final firmware commit

examples/daily_alarm/daily_alarm.ino

@@ -0,0 +1,32 @@
+/*
+   Example Arduino code to trigger an alarm at 1600hrs, i.e., at 4PM everyday.
+ */
+#include "ds3231.h"
+#include <Wire.h>
+
+#define interruptpin 2
+
+class ds3231 rtc;
+volatile byte flag=false;
+
+void setup() {
+  Wire.begin();
+  pinMode(LED_BUILTIN,OUTPUT);
+  digitalWrite(LED_BUILTIN,false);
+  pinMode(interruptpin,INPUT_PULLUP);     // Setup interrupt pin
+  digitalWrite(interruptpin,true);
+  attachInterrupt(digitalPinToInterrupt(interruptpin),isr_a1,FALLING);  // setup interrupt
+  rtc.init();
+  rtc.set_alarm1(hr_min_sec_match,0x00,0x00,0x16);   // Setup alarm 1 to trigger once everyday at the given time. (0x16 due to the use of 24 hr format)
+  rtc.arm_alarm1();                                  // arm alarm 1
+}
+
+void loop() {
+  digitalWrite(LED_BUILTIN,flag);  // LED changing state indicates triggering of the alarm
+  rtc.clear_alarm1();
+}
+
+void isr_a1()
+{
+  flag=!flag;
+}

examples/sq_wave_1s/sq_wave_1s.ino

@@ -0,0 +1,32 @@
+/*
+   Example Arduino code to generate a square wave of period 1s using interrupts
+ */
+#include "ds3231.h"
+#include <Wire.h>
+
+#define interruptpin 2
+
+class ds3231 rtc;
+volatile byte flag=false;
+
+void setup() {
+  Wire.begin();
+  pinMode(LED_BUILTIN,OUTPUT);
+  digitalWrite(LED_BUILTIN,false);
+  pinMode(interruptpin,INPUT_PULLUP);     // Setup interrupt pin
+  digitalWrite(interruptpin,true);
+  attachInterrupt(digitalPinToInterrupt(interruptpin),isr_a1,FALLING);  // setup interrupt
+  rtc.init();
+  rtc.set_alarm1(every_second);     // set alarm 1 to trigger once every second
+  rtc.arm_alarm1();                 // arm alarm 1
+}
+
+void loop() {
+  digitalWrite(LED_BUILTIN,flag);  // LED changing state indicates triggering of the interrupt
+  rtc.clear_alarm1();
+}
+
+void isr_a1()
+{
+  flag=!flag;
+}

ds3231.cpp → src/ds3231.cpp

@@ -25,13 +25,13 @@ uint8_t ds3231::init()
 	//Wire.begin();       // ***NOTE: Uncomment this line if the RTC is the only I2C device in use. Else, call Wire.begin() in the setup function***
 	// ***NOTE: It is always advisable to intialise the I2C bus (by calling Wire.begin()) in the setup function***
 	write8(control,0x04);
-	set_year(0x19);
-	set_month(0x07);
-	set_date(0x02);
-	set_day(tuesday);
-	set_hours(0,0x20);
-	write8(minutes,0x59);
-	write8(seconds,0x55);
+	set_year(0x19);          // Initialise year to 2019
+	set_month(0x07);         // Initialise month to July
+	set_date(0x01);          // Initialise date to 01
+	set_day(monday);         // Initialise day of the week to Monday
+	set_hours(0,0x00);       // Initialise hours to 00 (midnight)
+	write8(minutes,0x00);    // Initialise minutes to 00
+	write8(seconds,0x00);    // Initialise seconds to 00
 	return 0;
 }