrite(0,LOW);             // else reset pin 0 LOW
}

Notes

IDE defined 'pins' that can read an analog value depend on the device. Typically, if one pin is used as analog input, all remaining analog pins are configured as analog inputs. See Pinguino Boards page for details of pin mapping. NB - exceeding an input voltage of 5v (P8) or 3.3v (P32) is likely to destroy the device.

Relates

• analogWrite()

analogWrite()

The analogWrite() function sets an analog signal on a pin via pulse width modulation (PWM).

Syntax

analogWrite(pin,value);  //(P8 and P32)

Parameters

Param	Type	Desc
pin	integer	The pin number to write.
value	integer	Value between 0 and 1023

Returns

None

Example

void setup()
{
}
 
void loop()
{
        analogWrite(11,512);    // 50% PWM on pin 11
        analogWrite(12,102);    // 10% PWM on pin 12
}

Notes

The voltage that appears on a pin using this function is pulse width modulated i.e. a square wave. An integrator must be utilised if a DC signal is required. Following integration, if value is e.g. 1023 then the nominal DC voltage will be 5v (P8) or 3.3v (P32).

Relates

• analogRead()

cos()

The cos() function returns the cosine of parameter x, where x is given in radians (2π radians = 360 degrees).

Syntax

cos(x);  //(P8 and P32)

Parameters

Param	Type	Desc
x	float	floating point number

Returns

The cosine of x.

Example

Notes

Relates

• abs()
• pow()
• sin()
• tan()
• sqrt()

delay()

The delay() function instructs the processor to wait for a specified period of time in milliseconds.

Syntax

delay(x);  //(P8 and P32)

Parameters

Param	Type	Desc
x	unsigned long	Duration in milliseconds.

Returns

none

Example

Notes

Relates

• delayMicroseconds()

delayMicroseconds()

The delayMicroseconds() function instructs the processor to wait for a specified period of time in microseconds.

Syntax

delayMicroseconds(x);  //(P8 and P32)

Parameters

Param	Type	Desc
x	unsigned integer	Duration in microseconds.

Returns

none

Example

Notes

Relates

• delay()

digitalRead()

The digitalRead() function reads the value of a digital input pin. Possible values are HIGH or LOW.

Syntax

digitalRead(pin);  //(P8 and P32)

Parameters

Param	Type	Desc
pin	integer	The pin number to read.

Returns

The voltage level of the pin - LOW corresponds to a level nominally 0 volts (P8 and P32); HIGH corresponds to a level nominally 5v (P8) or 3.3v (P32).

Example

// Testing input by J P Mandon
 
void setup()
{
        pinMode(1,INPUT);
        pinMode(7,OUTPUT);
}
 
void loop()
{
        if (digitalRead(1)) 
                digitalWrite(7,HIGH);
        else 
                digitalWrite(7,LOW);
}

Notes

The parameter pin refers to the IDE defined 'pin', which typically differs from the device physical pin. See Pinguino Boards page for details of pin mapping. The relevant pin should be configured as input using pinMode().

Relates

• INPUT
• OUTPUT
• HIGH
• LOW
• digitalWrite()
• pinMode()

digitalWrite()

The digitalWrite() function sets the value of a digital output pin. Possible values are HIGH or LOW.

Syntax

digitalWrite(pin,value);  //(P8 and P32)

Parameters

Param	Type	Desc
pin	integer	The pin number to write.
value	constant	Can be HIGH or LOW.

Returns

None

Example

int outpin = 8;

void setup() {
  pinMode(outpin, OUTPUT); 
}

void loop() {
  digitalWrite(outpin, HIGH);
}

Notes

The parameter pin refers to the IDE defined 'pin', which typically differs from the device physical pin. See Pinguino Boards page for details of pin mapping. The parameter LOW sets the pin nominally to 0 volts (P8 and P32). The parameter HIGH sets the pin nominally to 5 volts (P8) or 3.3 volts (P32).

Relates

• INPUT
• OUTPUT
• HIGH
• LOW
• digitalRead()
• pinMode()

millis

The millis() function returns the time elapsed since the beginning of the program.

