Added battery icon printing

TODO

@@ -1,16 +1 @@
---- main.c ---
+Battery icon - how to calc percentage?
-Battery icon
-Check when to read battery
-
---- UI ---
-123456mm >A
-123456mm >B
-          _
-XXXXXXXX | |
-XXXXXXXX | |
-XXXXXXXX |_|
-
-Battery Image - 24x48 px
-2px White Border
-2px Black Border
-2px horizontal segments per 5%

code/main.c

@@ -40,6 +40,13 @@
 #define OLED_X_SIZE		128
 #define OLED_Y_SIZE		64
 
+#define OLED_BATTERY_ICON_X1		(OLED_X_SIZE - (CHAR_SIZE + 1) * 2 * 2)
+#define OLED_BATTERY_ICON_X2		(OLED_X_SIZE - 1)
+#define OLED_BATTERY_ICON_Y1		2
+#define OLED_BATTERY_ICON_Y2		((OLED_Y_SIZE / 8) - 1)
+#define OLED_BATTERY_ICON_SIZE		2
+#define OLED_BATTERY_ICON_PERCENT	5
+
 // Time(ms) to keep the display on before sleep
 #define DISPLAY_DELAY	3000
 
@@ -262,6 +269,9 @@ void display_send_cmd(uint8_t cmd);
 // OLED send data helper
 void display_send_data(const uint8_t *data, uint16_t buflen);
 
+// OLED print area helper
+void display_set_area(uint8_t start_x, uint8_t end_x, uint8_t start_y, uint8_t end_y);
+
 // OLED init
 void display_init();
 
@@ -609,6 +619,60 @@ void display_send_data(const uint8_t *data, uint16_t buflen)
 	}
 }
 
+void display_set_area(uint8_t start_x, uint8_t end_x, uint8_t start_y, uint8_t end_y)
+{
+	uint8_t cmd_list[6] =
+	{
+		0x21, // Set Column Address
+		0x00, // Start Address
+		0x00, // End Address
+		0x22, // Set Page Address
+		0x00, // Start Page
+		0x00  // End Page
+	};
+	uint8_t i;
+
+	if (start_x >= OLED_X_SIZE)
+	{
+		start_x = OLED_X_SIZE - 1;
+	}
+
+	if (end_x >= OLED_X_SIZE)
+	{
+		end_x = OLED_X_SIZE - 1;
+	}
+
+	if (end_x < start_x)
+	{
+		end_x = start_x;
+	}
+
+	if (start_y >= (OLED_Y_SIZE / 8))
+	{
+		start_y = (OLED_Y_SIZE / 8) - 1;
+	}
+
+	if (end_y >= (OLED_Y_SIZE / 8))
+	{
+		end_y = (OLED_Y_SIZE / 8) - 1;
+	}
+
+	if (end_y < start_y)
+	{
+		end_y = start_y;
+	}
+
+	cmd[1] = start_x;
+	cmd[2] = end_x;
+	cmd[4] = start_y;
+	cmd[5] = end_y;
+
+	for (i = 0; i < sizeof(cmd_list); ++i)
+	{
+		display_send_cmd(cmd_list[i]);
+	}
+}
+
 void display_init()
 {
 	uint16_t i;
@@ -722,15 +786,6 @@ void get_symbol16(uint8_t index, uint8_t *out)
 void print_symbol(uint8_t symbol_idx, uint8_t x, uint8_t y, uint8_t invert)
 {
 	uint8_t unfolded_symbol[CHAR_SIZE * 4];
-	uint8_t cmd_list[6] = 
-	{
-		0x21, // Set Column Address
-		0x00, // Start Address
-		0x00, // End Address
-		0x22, // Set Page Address
-		0x00, // Start Page 0
-		0x00 // End Page
-	};
 	uint8_t i;
 
 	get_symbol16(symbol_idx, unfolded_symbol);
@@ -750,16 +805,7 @@ void print_symbol(uint8_t symbol_idx, uint8_t x, uint8_t y, uint8_t invert)
 		x = OLED_X_SIZE - CHAR_SIZE * 2;
 	}
 
-	cmd_list[1] = x;
+	display_set_area(x, x + CHAR_SIZE * 2 - 1, y * 2, y * 2 + 1);
-	cmd_list[2] = x + CHAR_SIZE * 2 - 1;
-	cmd_list[4] = y * 2;
-	cmd_list[5] = y * 2 + 1;
-
-	for (i = 0; i < sizeof(cmd_list); ++i)
-	{
-		display_send_cmd(cmd_list[i]);
-	}
-
 	display_send_data(unfolded_symbol, sizeof(unfolded_symbol));
 }
 
