Pullup all unused pins to minimize power consumption.

Examples/idleWakePeriodic/idleWakePeriodic.ino

@@ -3,7 +3,7 @@
 
 void setup()
 {
-  // No setup is required for this library
+  LowPower.pullupAllPins(); // This should appear before any calls to pinMode
 }
 
 void loop() 
@@ -33,4 +33,3 @@ void loop()
   // Do something here
   // Example: Read sensor, data logging, data transmission.
 }
-

Examples/powerDownWakeExternalInterrupt/powerDownWakeExternalInterrupt.ino

@@ -11,6 +11,7 @@ void wakeUp()
 
 void setup()
 {
+    LowPower.pullupAllPins(); // This should appear before any calls to pinMode
     // Configure wake up pin as input.
     // This will consumes few uA of current.
     pinMode(wakeUpPin, INPUT);   

Examples/powerDownWakePeriodic/powerDownWakePeriodic.ino

@@ -3,7 +3,7 @@
 
 void setup()
 {
-    // No setup is required for this library
+    LowPower.pullupAllPins(); // This should appear before any calls to pinMode
 }
 
 void loop() 

Examples/standbyExternalInterruptSAMD21/standbyExternalInterruptSAMD21.ino

@@ -7,6 +7,8 @@ unsigned char count = 10;
 
 void setup()
 {
+  LowPower.pullupAllPins(); // This should appear before any calls to pinMode
+
 	// Wait for serial USB port to open
 	while(!SerialUSB);
 	SerialUSB.println("***** ATSAMD21 Standby Mode Example *****");

LowPower.cpp

@@ -222,6 +222,30 @@ void	LowPowerClass::idle(period_t period, adc_t adc, timer2_t timer2,
 	if (usart0 == USART0_OFF)	power_usart0_enable();
 	if (twi == TWI_OFF)			power_twi_enable();
 }
+
+/*******************************************************************************
+* Name: pullupAllPins
+* Description: If some pins are unused, it is recommended to ensure
+* that these pins have a defined level. Even though most of the digital
+* inputs are disabled in the deep sleep mode floating inputs should be
+* avoided to reduce current consumption in all other modes where the
+* digital inputs are enabled (reset, active mode and idle mode).The
+* simplest method to ensure a defined level of an unused pin, is to
+* enable the internal pull-up. 
+*
+* Argument  	Description
+* =========  	===========
+* 1. NIL
+*
+*******************************************************************************/
+void	LowPowerClass::pullupAllPins()
+{
+	for (uint8_t i = 0; i < 23; i++)
+	{
+		pinMode(i, INPUT_PULLUP);
+	}
+
+}
 #endif
 
 /*******************************************************************************
@@ -327,6 +351,30 @@ void	LowPowerClass::idle(period_t period, adc_t adc,
 	if (twi == TWI_OFF)			power_twi_enable();
 	if (usb == USB_OFF)			power_usb_enable();
 }
+
+/*******************************************************************************
+* Name: pullupAllPins
+* Description: If some pins are unused, it is recommended to ensure
+* that these pins have a defined level. Even though most of the digital
+* inputs are disabled in the deep sleep mode floating inputs should be
+* avoided to reduce current consumption in all other modes where the
+* digital inputs are enabled (reset, active mode and idle mode).The
+* simplest method to ensure a defined level of an unused pin, is to
+* enable the internal pull-up. 
+*
+* Argument  	Description
+* =========  	===========
+* 1. NIL
+*
+*******************************************************************************/
+void	LowPowerClass::pullupAllPins()
+{
+	for (uint8_t i = 0; i < 26; i++)
+	{
+		pinMode(i, INPUT_PULLUP);
+	}
+
+}
 #endif
 
