Benoit Agache / DS1820

c

Dependencies:   LinkedList

DS1820.h@7:58b61681818f, 2014-04-08 (annotated)

Committer:
Sissors
Date:
Tue Apr 08 09:59:18 2014 +0000
Revision:
7:58b61681818f
Parent:
6:abfdd851218a
Child:
11:1a3c3002b50c
Added define for invalid conversion

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Michael_ 2:ee820a991b95 1 /* mbed DS1820 Library, for the Dallas (Maxim) 1-Wire Digital Thermometer
Michael_ 2:ee820a991b95 2 * Copyright (c) 2010, Michael Hagberg Michael@RedBoxCode.com
Michael_ 2:ee820a991b95 3 *
Michael_ 2:ee820a991b95 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
Michael_ 2:ee820a991b95 5 * of this software and associated documentation files (the "Software"), to deal
Michael_ 2:ee820a991b95 6 * in the Software without restriction, including without limitation the rights
Michael_ 2:ee820a991b95 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
Michael_ 2:ee820a991b95 8 * copies of the Software, and to permit persons to whom the Software is
Michael_ 2:ee820a991b95 9 * furnished to do so, subject to the following conditions:
Michael_ 2:ee820a991b95 10 *
Michael_ 2:ee820a991b95 11 * The above copyright notice and this permission notice shall be included in
Michael_ 2:ee820a991b95 12 * all copies or substantial portions of the Software.
Michael_ 2:ee820a991b95 13 *
Michael_ 2:ee820a991b95 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
Michael_ 2:ee820a991b95 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
Michael_ 2:ee820a991b95 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
Michael_ 2:ee820a991b95 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
Michael_ 2:ee820a991b95 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
Michael_ 2:ee820a991b95 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
Michael_ 2:ee820a991b95 20 * THE SOFTWARE.
Michael_ 2:ee820a991b95 21 */
Michael_ 2:ee820a991b95 22
Michael_ 2:ee820a991b95 23 #ifndef MBED_DS1820_H
Michael_ 2:ee820a991b95 24 #define MBED_DS1820_H
Michael_ 2:ee820a991b95 25
Michael_ 2:ee820a991b95 26 #include "mbed.h"
Sissors 5:2cd4928e8147 27 #include "LinkedList.h"
Michael_ 2:ee820a991b95 28
Sissors 5:2cd4928e8147 29 #define FAMILY_CODE _ROM[0]
Sissors 5:2cd4928e8147 30 #define FAMILY_CODE_DS1820 0x10
Sissors 5:2cd4928e8147 31 #define FAMILY_CODE_DS18B20 0x28
Sissors 5:2cd4928e8147 32 #define FAMILY_CODE_DS1822 0x22
Michael_ 2:ee820a991b95 33
Michael_ 2:ee820a991b95 34 /** DS1820 Dallas 1-Wire Temperature Probe
Michael_ 2:ee820a991b95 35 *
Michael_ 2:ee820a991b95 36 * Example:
Michael_ 2:ee820a991b95 37 * @code
Michael_ 2:ee820a991b95 38 * #include "mbed.h"
Michael_ 2:ee820a991b95 39 * #include "DS1820.h"
Michael_ 2:ee820a991b95 40 *
Sissors 5:2cd4928e8147 41 * DS1820 probe(DATA_PIN);
Sissors 5:2cd4928e8147 42 *
Michael_ 2:ee820a991b95 43 * int main() {
Sissors 5:2cd4928e8147 44 * while(1) {
Sissors 5:2cd4928e8147 45 * probe.convertTemperature(true, DS1820::all_devices); //Start temperature conversion, wait until ready
Sissors 5:2cd4928e8147 46 * printf("It is %3.1foC\r\n", probe.temperature());
Sissors 5:2cd4928e8147 47 * wait(1);
Michael_ 2:ee820a991b95 48 * }
Michael_ 2:ee820a991b95 49 * }
Michael_ 2:ee820a991b95 50 * @endcode
Michael_ 2:ee820a991b95 51 */
Michael_ 2:ee820a991b95 52 class DS1820 {
Michael_ 2:ee820a991b95 53 public:
Michael_ 2:ee820a991b95 54 enum devices{
Michael_ 2:ee820a991b95 55 this_device, // command applies to only this device
Michael_ 2:ee820a991b95 56 all_devices }; // command applies to all devices
Sissors 7:58b61681818f 57
Sissors 7:58b61681818f 58 enum {
Sissors 7:58b61681818f 59 invalid_conversion = -1000
Sissors 7:58b61681818f 60 };
Michael_ 2:ee820a991b95 61
Michael_ 2:ee820a991b95 62 /** Create a probe object connected to the specified pins
Sissors 5:2cd4928e8147 63 *
Sissors 5:2cd4928e8147 64 * The probe might either by regular powered or parasite powered. If it is parasite
Sissors 5:2cd4928e8147 65 * powered and power_pin is set, that pin will be used to switch an external mosfet connecting
Sissors 5:2cd4928e8147 66 * data to Vdd. If it is parasite powered and the pin is not set, the regular data pin
Sissors 5:2cd4928e8147 67 * is used to supply extra power when required. This will be sufficient as long as the
Sissors 5:2cd4928e8147 68 * number of probes is limitted.
Michael_ 2:ee820a991b95 69 *