@@ -894,10 +940,7 @@ void print_clear_menu_area()
 	// End Y - Depends On OLED Size
 	cmd_list[5] = (OLED_Y_SIZE / 8) - 1;
 
-	for (i = 0; i < sizeof(cmd_list); ++i)
+	display_set_area(0, OLED_BATTERY_ICON_X1 - 1, 2, (OLED_Y_SIZE / 8) - 1);
-	{
-		display_send_cmd(cmd_list[i]);
-	}
 
 	for (i = 0; i < sizeof(data); ++i)
 	{
@@ -962,6 +1005,106 @@ void print_option(uint8_t option)
 
 void print_battery_icon()
 {
+	static uint8_t old_percent = 0xFF;
+	uint8_t buf[16];
+	uint8_t i;
+	uint8_t y;
+	uint8_t percent;
+	uint8_t threshold;
+	uint8_t bits;
+	uint8_t mask;
+
+	for (i = 0; i < sizeof(buf), ++i)
+	{
+		buf[i] = 0xFF;
+	}
+
+// Buffer safety
+#if ((OLED_BATTERY_ICON_Y2 - OLED_BATTERY_ICON_Y1 + 1) * OLED_BATTERY_ICON_SIZE > sizeof(buf))
+#error "THIS Y OVERFLOWS"
+#endif
+
+	// Draw left/right borders only once
+	if (0xFF == old_percent)
+	{
+		// Draw left border
+		display_set_area(OLED_BATTERY_ICON_X1, OLED_BATTERY_ICON_X1 + OLED_BATTERY_ICON_SIZE - 1,
+			OLED_BATTERY_ICON_Y1, OLED_BATTERY_ICON_Y2);
+		display_send_data(buf, (OLED_BATTERY_ICON_Y2 - OLED_BATTERY_ICON_Y1 + 1) * OLED_BATTERY_ICON_SIZE);
+
+		// Draw right border
+		display_set_area(OLED_BATTERY_ICON_X2 - 1, OLED_BATTERY_ICON_X2,
+			OLED_BATTERY_ICON_Y1, OLED_BATTERY_ICON_Y2);
+		display_send_data(buf, (OLED_BATTERY_ICON_Y2 - OLED_BATTERY_ICON_Y1 + 1) * OLED_BATTERY_ICON_SIZE);
+	}
+
+	// TODO: Calc battery percent
+	percent = 50;
+
+	// Do not draw if not needed
+	if ((old_percent / OLED_BATTERY_ICON_PERCENT) == (percent / OLED_BATTERY_ICON_PERCENT))
+	{
+		old_percent = percent;
+		return;
+	}
+
+	// Set bitmask
+	bits = 0x00;
+	for (i = 0; i < OLED_BATTERY_ICON_SIZE; ++i)
+	{
+		bits <<= 1;
+		bits += 1;
+	}
+
+	// Threshold is artificially bigger to not draw over border
+	// On lower border it underflows
+	threshold = 100 - ((OLED_BATTERY_ICON_PERCENT + 1) / 2) + OLED_BATTERY_ICON_PERCENT * 2;
+
+	for (y = OLED_BATTERY_ICON_Y1, y <= OLED_BATTERY_ICON_Y2; ++y)
+	{
+		mask = 0x00;
+
+		for (i = 0; i < 8 / OLED_BATTERY_ICON_SIZE; ++i)
+		{
+			mask <<= OLED_BATTERY_ICON_SIZE;
+			if (percent > threshold)
+			{
+				mask |= bits;
+			}
+
+			threshold -= OLED_BATTERY_ICON_PERCENT;
+		}
+
+		// Add top border
+		if (0 == y)
+		{
+			mask |= (bits << (8 - OLED_BATTERY_ICON_SIZE));
+		}
+
+		// Add bottom border
+		if (OLED_BATTERY_ICON_Y2 == y)
+		{
+			mask |= bits;
+		}
+
+		// Fill buffer
+		for (i = 0; i < sizeof(buf); ++i)
+		{
+			buf[i] = mask;
+		}
+
+		// Diplay percent
+		display_set_area(OLED_BATTERY_ICON_X1 + OLED_BATTERY_ICON_SIZE * 2,
+			OLED_BATTERY_ICON_X2 - OLED_BATTERY_ICON_SIZE * 2,
+			y, y);
+		display_send_data(buf, OLED_BATTERY_ICON_X2 - OLED_BATTERY_ICON_X1 -
+			OLED_BATTERY_ICON_SIZE * 4 + 1);
+	}
+
+// Buffer safety
+#if ((OLED_BATTERY_ICON_X2 - OLED_BATTERY_ICON_X1 - OLED_BATTERY_ICON_SIZE * 4 + 1) > sizeof(buf))
+#error "THIS X OVERFLOWS"
+#endif
 
 }