From cb6acff07379a0a97c840a800cb170414ae20ad9 Mon Sep 17 00:00:00 2001
From: William Harrington <kb0iic@berzerkula.org>
Date: Thu, 8 Aug 2019 02:19:52 -0500
Subject: Add ability when user doesn't change any date/time elemnts that the
 RTC is not updated.

---
 main.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++--------
 1 file changed, 50 insertions(+), 8 deletions(-)

diff --git a/main.c b/main.c
index 24c19fc..a30fd28 100755
--- a/main.c
+++ b/main.c
@@ -105,11 +105,11 @@ void main(void) {
      * Set an initial date time via initial program variables
      * Currently 00:00:00 1/1/00 and Sunday (day of week as 1)
      */
-    
+
     //Set_Time();
     //Set_Date();
     //Set_DayOfWeek(Get_DayOfWeek(year, month, date));
-    
+
     /*
      * isr expects 1Hz clock from RTC. This will update clock each second
      * While interrupted, clock is updating and set button will be ignored.
@@ -235,18 +235,21 @@ void format_Temperature() {
 }
 
 // Determine Alarm status from control register 0Fh bits 0 (A1F) and 1 (A2F)
+
 void Get_Alarm_Status() {
     alarm1_status = control_reg & 0x01; // Read alarm1 A1F bit
     alarm2_status = (control_reg >> 1) & 0x01; // Read alarm2 A2F bit
 }
 
 // Separate data into tens and ones units to display with character displays
+
 void display_Digit(unsigned int data) {
     Lcd_Write_Char(MSB(data));
     Lcd_Write_Char(LSB(data));
 }
 
 // Provides the user program info on startup
+
 void display_Intro() {
     // Give an intro message on the LCD
     Lcd_Clear();
@@ -332,6 +335,10 @@ void update_Display() {
  * edit flag is cleared and clock continues as normal. Sets :'s to display for
  * time in case they were blanked.
  * 
+ * Change detection variables are set before values are changed and compared
+ * as user goes through fields. If a change is detected then updateRTC flag is
+ * enabled causing the RTC to be updated.
+ * 
  * As month/date is selected, functions determine if year is leap or not,
  * the max number of days in each month, and displays the day of the week.
  * ex: 29/02/2020 is Sat and leap year with max date to select in Feb as 29.
@@ -341,6 +348,18 @@ void update_Display() {
  */
 
 void edit_Date_Time(void) {
+    // Variable to determine if RTC is updated or not (date/time valus change)
+    int updateRTC = 0;
+
+    // Variables set to current edit value and if a mismatch from user input
+    // then updateRTC is set to 1 and RTC will be updated
+    unsigned int hour_org = hour;
+    unsigned int min_org = min;
+    unsigned int sec_org = sec;
+    unsigned int year_org = year;
+    unsigned int month_org = month;
+    unsigned int date_org = date;
+
     Lcd_Set_Cursor(2, 16);
     Lcd_Write_Char('S');
     edit_datetime++;
@@ -377,7 +396,10 @@ void edit_Date_Time(void) {
                     Lcd_Set_Cursor(1, 1);
                     display_Digit(hour);
                 }
+                updateRTC |= (hour_org == hour);
+
                 break;
+
             case 2: //Minutes
                 Lcd_Set_Cursor(2, 16);
                 Lcd_Write_Char('m');
@@ -402,6 +424,8 @@ void edit_Date_Time(void) {
                     Lcd_Set_Cursor(1, 4);
                     display_Digit(min);
                 }
+                updateRTC |= (min_org == min);
+                
                 break;
 
             case 3: //Seconds
@@ -416,6 +440,9 @@ void edit_Date_Time(void) {
                     }
                     Lcd_Set_Cursor(1, 7);
                     display_Digit(sec);
+                    if (sec_org != sec) {
+                        updateRTC = 1;
+                    }
 
                 } else if (!INCR) {
                     __delay_ms(250);
@@ -427,7 +454,12 @@ void edit_Date_Time(void) {
 
                     Lcd_Set_Cursor(1, 7);
                     display_Digit(sec);
+                    if (sec_org != sec) {
+                        updateRTC = 1;
+                    }
                 }
+                updateRTC |= (sec_org == sec);
+                
                 break;
 
             case 6: //Date
@@ -460,6 +492,8 @@ void edit_Date_Time(void) {
                     Lcd_Set_Cursor(2, 6);
                     display_Digit(date);
                 }
+                updateRTC |= (date_org == date);
+                
                 break;
 
             case 5: //Month
@@ -486,6 +520,8 @@ void edit_Date_Time(void) {
                     Lcd_Set_Cursor(2, 9);
                     display_Digit(month);
                 }
+                updateRTC |= (month_org == month);
+                
                 break;
 
             case 4: //Year
@@ -512,10 +548,12 @@ void edit_Date_Time(void) {
                     Lcd_Set_Cursor(2, 14);
                     display_Digit(year);
                 }
+                updateRTC |= (year_org == year);
+                
                 break;
 
                 //TODO Maybe add a case to edit century on display
-                
+
             default:
                 break;
         }
@@ -527,19 +565,23 @@ void edit_Date_Time(void) {
     }
 
     // TODO Edit alarms
-    
+
     /*
      * Set button pressed after Date selection then we set the values in RTC.
      * Unset edit_datetime until next time set button is pressed and clear
      * field text from lower right of display.
      */
     if (edit_datetime > 6) {
-        Set_Time();
-        Set_DayOfWeek(Get_DayOfWeek(year, month, date));
-        Set_Date();
-        edit_datetime = 0;
         Lcd_Set_Cursor(2, 16);
         Lcd_Write_String(" ");
+        edit_datetime = 0;
+        
+        if(updateRTC) {
+            updateRTC = 0;
+            Set_Time();
+            Set_DayOfWeek(Get_DayOfWeek(year, month, date));
+            Set_Date();
+        }
     }
 }
 
-- 
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