Michael_ 2:ee820a991b95 70 * @param data_pin DigitalInOut pin for the data bus
Sissors 5:2cd4928e8147 71 * @param power_pin DigitalOut (optional) pin to control the power MOSFET
Sissors 5:2cd4928e8147 72 * @param power_polarity bool (optional) which sets active state (0 for active low (default), 1 for active high)
Michael_ 2:ee820a991b95 73 */
Sissors 5:2cd4928e8147 74 DS1820(PinName data_pin, PinName power_pin = NC, bool power_polarity = 0); // Constructor with parasite power pin
Sissors 5:2cd4928e8147 75 ~DS1820();
Michael_ 2:ee820a991b95 76
Sissors 5:2cd4928e8147 77 /** Function to see if there are DS1820 devices left on a pin which do not have a corresponding DS1820 object
Sissors 5:2cd4928e8147 78 *
Sissors 5:2cd4928e8147 79 * @return - true if there are one or more unassigned devices, otherwise false
Michael_ 2:ee820a991b95 80 */
Sissors 5:2cd4928e8147 81 static bool unassignedProbe(PinName pin);
Michael_ 2:ee820a991b95 82
Michael_ 2:ee820a991b95 83 /** This routine will initiate the temperature conversion within
Sissors 5:2cd4928e8147 84 * one or all DS1820 probes.
Michael_ 2:ee820a991b95 85 *
pairmand 3:8f2b7f4940b5 86 * @param wait if true or parisitic power is used, waits up to 750 ms for
pairmand 3:8f2b7f4940b5 87 * conversion otherwise returns immediatly.
pairmand 3:8f2b7f4940b5 88 * @param device allows the function to apply to a specific device or
Michael_ 2:ee820a991b95 89 * to all devices on the 1-Wire bus.
pairmand 3:8f2b7f4940b5 90 * @returns milliseconds untill conversion will complete.
Michael_ 2:ee820a991b95 91 */
Sissors 6:abfdd851218a 92 int convertTemperature(bool wait, devices device=all_devices);
Michael_ 2:ee820a991b95 93
pairmand 3:8f2b7f4940b5 94 /** This function will return the probe temperature. Approximately 10ms per
pairmand 3:8f2b7f4940b5 95 * probe to read its RAM, do CRC check and convert temperature on the LPC1768.
Michael_ 2:ee820a991b95 96 *
Michael_ 2:ee820a991b95 97 * @param scale, may be either 'c' or 'f'
Sissors 7:58b61681818f 98 * @returns temperature for that scale, or DS1820::invalid_conversion (-1000) if CRC error detected.
Michael_ 2:ee820a991b95 99 */
Michael_ 2:ee820a991b95 100 float temperature(char scale='c');
Michael_ 2:ee820a991b95 101
pairmand 3:8f2b7f4940b5 102 /** This function sets the temperature resolution for the DS18B20
pairmand 3:8f2b7f4940b5 103 * in the configuration register.
pairmand 3:8f2b7f4940b5 104 *
pairmand 3:8f2b7f4940b5 105 * @param a number between 9 and 12 to specify resolution
pairmand 3:8f2b7f4940b5 106 * @returns true if successful
pairmand 3:8f2b7f4940b5 107 */
Sissors 5:2cd4928e8147 108 bool setResolution(unsigned int resolution);
Michael_ 2:ee820a991b95 109
Michael_ 2:ee820a991b95 110 private:
Michael_ 2:ee820a991b95 111 bool _parasite_power;
Sissors 5:2cd4928e8147 112 bool _power_mosfet;
Sissors 5:2cd4928e8147 113 bool _power_polarity;
Sissors 5:2cd4928e8147 114
Sissors 5:2cd4928e8147 115 static char CRC_byte (char CRC, char byte );
Sissors 5:2cd4928e8147 116 static bool onewire_reset(DigitalInOut *pin);
Michael_ 2:ee820a991b95 117 void match_ROM();
Michael_ 2:ee820a991b95 118 void skip_ROM();
Sissors 5:2cd4928e8147 119 static bool search_ROM_routine(DigitalInOut *pin, char command, char *ROM_address);
Sissors 5:2cd4928e8147 120 static void onewire_bit_out (DigitalInOut *pin, bool bit_data);
Michael_ 2:ee820a991b95 121 void onewire_byte_out(char data);
Sissors 5:2cd4928e8147 122 static bool onewire_bit_in(DigitalInOut *pin);
Michael_ 2:ee820a991b95 123 char onewire_byte_in();
Sissors 5:2cd4928e8147 124 static bool ROM_checksum_error(char *_ROM_address);
Sissors 5:2cd4928e8147 125 bool RAM_checksum_error();
Sissors 5:2cd4928e8147 126 void read_RAM();
Sissors 5:2cd4928e8147 127 static bool unassignedProbe(DigitalInOut *pin, char *ROM_address);
Sissors 5:2cd4928e8147 128 void write_scratchpad(int data);
Sissors 5:2cd4928e8147 129 bool read_power_supply(devices device=this_device);
Michael_ 2:ee820a991b95 130
Michael_ 2:ee820a991b95 131 DigitalInOut _datapin;
Michael_ 2:ee820a991b95 132 DigitalOut _parasitepin;
Sissors 5:2cd4928e8147 133
Sissors 5:2cd4928e8147 134 char _ROM[8];
Sissors 5:2cd4928e8147 135 char RAM[9];
Sissors 5:2cd4928e8147 136
Sissors 5:2cd4928e8147 137 static LinkedList<node> probes;
Michael_ 2:ee820a991b95 138 };
Michael_ 2:ee820a991b95 139
Michael_ 2:ee820a991b95 140
Michael_ 2:ee820a991b95 141 #endif