From 3592bd18dd45171387460a8c7ac94508559b9582 Mon Sep 17 00:00:00 2001
From: Florian Pritz <bluewind@xinu.at>
Date: Sat, 13 Apr 2013 16:30:44 +0200
Subject: Make display size configurable and properly buffer input

Signed-off-by: Florian Pritz <bluewind@xinu.at>
---
 src/main.cpp | 47 +++++++++++++++++++++++++++++++++++------------
 1 file changed, 35 insertions(+), 12 deletions(-)

diff --git a/src/main.cpp b/src/main.cpp
index f246e3a..8c67729 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -5,8 +5,18 @@
 void setup();
 void loop();
 
-#define BUFFER_SIZE 64
+// buffer size must be > LCD_CHARS
+#define BUFFER_SIZE 80
+char display_data[BUFFER_SIZE];
 char buf[BUFFER_SIZE];
+int buffered = 0;
+
+#define LCD_ROWS 2
+#define LCD_COLS 16
+#define LCD_CHARS (LCD_COLS * LCD_ROWS)
+#if LCD_CHARS > BUFFER_SIZE
+#error "BUFFER too small"
+#endif
 
 // initialize the library with the numbers of the interface pins
 #ifdef ENERGIA
@@ -28,7 +38,7 @@ Bounce bounce_buttons[NUMBUTTONS];
 
 void setup() {
 	byte i;
-	lcd.begin(16, 2);
+	lcd.begin(LCD_COLS, LCD_ROWS);
 
 // The usb chip hangs if it tries to send data and no-one listens
 // so we give the client time to start up first
@@ -54,7 +64,8 @@ void setup() {
 	}
 
 	Serial.println("ready");
-	lcd.print("Serial ready");
+	memset(display_data, ' ', BUFFER_SIZE);
+	strcpy(display_data, "Waiting for data");
 }
 
 bool button_just_pressed(int i) {
@@ -75,16 +86,28 @@ void loop() {
 		Serial.println("next");
 	}
 
-	// output what we got over serial
-	if (Serial.available() >= 32) {
-		lcd.setCursor(0, 0);
-		Serial.readBytes(buf, 32);
-		for (int i = 0; i < 32; i++) {
-			if (i == 16) {
-				lcd.setCursor(0, 1);
-			}
-			lcd.write(buf[i]);
+	// buffer serial input ourselves
+	if (Serial.available() >= 1) {
+		buffered += Serial.readBytes(buf + buffered, LCD_CHARS - buffered);
+	}
+
+	if (buffered >= LCD_CHARS) {
+		strcpy(display_data, buf);
+		buffered = 0;
+	}
+
+	// update display
+	lcd.setCursor(0, 0);
+	int line = -1;
+	for (int i = 0; i < LCD_CHARS; i++) {
+		if (display_data[i] == '\0') {
+			break;
+		}
+		if (i % LCD_COLS == 0) {
+			line++;
+			lcd.setCursor(0, line);
 		}
+		lcd.write(display_data[i]);
 	}
 }
 
-- 
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