Jan Achterhold / OneWire

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OneWire.cpp@0:79a1b7700cf2, 2010-11-22 (annotated)

Committer:
jan_waf
Date:
Mon Nov 22 21:51:22 2010 +0000
Revision:
0:79a1b7700cf2
Version 0.9.1

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jan_waf 0:79a1b7700cf2 1 /* 1-Wire-Master Library
jan_waf 0:79a1b7700cf2 2 * Copyright (c) 2010 Jan Achterhold
jan_waf 0:79a1b7700cf2 3 *
jan_waf 0:79a1b7700cf2 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
jan_waf 0:79a1b7700cf2 5 * of this software and associated documentation files (the "Software"), to deal
jan_waf 0:79a1b7700cf2 6 * in the Software without restriction, including without limitation the rights
jan_waf 0:79a1b7700cf2 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
jan_waf 0:79a1b7700cf2 8 * copies of the Software, and to permit persons to whom the Software is
jan_waf 0:79a1b7700cf2 9 * furnished to do so, subject to the following conditions:
jan_waf 0:79a1b7700cf2 10 *
jan_waf 0:79a1b7700cf2 11 * The above copyright notice and this permission notice shall be included in
jan_waf 0:79a1b7700cf2 12 * all copies or substantial portions of the Software.
jan_waf 0:79a1b7700cf2 13 *
jan_waf 0:79a1b7700cf2 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
jan_waf 0:79a1b7700cf2 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
jan_waf 0:79a1b7700cf2 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
jan_waf 0:79a1b7700cf2 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
jan_waf 0:79a1b7700cf2 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
jan_waf 0:79a1b7700cf2 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
jan_waf 0:79a1b7700cf2 20 * THE SOFTWARE.
jan_waf 0:79a1b7700cf2 21 */
jan_waf 0:79a1b7700cf2 22
jan_waf 0:79a1b7700cf2 23 /* 1-Wire-Master, currently without multiple slave support */
jan_waf 0:79a1b7700cf2 24
jan_waf 0:79a1b7700cf2 25 #include "mbed.h"
jan_waf 0:79a1b7700cf2 26 #include "OneWire.h"
jan_waf 0:79a1b7700cf2 27
jan_waf 0:79a1b7700cf2 28 OneWire::OneWire(PinName _owpin) : owpin(_owpin) {
jan_waf 0:79a1b7700cf2 29 owpin.mode(PullDown);
jan_waf 0:79a1b7700cf2 30 }
jan_waf 0:79a1b7700cf2 31
jan_waf 0:79a1b7700cf2 32 OneWire::~OneWire() {
jan_waf 0:79a1b7700cf2 33 };
jan_waf 0:79a1b7700cf2 34
jan_waf 0:79a1b7700cf2 35 // Reads 1-Wire ROM-Code
jan_waf 0:79a1b7700cf2 36 void OneWire::getRomCode(char *rc) {
jan_waf 0:79a1b7700cf2 37 this->busInit();
jan_waf 0:79a1b7700cf2 38 // Sends ROM-Code sending command to the bus
jan_waf 0:79a1b7700cf2 39 this->writeByte(0x33);
jan_waf 0:79a1b7700cf2 40 // Reads 8-byte ROM-Code
jan_waf 0:79a1b7700cf2 41 for (int i=0; i<=7; i++) {
jan_waf 0:79a1b7700cf2 42 rc[i] = this->readByte();
jan_waf 0:79a1b7700cf2 43 }
jan_waf 0:79a1b7700cf2 44 }
jan_waf 0:79a1b7700cf2 45
jan_waf 0:79a1b7700cf2 46 // Commands device to do sth.
jan_waf 0:79a1b7700cf2 47 void OneWire::cmdDevice(char *rc, char cmd) {
jan_waf 0:79a1b7700cf2 48 // Reset
jan_waf 0:79a1b7700cf2 49 this->busInit();
jan_waf 0:79a1b7700cf2 50 // Matches ROM
jan_waf 0:79a1b7700cf2 51 this->writeByte(0x55);
jan_waf 0:79a1b7700cf2 52 for (int i=0; i<=7; i++) {
