From 6623d45af9adf3d1e401c269b49ac81ecd241490 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Gu=C3=B0ni=20M=C3=A1r=20Gilbert?= <gudnimar@noxmedical.com>
Date: Tue, 25 Jul 2023 11:04:12 +0000
Subject: [PATCH] optimisation: Tighter LCD timing

Author: leptun

Change in memory:
Flash: -14 bytes
SRAM: 0 bytes
---
 Firmware/lcd.cpp | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/Firmware/lcd.cpp b/Firmware/lcd.cpp
index 39d84c4bf..5715ca97d 100644
--- a/Firmware/lcd.cpp
+++ b/Firmware/lcd.cpp
@@ -129,18 +129,17 @@ static void lcd_send(uint8_t data, uint8_t flags, uint16_t duration = LCD_DEFAUL
 	_delay_us(5);
 	lcd_writebits(data);
 #ifndef LCD_8BIT
-	if (!(flags & LCD_HALF_FLAG))
-	{
-		_delay_us(LCD_DEFAULT_DELAY);
-		lcd_writebits(data<<4);
+	if (!(flags & LCD_HALF_FLAG)) {
+		// _delay_us(LCD_DEFAULT_DELAY); // should not be needed when sending a two nibble instruction.
+		lcd_writebits((data << 4) | (data >> 4)); //force efficient swap opcode even though the lower nibble is ignored in this case
 	}
 #endif
 	delayMicroseconds(duration);
 }
 
-static void lcd_command(uint8_t value, uint16_t delayExtra = 0)
+static void lcd_command(uint8_t value, uint16_t duration = LCD_DEFAULT_DELAY)
 {
-	lcd_send(value, LOW, LCD_DEFAULT_DELAY + delayExtra);
+	lcd_send(value, LOW, duration);
 }
 
 static void lcd_write(uint8_t value)