 /*******************************************************************************
@@ -449,6 +497,31 @@ void	LowPowerClass::idle(period_t period, adc_t adc, timer2_t timer2,
 	if (usart0 == USART0_OFF)	power_usart0_enable();
 	if (twi == TWI_OFF)			power_twi_enable();
 }
+
+
+/*******************************************************************************
+* Name: pullupAllPins
+* Description: If some pins are unused, it is recommended to ensure
+* that these pins have a defined level. Even though most of the digital
+* inputs are disabled in the deep sleep mode floating inputs should be
+* avoided to reduce current consumption in all other modes where the
+* digital inputs are enabled (reset, active mode and idle mode).The
+* simplest method to ensure a defined level of an unused pin, is to
+* enable the internal pull-up. 
+*
+* Argument  	Description
+* =========  	===========
+* 1. NIL
+*
+*******************************************************************************/
+void	LowPowerClass::pullupAllPins()
+{
+	for (uint8_t i = 0; i < 32; i++)
+	{
+		pinMode(i, INPUT_PULLUP);
+	}
+
+}
 #endif
 
 /*******************************************************************************
@@ -605,6 +678,30 @@ void	LowPowerClass::idle(period_t period, adc_t adc, timer5_t timer5,
 	if (usart0 == USART0_OFF)	power_usart0_enable();
 	if (twi == TWI_OFF)			power_twi_enable();
 }
+
+/*******************************************************************************
+* Name: pullupAllPins
+* Description: If some pins are unused, it is recommended to ensure
+* that these pins have a defined level. Even though most of the digital
+* inputs are disabled in the deep sleep mode floating inputs should be
+* avoided to reduce current consumption in all other modes where the
+* digital inputs are enabled (reset, active mode and idle mode).The
+* simplest method to ensure a defined level of an unused pin, is to
+* enable the internal pull-up. 
+*
+* Argument  	Description
+* =========  	===========
+* 1. NIL
+*
+*******************************************************************************/
+void	LowPowerClass::pullupAllPins()
+{
+	for (uint8_t i = 0; i < 86; i++)
+	{
+		pinMode(i, INPUT_PULLUP);
+	}
+
+}
 #endif
 
 /*******************************************************************************
@@ -749,6 +846,31 @@ void	LowPowerClass::idle(period_t period, adc_t adc, timer5_t timer5,
 	if (usart0 == USART0_OFF)	power_usart0_enable();
 	if (twi == TWI_OFF)			  power_twi_enable();
 }
+
+
+/*******************************************************************************
+* Name: pullupAllPins
+* Description: If some pins are unused, it is recommended to ensure
+* that these pins have a defined level. Even though most of the digital
+* inputs are disabled in the deep sleep mode floating inputs should be
+* avoided to reduce current consumption in all other modes where the
+* digital inputs are enabled (reset, active mode and idle mode).The
+* simplest method to ensure a defined level of an unused pin, is to
+* enable the internal pull-up. 
+*
+* Argument  	Description
+* =========  	===========
+* 1. NIL
+*
+*******************************************************************************/
+void	LowPowerClass::pullupAllPins()
+{
+	for (uint8_t i = 0; i < 38; i++)
+	{
+		pinMode(i, INPUT_PULLUP);
+	}
+
+}
 #endif
 
 

LowPower.h

@@ -152,6 +152,7 @@ class LowPowerClass
 			void	powerSave(period_t period, adc_t adc, bod_t bod, timer2_t timer2) __attribute__((optimize("-O1")));
 			void	powerStandby(period_t period, adc_t adc, bod_t bod) __attribute__((optimize("-O1")));
 			void	powerExtStandby(period_t period, adc_t adc, bod_t bod, timer2_t timer2) __attribute__((optimize("-O1")));
+			void	pullupAllPins();
 
 		#elif defined (__arm__)
 

keywords.txt

@@ -16,7 +16,8 @@ powerDown	KEYWORD2
 powerSave	KEYWORD2
 powerStandby	KEYWORD2
 powerExtStandby	KEYWORD2
-standby	KEYWORD2
+standby		KEYWORD2
+pullupAllPins	KEYWORD2
 
 #######################################
 # Instances (KEYWORD2)