jan_waf 0:79a1b7700cf2 53 this->writeByte(rc[i]);
jan_waf 0:79a1b7700cf2 54 }
jan_waf 0:79a1b7700cf2 55 // Writes command
jan_waf 0:79a1b7700cf2 56 this->writeByte(cmd);
jan_waf 0:79a1b7700cf2 57 }
jan_waf 0:79a1b7700cf2 58
jan_waf 0:79a1b7700cf2 59 // Gets data from the bus
jan_waf 0:79a1b7700cf2 60 void OneWire::getData(char *data, int bytes) {
jan_waf 0:79a1b7700cf2 61 for (int i=0;i<=bytes-1;i++) {
jan_waf 0:79a1b7700cf2 62 data[i] = this->readByte();
jan_waf 0:79a1b7700cf2 63 }
jan_waf 0:79a1b7700cf2 64 }
jan_waf 0:79a1b7700cf2 65
jan_waf 0:79a1b7700cf2 66 // Writes a bit to the bus
jan_waf 0:79a1b7700cf2 67 void OneWire::writeBit(int bit) {
jan_waf 0:79a1b7700cf2 68 this->owpin.output();
jan_waf 0:79a1b7700cf2 69 this->owpin = 0;
jan_waf 0:79a1b7700cf2 70 wait_us(5);
jan_waf 0:79a1b7700cf2 71 this->owpin = bit;
jan_waf 0:79a1b7700cf2 72 wait_us(60);
jan_waf 0:79a1b7700cf2 73 this->owpin = 1;
jan_waf 0:79a1b7700cf2 74 }
jan_waf 0:79a1b7700cf2 75
jan_waf 0:79a1b7700cf2 76 // Reads a bit from the bus
jan_waf 0:79a1b7700cf2 77 int OneWire::readBit() {
jan_waf 0:79a1b7700cf2 78 int pin;
jan_waf 0:79a1b7700cf2 79 this->owpin.output();
jan_waf 0:79a1b7700cf2 80 this->owpin = 0;
jan_waf 0:79a1b7700cf2 81 wait_us(5);
jan_waf 0:79a1b7700cf2 82 this->owpin = 1;
jan_waf 0:79a1b7700cf2 83 wait_us(3);
jan_waf 0:79a1b7700cf2 84 this->owpin.input();
jan_waf 0:79a1b7700cf2 85 pin = this->owpin;
jan_waf 0:79a1b7700cf2 86 this->owpin.output();
jan_waf 0:79a1b7700cf2 87 wait_us(120);
jan_waf 0:79a1b7700cf2 88 return pin;
jan_waf 0:79a1b7700cf2 89 }
jan_waf 0:79a1b7700cf2 90
jan_waf 0:79a1b7700cf2 91 // Writes a byte to the bus
jan_waf 0:79a1b7700cf2 92 void OneWire::writeByte(unsigned char by) {
jan_waf 0:79a1b7700cf2 93 int b;
jan_waf 0:79a1b7700cf2 94 int i;
jan_waf 0:79a1b7700cf2 95 for (i=0; i<=7; i++) {
jan_waf 0:79a1b7700cf2 96 b = by & 0x01;
jan_waf 0:79a1b7700cf2 97 this->writeBit(b);
jan_waf 0:79a1b7700cf2 98 by = by >> 1;
jan_waf 0:79a1b7700cf2 99 }
jan_waf 0:79a1b7700cf2 100 }
jan_waf 0:79a1b7700cf2 101
jan_waf 0:79a1b7700cf2 102 // Reads Byte from the bus
jan_waf 0:79a1b7700cf2 103 unsigned char OneWire::readByte(void) {
jan_waf 0:79a1b7700cf2 104 unsigned char i;
jan_waf 0:79a1b7700cf2 105 unsigned char wert = 0;
jan_waf 0:79a1b7700cf2 106 for (i=0; i<8; i++) {
jan_waf 0:79a1b7700cf2 107 if (this->readBit()) wert |=0x01 << i;
jan_waf 0:79a1b7700cf2 108 }
jan_waf 0:79a1b7700cf2 109 return(wert);
jan_waf 0:79a1b7700cf2 110 }
jan_waf 0:79a1b7700cf2 111
jan_waf 0:79a1b7700cf2 112
jan_waf 0:79a1b7700cf2 113 // Initializes bus
jan_waf 0:79a1b7700cf2 114 int OneWire::busInit() {
jan_waf 0:79a1b7700cf2 115 int r;
jan_waf 0:79a1b7700cf2 116 this->owpin.output();
jan_waf 0:79a1b7700cf2 117 this->owpin = 0;
jan_waf 0:79a1b7700cf2 118 wait_us(540);
jan_waf 0:79a1b7700cf2 119 this->owpin = 1;
jan_waf 0:79a1b7700cf2 120 this->owpin.input();
jan_waf 0:79a1b7700cf2 121 wait_us(65);
jan_waf 0:79a1b7700cf2 122 r = this->owpin;
jan_waf 0:79a1b7700cf2 123 this->owpin.output();
jan_waf 0:79a1b7700cf2 124 wait_us(540);
jan_waf 0:79a1b7700cf2 125 return r;
jan_waf 0:79a1b7700cf2 126 }