Syntax

millis();  //(P8 and P32)

Parameters

none

Returns

Returns the time elapsed in milliseconds since the start of the user program. This value is a long integer (32 bits). To reset the counter use _millis = 0;

Example

void setup()
{
pinMode(0,OUTPUT);
digitalWrite(0,LOW);
}
 
void loop()
{
if (millis()>1000) digitalWrite(0,HIGH);  // light the led after 1 second
 
if (millis()>2000) _millis=0;  // reset the millis() counter after 2 seconds
}

Notes

At the beginning of the program, internal timer TMR0 is initialized to zero. It is a 16 bit integer value incremented every millisecond. The millis() function returns the current value of TMR0.

Relates

PinMode()

The pinMode() function configures a given pin as input or output.

Syntax

pinMode(pin,mode); //(P8 and P32)

Parameters

Param	Type	Desc
pin	integer	The pin number to write.
mode	constant	Can be INPUT or OUTPUT.

Returns

none

Example

// Testing input J P Mandon

int led1;
int led2;
 
void setup()
{
        led1=1;
        led2=7;
        pinMode(led1,OUTPUT);
        pinMode(led2,OUTPUT);
}
 
void loop()
{
        digitalWrite(led1,HIGH);
        digitalWrite(led2,LOW);
        delay(500);
        digitalWrite(led1,LOW);
        digitalWrite(led2,HIGH);
        delay(500);
}

Notes

Relates

• digitalRead()
• digitalWrite()

pow()

The pow() function returns the value of x raised to the power y.

Syntax

pow(x,y);  //(P8 and P32)

Parameters

Param	Type	Desc
x	float	floating point number
y	float	floating point number

Returns

The value of x to the power y.

Example

Notes

Relates

• abs()
• sin()
• cos()
• tan()
• sqrt()

randomSeed

The randomSeed() function sets its argument as the seed for the sequence of pseudo-random integers returned by the associated function rand().

Syntax

randomSeed(seed); //(P8 and P32)
rand();

Parameters

Param	Type	Desc
seed	unsigned integer	Random seed value

Returns

None

Example

// Blink an LED attached to pin 11 for random periods
#define MYLED 11
 
// Time to sleep
unsigned short pause;
 
void setup(void)
{
        pinMode(MYLED,OUTPUT);
        // Init random generator with a fixed random value
	randomSeed(55);
}
 
void loop(void)
{
        // Pause is between 0 and 0b111 (7 in decimal)
	pause = rand() & 0x007;
        // Light ON
        digitalWrite(MYLED,HIGH);
        // delay is between 200ms and 1.6s
        delay(200 * (pause + 1));
        // Light off
        digitalWrite(MYLED,LOW);
        // Delay 200ms
        delay(200);
}

Notes

A fixed seed will repeatedly generate the same pseudo-random number sequence. Thus, randomseed() should be called with a value determined by an external event if a different sequence is required on subsequent runs. The function rand() returns a pseudo-random number in the range 0...32767.

Relates

sin()

The sin() function returns the sine of parameter x, where x is given in radians (2π radians = 360 degrees).

Syntax

sin(x);  //(P8 and P32)

Parameters

Param	Type	Desc
x	float	floating point number

Returns

The sine of x.

Example

Notes

Relates

• abs()
• pow()
• cos()
• tan()
• sqrt()

sqrt()

The sqrt() function returns the (non-negative) square root of parameter x.

Syntax

sqrt(x);  //(P8 and P32)

Parameters

Param	Type	Desc
x	float	floating point number

Returns

The square root of x.

Example

Notes

Relates

• abs()
• pow()
• sin()
• tan()
• cos()

tan()

The tan() function returns the tangent of parameter x, where x is given in radians (2π radians = 360 degrees).

Syntax

tan(x);  //(P8 and P32)

Parameters

Param	Type	Desc
x	float	floating point number

Returns

The tangent of x.

Example

Notes

Relates

• abs()
• pow()
• sin()
• cos()
• sqrt()