From 1fd98882013edcc615616d376ef7834904dcfc90 Mon Sep 17 00:00:00 2001
From: Philipp Klaus <pklaus@platinum.(none)>
Date: Tue, 9 Jul 2013 03:34:25 +0200
Subject: [PATCH] Code cleanup and increased test display update speed to get
 character drops to test with

---
 .../tinyLCD_I2C_Test/tinyLCD_I2C_Test.ino     |  2 +-
 firmware/tinyLCD_I2C/tinyLCD_I2C.ino          | 68 ++++++-------------
 src/tinyLCD_I2C/tinyLCD_I2C.cpp               | 35 +---------
 3 files changed, 25 insertions(+), 80 deletions(-)

diff --git a/examples/tinyLCD_I2C_Test/tinyLCD_I2C_Test.ino b/examples/tinyLCD_I2C_Test/tinyLCD_I2C_Test.ino
index b685b0a..a7354c1 100644
--- a/examples/tinyLCD_I2C_Test/tinyLCD_I2C_Test.ino
+++ b/examples/tinyLCD_I2C_Test/tinyLCD_I2C_Test.ino
@@ -24,5 +24,5 @@ void loop() {
   lcd.setCursor(0,1);
   lcd.print(millis()/1);
   lcd.print(" ms");
-  delay(1000);
+  delay(100);
 }
diff --git a/firmware/tinyLCD_I2C/tinyLCD_I2C.ino b/firmware/tinyLCD_I2C/tinyLCD_I2C.ino
index 52ef9f3..0eea42a 100644
--- a/firmware/tinyLCD_I2C/tinyLCD_I2C.ino
+++ b/firmware/tinyLCD_I2C/tinyLCD_I2C.ino
@@ -25,9 +25,8 @@
 #define LCD_BACKLIGHT 0x81
 #define LCD_NOBACKLIGHT 0x80
 
-// I2C address/buffersize
+// I2C default address
 #define I2C_SLAVE_ADDRESS 0x50
-#define TWI_RX_BUFFER_SIZE ( 32 )
 
 #define CONTRAST_PIN 2
 
@@ -49,11 +48,10 @@ volatile byte reg_position;
 unsigned int buf_ix = 0; 
 // store time when the last char to print was received
 unsigned long lastwrite = 0;
-// char buffer for incoming strings
-char bigbuffer[32];
 // more data expected
 volatile byte data_expected = 0;
 
+
 // initialize the library with the numbers of the interface pins
 // LiquidCrystal(rs, enable, d4, d5, d6, d7);
 // Breadboard:
@@ -68,7 +66,7 @@ void setup() {
     slave_address = I2C_SLAVE_ADDRESS;
   }
   TinyWireS.begin(slave_address);
-  TinyWireS.onReceive(receiveEvent);
+  TinyWireS.onReceive(receive_event);
   //TinyWireS.onRequest(requestEvent);
   analogWrite(CONTRAST_PIN, 10);
   lcd.begin(16,2);
@@ -77,15 +75,12 @@ void setup() {
 }
 
 void loop() {
-  if ( buf_ix > 0 && micros() - lastwrite > CHARBUF_TIMEOUT ) {
-    flush_buffer();
-  }
   TinyWireS_stop_check();
 }
 
 
 // not used yet:
-void requestEvent()
+void request_event()
 {  
     TinyWireS.send(i2c_regs[reg_position]);
     // Increment the reg position on each read, and loop back to zero
@@ -94,40 +89,25 @@ void requestEvent()
     lcd.print("=");
 }
 
-void receiveEvent(uint8_t howMany) {
-  //static int buf_ix = 0;
-  if (howMany < 1)
-  {
-      // Sanity-check
-      return;
-  }
-
-  char cmd = TinyWireS.receive();
-  // wait for a command
-  if ( cmd == 0 ) {
-    while (howMany < 1) {
-      tws_delay(1);    
-    }
-    char rxbuffer = TinyWireS.receive();
-    commandByte(rxbuffer);
-  }
-  /*
-  // direct print
-  else if ( cmd == 1 ) {
-    //lcd.print(rxbuffer);
-    // are we receiving a larger string ? Keep adding to buffer
-    if ( buf_ix == 0 || micros() - lastwrite < CHARBUF_TIMEOUT ) {
-      bigbuffer[buf_ix] = rxbuffer;
-      buf_ix++;
-    }
-  }
-  */
-  else if ( cmd > 1 ) {
-    lcd.print(cmd);
-  }
+void receive_event(uint8_t howMany) {
+	//static int buf_ix = 0;
+	if (howMany < 1) {
+		// Sanity-check
+		return;
+	}
+	while (TinyWireS.available()) {
+		char cmd = TinyWireS.receive();
+		// wait for a command
+		if ( cmd == 0 && howMany > 1 ) {
+			char rxbuffer = TinyWireS.receive();
+			command_byte(rxbuffer, howMany - 2);
+		} else if ( cmd > 1 ) {
+			lcd.print(cmd);
+		}
+	}
 }
 
-void commandByte(char c) {
+void command_byte(char c, byte bytesInBuffer) {
   uint8_t cols, rows, col, row, addr;
   switch (c) {
     case LCD_CLEARDISPLAY:
@@ -217,12 +197,6 @@ void lcd_revision() {
   lcd.print("$Revision: 1.13 $");
 }
 
-// flush receive buffer and output to LCD
-void flush_buffer() {
-  lcd.print(bigbuffer);
-  buf_ix = 0;
-  memset(&bigbuffer[0], 0, sizeof(bigbuffer));
-}
 
 void test_lcd() {
   lcd.print("==T=E=S=T=======");
diff --git a/src/tinyLCD_I2C/tinyLCD_I2C.cpp b/src/tinyLCD_I2C/tinyLCD_I2C.cpp
index c94015f..f9b2584 100644
--- a/src/tinyLCD_I2C/tinyLCD_I2C.cpp
+++ b/src/tinyLCD_I2C/tinyLCD_I2C.cpp
@@ -173,43 +173,14 @@ inline size_t tinyLCD_I2C::write(uint8_t value) {
 
 // write either command or data
 void tinyLCD_I2C::send(uint8_t value, uint8_t mode) {
-	/*
-  uint8_t highnib=value>>4;
-	uint8_t lownib=value & 0x0F;
-	write4bits((highnib)|mode);
-	write4bits((lownib)|mode);
-  */
 	Wire.beginTransmission(_Addr);
-  if ( mode == 0 ) {
-    Wire.write(mode);
-  }
-  // bad delay, need to make the opposite site faster by using a buffer
-  delayMicroseconds(80);  
+	if ( mode == 0 ) {
+		Wire.write(mode);
+	}
 	Wire.write((int)(value));
 	Wire.endTransmission();   
 }
 
-/*
-void tinyLCD_I2C::write4bits(uint8_t value) {
-	expanderWrite(value);
-	pulseEnable(value);
-}
-
-void tinyLCD_I2C::expanderWrite(uint8_t _data){                                        
-	Wire.beginTransmission(_Addr);
-	Wire.write((int)(_data) | _backlightval);
-	Wire.endTransmission();   
-}
-
-void tinyLCD_I2C::pulseEnable(uint8_t _data){
-  expanderWrite(_data | En);	// En high
-	delayMicroseconds(1);		// enable pulse must be >450ns
-	
-	expanderWrite(_data & ~En);	// En low
-	delayMicroseconds(50);		// commands need > 37us to settle
-} 
-*/
-
 
 // Alias functions