From 8111ed7c07a31dd99a323a0a29f9e99dd54c6d80 Mon Sep 17 00:00:00 2001
From: Yuval Adam <yuv.adm@gmail.com>
Date: Wed, 15 May 2013 22:34:48 +0300
Subject: Lots of project tests

---
 demopal/lib/pollserial/pollserial.cpp | 139 ++++++++++++++++++++++++++++++++++
 1 file changed, 139 insertions(+)
 create mode 100755 demopal/lib/pollserial/pollserial.cpp

(limited to 'demopal/lib/pollserial/pollserial.cpp')

diff --git a/demopal/lib/pollserial/pollserial.cpp b/demopal/lib/pollserial/pollserial.cpp
new file mode 100755
index 0000000..a417098
--- /dev/null
+++ b/demopal/lib/pollserial/pollserial.cpp
@@ -0,0 +1,139 @@
+/*
+  pollserial.cpp Heavily modified version of:
+
+  HardwareSerial.cpp - Hardware serial library for Wiring
+  Copyright (c) 2006 Nicholas Zambetti.  All right reserved.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+  
+  Modified 23 November 2006 by David A. Mellis
+  
+  Modified July 2010 by Myles D. Metzler
+*/
+
+#include <avr/io.h>
+#include <stdlib.h>
+#include "pollserial.h"
+
+#define BUFFER_SIZE 64
+
+rbuffer rxbuffer = {0,0,0};
+
+void USART_recieve() {
+#if defined ( UDR0 )
+	if( UCSR0A & _BV(RXC0)) {
+		uint8_t i = (rxbuffer.head + 1) & (BUFFER_SIZE - 1);
+		if ( i != rxbuffer.tail) {
+			rxbuffer.buffer[rxbuffer.head] = UDR0;
+			rxbuffer.head = i;
+		}
+	}
+#else
+	if( UCSRA & _BV(RXC)) {
+		uint8_t i = (rxbuffer.head + 1) & (BUFFER_SIZE - 1);
+		if ( i != rxbuffer.tail) {
+			rxbuffer.buffer[rxbuffer.head] = UDR;
+			rxbuffer.head = i;
+		}
+	}
+#endif
+}
+
+pt2Funct pollserial::begin(long baud) {
+	uint16_t baud_setting;
+	bool use_u2x;
+	
+	rxbuffer.buffer = (unsigned char*)malloc(BUFFER_SIZE*sizeof(unsigned char));
+
+	// U2X mode is needed for baud rates higher than (CPU Hz / 16)
+	if (baud > F_CPU / 16) {
+		use_u2x = true;
+	}
+	else {
+		// figure out if U2X mode would allow for a better connection
+    
+		// calculate the percent difference between the baud-rate specified and
+		// the real baud rate for both U2X and non-U2X mode (0-255 error percent)
+		uint8_t nonu2x_baud_error = abs((int)(255-((F_CPU/(16*(((F_CPU/8/baud-1)/2)+1))*255)/baud)));
+		uint8_t u2x_baud_error = abs((int)(255-((F_CPU/(8*(((F_CPU/4/baud-1)/2)+1))*255)/baud)));
+    
+		// prefer non-U2X mode because it handles clock skew better
+		use_u2x = (nonu2x_baud_error > u2x_baud_error);
+	}
+	if (use_u2x) {
+#if defined ( UDR0 )
+		UCSR0A = _BV(U2X0);
+#else
+		UCSRA = _BV(U2X);
+#endif
+		baud_setting = (F_CPU / 4 / baud - 1) / 2;
+	}
+	else {
+#if defined ( UDR0 )
+		UCSR0A = 0;
+#else
+		UCSRA = 0;
+#endif
+		baud_setting = (F_CPU / 8 / baud - 1) / 2;
+	}
+
+	// assign the baud_setting, a.k.a. (USART Baud Rate Register)
+#if defined ( UDR0 )
+	UBRR0 = baud_setting;
+	UCSR0B = _BV(RXEN0) | _BV(TXEN0);
+#else
+	UBRR = baud_setting;
+	UCSRB = _BV(RXEN) | _BV(TXEN);
+#endif
+
+	return &USART_recieve;
+}
+
+void pollserial::end() {
+	UCSR0B &= ~(_BV(RXEN0) | _BV(TXEN0));
+	free(rxbuffer.buffer);
+}
+
+uint8_t pollserial::available() {
+	return (BUFFER_SIZE + rxbuffer.head - rxbuffer.tail) & (BUFFER_SIZE-1);
+}
+
+int pollserial::read() {
+	if (rxbuffer.head == rxbuffer.tail)
+		return -1;
+	else {
+		uint8_t c = rxbuffer.buffer[rxbuffer.tail];
+		//tail = (tail + 1) & 63;
+		if (rxbuffer.tail == BUFFER_SIZE)
+			rxbuffer.tail = 0;
+		else
+			rxbuffer.tail++;
+		return c;
+	}
+}
+
+void pollserial::flush() {
+	rxbuffer.head = rxbuffer.tail;
+}
+
+size_t pollserial::write(uint8_t c) {
+#if defined ( UDR0 )
+	while (!((UCSR0A) & _BV(UDRE0)));
+	UDR0 = c;
+#else
+	while (!((UCSRA) & _BV(UDRE)));
+	UDR = c;
+#endif
+}
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