Add support of MCU sleep

Adafruit_BLE_UART.cpp

@@ -159,6 +159,7 @@ Adafruit_BLE_UART::Adafruit_BLE_UART(int8_t req, int8_t rdy, int8_t rst)
 
   rx_event = NULL;
   aci_event = NULL;
+  sleep_cb = NULL;
 
   memset(device_name, 0x00, 8);
 
@@ -175,6 +176,10 @@ void Adafruit_BLE_UART::setRXcallback(rx_callback rxEvent) {
   rx_event = rxEvent;
 }
 
+void Adafruit_BLE_UART::setSLEEPcallback(sleep_callback scb){
+  sleep_cb = scb;
+}
+
 /**************************************************************************/
 /*!
     Transmits data out via the TX characteristic (when available)
@@ -458,6 +463,7 @@ void Adafruit_BLE_UART::pollACI()
     // No event in the ACI Event queue and if there is no event in the ACI command queue the arduino can go to sleep
     // Arduino can go to sleep now
     // Wakeup from sleep from the RDYN line
+    if (sleep_cb) sleep_cb();
   }
 }
 

Adafruit_BLE_UART.h

@@ -35,6 +35,8 @@ extern "C"
   /* Callback prototypes */
   typedef void (*aci_callback)(aci_evt_opcode_t event);
   typedef void (*rx_callback) (uint8_t *buffer, uint8_t len);
+  typedef void (*sleep_callback)(void);
+
 }
 
 class Adafruit_BLE_UART : public Stream
@@ -55,6 +57,8 @@ class Adafruit_BLE_UART : public Stream
 
   void setACIcallback(aci_callback aciEvent = NULL);
   void setRXcallback(rx_callback rxEvent = NULL);
+  void setSLEEPcallback(sleep_callback sleepCb = NULL);
+
   void setDeviceName(const char * deviceName);
 
   // Stream compatibility
@@ -71,7 +75,8 @@ class Adafruit_BLE_UART : public Stream
 
   // callbacks you can set with setCallback function for user extension
   aci_callback aci_event;
-  rx_callback  rx_event; 
+  rx_callback  rx_event;
+  sleep_callback sleep_cb;
 
   bool         debugMode;
   uint16_t     adv_timeout;

examples/powersave/powersave.ino

@@ -0,0 +1,102 @@
+/*********************************************************************
+This is an example for our nRF8001 Bluetooth Low Energy Breakout with MCU being sleeping most of the time.
+
+Written by Amitesh Singh/ami <singh.amitesh@gmail.com>
+
+MIT license, check LICENSE for more information
+All text above, and the splash screen below must be included in any redistribution
+*********************************************************************/
+#include <avr/power.h>
+#include <avr/sleep.h>
+
+#include <SPI.h>
+#include "Adafruit_BLE_UART.h"
+
+// Connect CLK/MISO/MOSI to hardware SPI
+// e.g. On UNO & compatible: CLK = 13, MISO = 12, MOSI = 11
+#define ADAFRUITBLE_REQ 10
+#define ADAFRUITBLE_RDY 2     // This should be an interrupt pin, on Uno thats #2 or #3
+#define ADAFRUITBLE_RST 9
+
+Adafruit_BLE_UART BTLEserial = Adafruit_BLE_UART(ADAFRUITBLE_REQ, ADAFRUITBLE_RDY, ADAFRUITBLE_RST);
+
+volatile void powerDownSleep()
+{
+  Serial.println("Arduino: Sleep");
+  Serial.flush();
+  delay(5);
+
+  set_sleep_mode (SLEEP_MODE_PWR_DOWN);
+  sleep_enable();
+  sleep_mode();
+
+  sleep_disable();
+
+  Serial.println("Arduino: Woke up");
+}
+
+
+/**************************************************************************/
+/*!
+    Configure the Arduino and start advertising with the radio
+*/
+/**************************************************************************/
+void setup(void)
+{
+  Serial.begin(9600);
+  while(!Serial); // Leonardo/Micro should wait for serial init
+  Serial.println(F("nRF8001 powersave"));
+
+  BTLEserial.setDeviceName("BLE"); /* 7 characters max! */
+  BTLEserial.setSLEEPcallback(powerDownSleep);
+  // 1s interval, 9uA current usage
+  if (!BTLEserial.begin(0, 1600))
+  {
+    Serial.println(F("Couldn't find nRF8001, check wiring?"));
+  }
+}
+
+/**************************************************************************/
+/*!
+    Constantly checks for new events on the nRF8001
+*/
+/**************************************************************************/
+aci_evt_opcode_t laststatus = ACI_EVT_DISCONNECTED;
+
+void loop()
+{
+  // Tell the nRF8001 to do whatever it should be working on.
+  BTLEserial.pollACI();
+
+  // Ask what is our current status
+  aci_evt_opcode_t status = BTLEserial.getState();
+  // If the status changed....
+  if (status != laststatus) {
+    // print it out!
+    if (status == ACI_EVT_DEVICE_STARTED) {
+        Serial.println(F("* Advertising started"));
+    }
+    if (status == ACI_EVT_CONNECTED) {
+        Serial.println(F("* Connected!"));
+    }
+    if (status == ACI_EVT_DISCONNECTED) {
+        Serial.println(F("* Disconnected or advertising timed out"));
+    }
+    // OK set the last status change to this one
+    laststatus = status;
+  }
+
+  if (status == ACI_EVT_CONNECTED) {
+    // Lets see if there's any data for us!
+    if (BTLEserial.available()) {
+      Serial.print("* "); Serial.print(BTLEserial.available()); Serial.println(F(" bytes available from BTLE"));
+    }
+    // OK while we still have something to read, get a character and print it out
+    while (BTLEserial.available()) {
+      char c = BTLEserial.read();
+      Serial.print(c);
+    }
+  }
+  Serial.flush();
+  delay(10);
+}