Removed old comments, fixed high latency issue

README.md

@@ -35,5 +35,6 @@ By default, uploading this program and then writing to the serial device doesn't
 3. Write stuff to the serial device - now it should work
 
 ### Previously was working
-I basically had to rewrite this from scratch - the Arduino had the program uploaded on it but I lost the code. That version had fast refresh rates but this one takes like 2 seconds to refresh the LCD. I don't have any applications that would break due to this so it isn't important. 
+I basically had to rewrite this from scratch - the Arduino had the program uploaded on it but I lost the code. ~~That version had fast refresh rates but this one takes like 2 seconds to refresh the LCD. I don't have any applications that would break due to this so it isn't important. ~~
+I fixed this issue. Apparently `Serial.readString()` is extremely slow, but `Serial.readStringUntil('\n')` (equivalent in this case) is much faster. Not sure on why but it works. I have effectively instant updates now. 
 

main.cpp

@@ -1,85 +1,36 @@
-/*
-  LiquidCrystal Library - Hello World
-
- Demonstrates the use a 16x2 LCD display.  The LiquidCrystal
- library works with all LCD displays that are compatible with the
- Hitachi HD44780 driver. There are many of them out there, and you
- can usually tell them by the 16-pin interface.
-
- This sketch prints "Hello World!" to the LCD
- and shows the time.
-
-  The circuit:
- * LCD RS pin to digital pin 12
- * LCD Enable pin to digital pin 11
- * LCD D4 pin to digital pin 5
- * LCD D5 pin to digital pin 4
- * LCD D6 pin to digital pin 3
- * LCD D7 pin to digital pin 2
- * LCD R/W pin to ground
- * LCD VSS pin to ground
- * LCD VCC pin to 5V
- * 10K resistor:
- * ends to +5V and ground
- * wiper to LCD VO pin (pin 3)
-
- Library originally added 18 Apr 2008
- by David A. Mellis
- library modified 5 Jul 2009
- by Limor Fried (http://www.ladyada.net)
- example added 9 Jul 2009
- by Tom Igoe
- modified 22 Nov 2010
- by Tom Igoe
- modified 7 Nov 2016
- by Arturo Guadalupi
-
- This example code is in the public domain.
-
- https://docs.arduino.cc/learn/electronics/lcd-displays
-
-*/
-
 // include the library code:
 #include <Arduino.h>
 #include <LiquidCrystal.h>
-//#include <Time.h>
 
 // initialize the library by associating any needed LCD interface pin
 // with the arduino pin number it is connected to
 const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
 LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
+char buffer_line1[16];
+char buffer_line2[16];
+
 
 void setup() {
 	Serial.begin(115200);
 	// set up the LCD's number of columns and rows:
 	lcd.begin(16, 2);
 	lcd.clear();
-	// Print a message to the LCD.
-	//lcd.print("hello, world!");
 }
 
 void loop() {
-	
-	// set the cursor to column 0, line 1
-	// (note: line 1 is the second row, since counting begins with 0):
-	lcd.setCursor(0, 0);
-	// print the number of seconds since reset:
-	//lcd.print(millis() / 1000);
 	while (Serial.available() == 0) {}
-	//lcd.clear();
+	lcd.clear();
-	String s = Serial.readString();
+	lcd.setCursor(0, 0);
-	s.trim();
+	String s1 = Serial.readStringUntil('\n'); // This fixed performance issue
-	int nl_idx = s.indexOf("?", 0);
+	int nl_idx = s1.indexOf("?", 0);
 	if (nl_idx == -1) {
-		lcd.print(s);
+		lcd.print(s1);
 	}
 	else {
-		String l1 = s.substring(0, nl_idx);
+		String s2 = s1.substring(nl_idx+1, s1.length());
-		String l2 = s.substring(nl_idx+1, s.length());
+		s1 = s1.substring(0, nl_idx);
-		lcd.print(l1);
+		lcd.print(s1);
 		lcd.setCursor(0, 1);
-		lcd.print(l2);
+		lcd.print(s2);
-		
 	}
 }