Battery service (#53)

* Added read battery capacity function

* Added battery service example

Author: DHJeff

libraries/BAT/bat.cpp

@@ -62,3 +62,16 @@ double bat::analogRead(void) {
 
 	return voltage;
 }
+
+int bat::capacity(void) {
+    double calculate_voltage;
+    double get_voltage;
+	int capacity;
+	get_voltage = analogRead();
+	calculate_voltage = get_voltage - 2.9;
+	capacity = calculate_voltage / 0.0124;
+	if (capacity > 100)
+    capacity = 100;
+
+  	return capacity;
+}

libraries/BAT/bat.h

@@ -41,6 +41,7 @@ class bat {
 public:
 	bat(void);
 	double analogRead(void);
+  int capacity(void);
 private:
 	uint8_t recBuffer[REC_BUF_LENGTH];
 

libraries/BAT/examples/BatteryServicePeripheral/BatteryServicePeripheral.ino

@@ -0,0 +1,81 @@
+/*
+  BatteryServicePeripheral.ino
+  Written by  Chiara Ruggeri (chiara@arduino.org)
+              Jeff Wu (jeff@arduino.org)
+
+  This example shows how to read a characteristic to get battery capacity of Primo board
+  Disabling STM32 enter to standby mode when Primo board is powered only by battery.
+  You can use nRFConnect app to read the characteristic
+  https://www.nordicsemi.com/eng/Products/Nordic-mobile-Apps/nRF-Connect-for-mobile-previously-called-nRF-Master-Control-Panel
+
+  In this example allows you to get battery capacity of Primo board. It will blink every 200 ms when the board is advertising.
+  It will be on when the board is connected to a central. It will be off when the board is disconnected.
+
+  This example code is in the public domain.
+*/
+
+#include <BLEPeripheral.h>
+#include <stm32pwr.h>
+#include <bat.h>
+
+// create peripheral instance
+BLEPeripheralRole        blePeripheral        = BLEPeripheralRole();
+
+// create service
+BLEService               batteryService       = BLEService("180F");
+
+// create battery level characteristic
+BLECharCharacteristic    batLevelChar         = BLECharCharacteristic("2A19", BLERead | BLENotify);
+
+bat primo_bat;
+
+void setup() {
+  // start serial port at 9600 bps
+  Serial.begin(9600);
+
+  // disable STM32 enter to standby mode
+  stm32pwr.disableStandbyMode();
+
+  // initialize BLE led
+  pinMode(BLE_LED, OUTPUT);
+
+  // set advertised local name and service UUID
+  blePeripheral.setLocalName("Battery information");
+  blePeripheral.setAdvertisedServiceUuid(batteryService.uuid());
+
+  // add service and characteristic
+  blePeripheral.addAttribute(batteryService);
+  blePeripheral.addAttribute(batLevelChar);
+
+  // begin initialization
+  blePeripheral.begin();
+
+  Serial.println(F("BLE Battery Service Peripheral"));
+}
+
+void loop() {
+  // retrieve the peripheral status in order to blink only when advertising
+  if(blePeripheral.status() == ADVERTISING){
+    digitalWrite(BLE_LED, LOW);
+    delay(200);
+    digitalWrite(BLE_LED, HIGH);
+    delay(200);
+  }
+  else{ // if we are not advertising, we are connected
+    double bat_voltage;
+    // get battery voltage value
+    bat_voltage = primo_bat.analogRead();
+    // print battery voltage vaule on serial port
+    Serial.print("Battery Voltage:" );
+    Serial.println(bat_voltage,3);
+  
+    int bat_capacity;
+    digitalWrite(BLE_LED, HIGH);
+    // get battery capacity
+    bat_capacity = primo_bat.capacity();
+    // retrieve battery level and update the characteristic
+    batLevelChar.setValue(bat_capacity);
+    Serial.println(bat_capacity);
+    delay(1000);
+  }
+}

libraries/BAT/keywords.txt

@@ -13,6 +13,7 @@ bat	KEYWORD1
 #######################################
 
 analogRead	KEYWORD2
+capacity	KEYWORD2
 
 #######################################
 # Constants (LITERAL1)