From 2bbbeec87352770305200acf90b4b144494f0338 Mon Sep 17 00:00:00 2001
From: DWW <DWW@Gaming>
Date: Wed, 30 Jun 2021 02:04:22 +0300
Subject: [PATCH] Fixed EEPROM write and state swtich when filament runs out.
 Fixed EEPROM detection

---
 code/main.c | 39 ++++++++++++++++++++++++++++++++-------
 1 file changed, 32 insertions(+), 7 deletions(-)

diff --git a/code/main.c b/code/main.c
index 6b4cc91..64d7416 100644
--- a/code/main.c
+++ b/code/main.c
@@ -315,11 +315,20 @@ int main()
 
 				if (count_value_fine < 0)
 				{
+					// Write the zero to EEPROM
+					++eeprom_idx;
+					eeprom_idx %= EEPROM_SIZE;
+					write_eeprom_val(eeprom_idx, 0, move_dir);
+
 					count_value_fine = 0;
-					state = STATE_SETTING;
 					display_enable(1);
-					needs_update = 1;
+
+					// Switch State
 					sleep_when_ms = 0;
+					long_press_when_ms = 0;
+					highlight = 6;
+					needs_update = 1;
+					state = STATE_SETTING;
 				}
 
 				// Update EEPROM When Meter Value Changes
@@ -339,6 +348,7 @@ int main()
 
 			if ((0 != long_press_when_ms) && (long_press_when_ms < ms))
 			{
+				// Switch State
 				sleep_when_ms = 0;
 				long_press_when_ms = 0;
 				highlight = 6;
@@ -428,15 +438,15 @@ int main()
 					{
 						dir_highlight = 1;
 					}
-					needs_update = 1;
 				}
 				else if (0 != dir_highlight)
 				{
+					// Switch state
+					sleep_when_ms = ms + DISPLAY_DELAY;
 					dir_highlight = 0;
 					state = STATE_COUNTING;
-					sleep_when_ms = ms + DISPLAY_DELAY;
-					needs_update = 1;
 
+					// Write starting value to EEPROM
 					++eeprom_idx;
 					eeprom_idx %= EEPROM_SIZE;
 					write_eeprom_val(eeprom_idx, count_value, move_dir);
@@ -449,6 +459,7 @@ int main()
 			// STATE_SETTING
 			break;
 		}
+
 		if (needs_update)
 		{
 			update_display(count_value, highlight, move_dir, dir_highlight);
@@ -821,10 +832,10 @@ uint16_t measure_voltage()
 
 uint16_t find_eeprom_idx()
 {
-	// TODO: double check everything
 	uint16_t idx = 0;
 	uint8_t found = 0;
 
+	// FF is the erased byte value and is used as prefix
 	for (idx = 0; idx < EEPROM_SIZE; ++idx)
 	{
 		if (0xFF != eeprom_read_byte((uint8_t *) idx))
@@ -839,9 +850,22 @@ uint16_t find_eeprom_idx()
 		return EEPROM_SIZE;
 	}
 
+	// FF XX ...
+	if (1 == idx)
+	{
+		// Check Last byte for value
+		// FF XX ... FF ??
+		if (0xFF != eeprom_read_byte((uint8_t *) EEPROM_SIZE - 1))
+		{
+			idx = EEPROM_SIZE - 1;
+		}
+	}
+
+	// XX ...
 	if (0 == idx)
 	{
-		for (idx = EEPROM_SIZE - 3; idx < EEPROM_SIZE; ++idx)
+		// XX ... FF ?? ??
+		for (idx = EEPROM_SIZE - 2; idx < EEPROM_SIZE; ++idx)
 		{
 			if (0xFF != eeprom_read_byte((uint8_t *) idx))
 			{
@@ -850,6 +874,7 @@ uint16_t find_eeprom_idx()
 		}
 	}
 
+	// idx here is the byte that's not the FF prefix so reverse it by 1
 	idx += EEPROM_SIZE;
 	--idx;
 	idx %= EEPROM_SIZE;