adding sense functions and sleep example

Author: jpconstantineau

cores/nRF5/wiring_constants.h

@@ -30,6 +30,8 @@ extern "C"{
 #define OUTPUT          (0x1)
 #define INPUT_PULLUP    (0x2)
 #define INPUT_PULLDOWN  (0x3)
+#define INPUT_PULLUP_SENSE    (0x4)
+#define INPUT_PULLDOWN_SENSE  (0x5)
 
 #define PI 3.1415926535897932384626433832795
 #define HALF_PI 1.5707963267948966192313216916398

cores/nRF5/wiring_digital.c

@@ -55,6 +55,15 @@ void pinMode( uint32_t ulPin, uint32_t ulMode )
                            | ((uint32_t)GPIO_PIN_CNF_DRIVE_S0S1       << GPIO_PIN_CNF_DRIVE_Pos)
                            | ((uint32_t)GPIO_PIN_CNF_SENSE_Disabled   << GPIO_PIN_CNF_SENSE_Pos);
     break;
+    
+    case INPUT_PULLUP_SENSE:
+      // Set pin to input mode with pull-up resistor enabled and sense when Low
+      port->PIN_CNF[ulPin] = ((uint32_t)GPIO_PIN_CNF_DIR_Input        << GPIO_PIN_CNF_DIR_Pos)
+                           | ((uint32_t)GPIO_PIN_CNF_INPUT_Connect    << GPIO_PIN_CNF_INPUT_Pos)
+                           | ((uint32_t)GPIO_PIN_CNF_PULL_Pullup      << GPIO_PIN_CNF_PULL_Pos)
+                           | ((uint32_t)GPIO_PIN_CNF_DRIVE_S0S1       << GPIO_PIN_CNF_DRIVE_Pos)
+                           | ((uint32_t)GPIO_PIN_CNF_SENSE_Low        << GPIO_PIN_CNF_SENSE_Pos);
+    break;
 
     case INPUT_PULLDOWN:
       // Set pin to input mode with pull-down resistor enabled
@@ -65,6 +74,15 @@ void pinMode( uint32_t ulPin, uint32_t ulMode )
                            | ((uint32_t)GPIO_PIN_CNF_SENSE_Disabled   << GPIO_PIN_CNF_SENSE_Pos);
     break;
 
+    case INPUT_PULLDOWN_SENSE:
+      // Set pin to input mode with pull-down resistor enabled
+      port->PIN_CNF[ulPin] = ((uint32_t)GPIO_PIN_CNF_DIR_Input        << GPIO_PIN_CNF_DIR_Pos)
+                           | ((uint32_t)GPIO_PIN_CNF_INPUT_Connect    << GPIO_PIN_CNF_INPUT_Pos)
+                           | ((uint32_t)GPIO_PIN_CNF_PULL_Pulldown    << GPIO_PIN_CNF_PULL_Pos)
+                           | ((uint32_t)GPIO_PIN_CNF_DRIVE_S0S1       << GPIO_PIN_CNF_DRIVE_Pos)
+                           | ((uint32_t)GPIO_PIN_CNF_SENSE_High       << GPIO_PIN_CNF_SENSE_Pos);
+    break;
+
     case OUTPUT:
       // Set pin to output mode
       port->PIN_CNF[ulPin] = ((uint32_t)GPIO_PIN_CNF_DIR_Output       << GPIO_PIN_CNF_DIR_Pos)

libraries/Bluefruit52Lib/examples/Hardware/blink_sleep/blink_sleep.ino

@@ -0,0 +1,47 @@
+/*
+  Blink_sleep
+  Turns on an LED on for one second, then off for one second, until the time to go to sleep runs out.
+
+  Based on the blinky arduino example 
+  
+  This example code is in the public domain.
+
+  modified 19 Jan 2010
+  by Pierre Constantineau
+
+*/
+
+#define WAKE_LOW_PIN  PIN_A0
+#define WAKE_HIGH_PIN PIN_A1
+
+#define SLEEPING_DELAY 30000                                // sleep after 30 seconds of blinking
+
+void gotoSleep(unsigned long time)
+{
+  // shutdown when time reaches SLEEPING_DELAY ms
+  if ((time>SLEEPING_DELAY))
+  {
+    // to reduce power consumption when sleeping, turn off all your LEDs (and other power hungry devices)
+    digitalwrite(LED_BUILTIN, LOW);                     
+
+    // setup your wake-up pins.
+    pinModeSense(WAKE_LOW_PIN,  INPUT_PULLUP_SENSE);    // this pin (WAKE_LOW_PIN) is pulled up and wakes up the feather when externally connected to ground.
+    pinModeSense(WAKE_HIGH_PIN, INPUT_PULLDOWN_SENSE);  // this pin (WAKE_HIGH_PIN) is pulled down and wakes up the feather when externally connected to 3.3v.
+ 
+    // power down nrf52.
+    sd_power_system_off();                              // this function puts the whole nRF52 to deep sleep (no Bluetooth).  If no sense pins are setup (or other hardware interrupts), the nrf52 will not wake up.
+  } 
+}
+
+// the setup function runs once when you press reset or power the board
+void setup() {
+  // initialize digital pin LED_BUILTIN as an output.
+  pinMode(LED_BUILTIN, OUTPUT);
+}
+     
+// the loop function runs over and over again forever
+void loop() {
+  digitalToggle(LED_BUILTIN); // turn the LED on (HIGH is the voltage level)
+  gotoSleep(millis());        // call millis() and pass it to the sleep function.  On wake-up, millis will start at 0 again.
+  delay(1000);                // wait for a second
+}