Mercurial > ~darius > hgwebdir.cgi > avr
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 */