diff 1wire-config.h @ 32:b0cb873c0206

Isolate the bus frobbing parts and the delays into a separate header. This means the user only has to edit a single file to suit their situation and allows the code to work with active drive systems as well as passive pullups (ie 1 vs 2 IO pins)
author darius
date Sun, 23 Apr 2006 22:57:16 +0930
parents
children 0aa6bf4b98ae
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/1wire-config.h	Sun Apr 23 22:57:16 2006 +0930
@@ -0,0 +1,72 @@
+/*
+ * 1 wire header
+ *
+ * This is the user servicable stuff - how to do delays and how to
+ * frob the IO pins.
+ *
+ * $Id$
+ *
+ * Copyright (c) 2004
+ *      Daniel O'Connor <darius@dons.net.au>.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Alter these for your configuration
+ */
+
+/* Set DDR on the right pins */
+#define OWBUSINIT()		do {			\
+	                            DDRD |= _BV(4);	\
+				    DDRD &= ~_BV(3);	\
+                                } while (0)
+
+/* Read the 1-wire bus, non-inverting logic */
+#define OWREADBUS()		(PIND & _BV(3) ? 1 : 0)
+
+/* Set the 1-wire bus to 0
+ * Turns a transistor on to pull it low
+ */
+#define OWSETBUSLOW()		PORTD |= _BV(4)
+
+/* Set the 1-wire bus to 1
+ * Turn the transistor off to let the pullup do its job
+ */
+#define OWSETBUSHIGH()		PORTD &= ~_BV(4)
+
+/* _delay_us can only do a delay of 768/clock_freq */
+#if F_CPU > 16000000
+#error F_CPU > 16MHz, delays need adjusting
+#endif
+
+#define OWDELAY_A _delay_us(6)						/* 6 usec */
+#define OWDELAY_B do { _delay_us(48); _delay_us(16); } while (0)	/* 64 usec */
+#define OWDELAY_C do { _delay_us(48); _delay_us(12); } while (0)	/* 60 usec */
+#define OWDELAY_D _delay_us(10)						/* 10 usec */
+#define OWDELAY_E _delay_us(9)						/* 9 usec */
+#define OWDELAY_F do { _delay_us(55); } while (0)			/* 55 usec */
+#define OWDELAY_G							/* 0 usec */
+#define OWDELAY_H do { _delay_us(48); _delay_us(48);  _delay_us(48); 	\
+	_delay_us(48);	_delay_us(48);  _delay_us(48);  _delay_us(48);  \
+	_delay_us(48);_delay_us(48);  _delay_us(48); } while (0)	/* 480 usec */
+#define OWDELAY_I do { _delay_us(48); _delay_us(22); } while (0)	/* 70 usec */