From 91eea0ef0a3cb6d7fcee4e707db82fc19ee395ce Mon Sep 17 00:00:00 2001
From: Raymond Lutz <lutzray@mac.com>
Date: Fri, 15 Sep 2023 21:44:05 -0400
Subject: [PATCH] year zero = 2021

---
 tictaccode_QTPY.ino | 5 +++--
 tictaccode_XIAO.ino | 5 +++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/tictaccode_QTPY.ino b/tictaccode_QTPY.ino
index 622e553..ff2c2a7 100644
--- a/tictaccode_QTPY.ino
+++ b/tictaccode_QTPY.ino
@@ -61,6 +61,7 @@
 #define gps Serial1
 #define console Serial
 #define VERSIONNUM 0  // two bits max
+#define YEAR_ZERO 2021 // for encoding year with offset
 #define DAC_AMPLITUDE 511
 #define DAC_MID_VALUE 511        // (2**10 - 1) / 2
 #define LED_FLASH_DURATION 0.02  // sec
@@ -73,7 +74,7 @@
   1 bit for clock source: bit=1 for GPS; bit=0 for RTC +
   6 bits for secs + 6 bits for min +
   5 bits for hr + 5 bits for day + 4 bit for month +
-  5 bits for year offset (since 2021) = 35
+  5 bits for year offset (since YEAR_ZERO) = 35
 */
 
 
@@ -235,7 +236,7 @@ void punchGPSintoWord() {
   copyBits2timecodeWord(HH, 16, 5);
   copyBits2timecodeWord(DD, 21, 5);
   copyBits2timecodeWord(MT, 26, 4);
-  copyBits2timecodeWord(YY - 2021, 30, 5);
+  copyBits2timecodeWord(YY - YEAR_ZERO, 30, 5);
   for (int i = 0; i <= N_SYMBOLS; i++) {
     if (i == 3 || i == 1 || i == 4 || i == 10 || i == 16 || i == 21 || i == 26 || i == 30)
       console.print(" ");
diff --git a/tictaccode_XIAO.ino b/tictaccode_XIAO.ino
index 4744784..700237e 100644
--- a/tictaccode_XIAO.ino
+++ b/tictaccode_XIAO.ino
@@ -55,6 +55,7 @@ https://www.seeedstudio.com/Seeeduino-XIAO-Arduino-Microcontroller-SAMD21-Cortex
 #define gps Serial1
 #define console Serial
 #define VERSIONNUM 0  // two bits, so 3 max
+#define YEAR_ZERO 2021 // for encoding year with offset
 #define DAC_AMPLITUDE 511
 #define DAC_MID_VALUE 511        // (2**10 - 1) / 2
 #define LED_FLASH_DURATION 0.02  // sec
@@ -67,7 +68,7 @@ https://www.seeedstudio.com/Seeeduino-XIAO-Arduino-Microcontroller-SAMD21-Cortex
   1 bit for clock source: bit=1 for GPS; bit=0 for RTC +
   6 bits for secs + 6 bits for min +
   5 bits for hr + 5 bits for day + 4 bit for month +
-  5 bits for year offset (since 2021) = 35
+  5 bits for year offset (since YEAR_ZERO) = 35
 */
 
 
@@ -226,7 +227,7 @@ void punchGPSintoWord() {
   copyBits2timecodeWord(HH, 16, 5);
   copyBits2timecodeWord(DD, 21, 5);
   copyBits2timecodeWord(MT, 26, 4);
-  copyBits2timecodeWord(YY - 2023, 30, 5);
+  copyBits2timecodeWord(YY - YEAR_ZERO, 30, 5);
   if (PRINT_OUTPUT) {
     for (int i = 0; i <= N_SYMBOLS; i++) {
       if (i == 3 || i == 1 || i == 4 || i == 10 || i == 16 || i == 21 || i == 26 || i == 30)
-- 
2.45.2