teste de publish
Fork of DS1820 by
DS1820.h
- Committer:
- Michael_
- Date:
- 2011-12-15
- Revision:
- 2:ee820a991b95
- Parent:
- 1:6a427f54e82c
- Child:
- 3:8f2b7f4940b5
File content as of revision 2:ee820a991b95:
/* mbed DS1820 Library, for the Dallas (Maxim) 1-Wire Digital Thermometer * Copyright (c) 2010, Michael Hagberg Michael@RedBoxCode.com * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #ifndef MBED_DS1820_H #define MBED_DS1820_H #include "mbed.h" // ****** THIS GLOBAL VARIABLES MUST BE DEFINED IN main.cpp // Global variables shared between all DS1820 objects //bool DS1820_done_flag; //int DS1820_last_descrepancy; //char DS1820_search_ROM[8]; /** DS1820 Dallas 1-Wire Temperature Probe * * Example: * @code * #include "mbed.h" * * #include "TextLCD.h" * #include "DS1820.h" * * TextLCD lcd(p25, p26, p21, p22, p23, p24, TextLCD::LCD16x2); // rs, e, d0-d3, layout * * const int MAX_PROBES = 16; * DS1820* probe[MAX_PROBES]; * * int main() { * int i; * int devices_found=0; * // Initialize the probe array to DS1820 objects * for (i = 0; i < MAX_PROBES; i++) * probe[i] = new DS1820(p27); * // Initialize global state variables * probe[0]->search_ROM_setup(); * // Loop to find all devices on the data line * while (probe[devices_found]->search_ROM() and devices_found<MAX_PROBES-1) * devices_found++; * // If maximum number of probes are found, * // bump the counter to include the last array entry * if (probe[devices_found]->ROM[0] != 0xFF) * devices_found++; * * lcd.cls(); * if (devices_found==0) * lcd.printf("No devices found"); * else { * while (true) { * probe[0]->convert_temperature(DS1820::all_devices); * lcd.cls(); * for (i=0; i<devices_found; i++) { * lcd.printf("%3.1f ",probe[i]->temperature('f')); * } * } * } * } * @endcode */ class DS1820 { public: enum devices{ this_device, // command applies to only this device all_devices }; // command applies to all devices /** Create a probe object connected to the specified pins * * @param data_pin DigitalInOut pin for the data bus * @param power_pin DigitalOut pin to control the power MOSFET */ DS1820(PinName data_pin, PinName power_pin); // Constructor with parasite power pin /** Create a probe object connected to the specified pin * this is used when all probes are externally powered * * @param data_pin DigitalInOut pin for the data bus */ DS1820(PinName data_pin); /** ROM is a copy of the internal DS1820's ROM * It is created during the search_ROM() or search_alarm() commands * * ROM[0] is the Dallas Family Code * ROM[1] thru ROM[6] is the 48-bit unique serial number * ROM[7] is the device CRC */ char ROM[8]; #define FAMILY_CODE ROM[0] #define FAMILY_CODE_DS1820 0x10 #define FAMILY_CODE_DS18S20 0x10 #define FAMILY_CODE_DS18B20 0x28 /** RAM is a copy of the internal DS1820's RAM * It's updated during the read_RAM() command * which is automaticaly called from any function * using the RAM values. */ char RAM[9]; /* This function copies the DS1820's RAM into the object's * RAM[]. */ void read_RAM(); /** This routine initializes the global variables used in * the search_ROM() and search_alarm() funtions. It should * be called once before looping to find devices. */ void search_ROM_setup(); /** This routine will search for an unidentified device * on the bus. It uses the variables in search_ROM_setup * to remember the pervious ROM address found. * It will return FALSE if there were no new devices * discovered on the bus. */ bool search_ROM(); /** This routine will search for an unidentified device * which has the temperature alarm bit set. It uses the * variables in search_ROM_setup to remember the pervious * ROM address found. It will return FALSE if there were * no new devices with alarms discovered on the bus. */ bool search_alarm(); /** This routine will read the ROM (Family code, serial number * and Checksum) from a dedicated device on the bus. * * NOTE: This command can only be used when there is only one * DS1820 on the bus. If this command is used when there * is more than one slave present on the bus, a data * collision will occur when all the DS1820s attempt to * respond at the same time. */ void read_ROM(); /** This routine will initiate the temperature conversion within * a DS1820. There is a built in 750ms delay to allow the * conversion to complete. * * To update all probes on the bus, use a statement such as this: * probe[0]->convert_temperature(DS1820::all_devices); * * @param allows the fnction to apply to a specific device or * to all devices on the 1-Wire bus. */ void convert_temperature(devices device=this_device); /** This function will return the probe temperature. This function * uses the count remainding values to interpolate the temperature * to about 1/150th of a degree. Whereas the probe is not spec to * that precision. It does seem to give a smooth reading to the * tenth of a degree. * * @param scale, may be either 'c' or 'f' * @returns temperature for that scale */ float temperature(char scale='c'); /** This function calculates the ROM checksum and compares it to the * CRC value stored in ROM[7]. * * @returns true if the checksum matches, otherwise false. */ bool ROM_checksum_error(); /** This function calculates the RAM checksum and compares it to the * CRC value stored in RAM[8]. * * @returns true if the checksum matches, otherwise false. */ bool RAM_checksum_error(); /** This function returns the values stored in the temperature * alarm registers. * * @returns a 16 bit integer of TH (upper byte) and TL (lower byte). */ bool set_configuration_bits(unsigned int resolution); /** This function sets the temperature resolution for the DS18B20 * in the configuration register. * * @param a number between 9 and 12 to specify the resolution * @returns true if successful */ int read_scratchpad(); /** This function will store the passed data into the DS1820's RAM. * Note: It does NOT save the data to the EEPROM for retention * during cycling the power off and on. * * @param a 16 bit integer of TH (upper byte) and TL (lower byte). */ void write_scratchpad(int data); /** This function will transfer the TH and TL registers from the * DS1820's RAM into the EEPROM. * Note: There is a built in 10ms delay to allow for the * completion of the EEPROM write cycle. * * @param allows the fnction to apply to a specific device or * to all devices on the 1-Wire bus. */ void store_scratchpad(devices device=this_device); /** This function will copy the stored values from the EEPROM * into the DS1820's RAM locations for TH and TL. * * @param allows the function to apply to a specific device or * to all devices on the 1-Wire bus. */ int recall_scratchpad(devices device=this_device); /** This function will return the type of power supply for * a specific device. It can also be used to query all devices * looking for any device that is parasite powered. * * @returns true if the device (or all devices) are Vcc powered, * returns false if the device (or ANY device) is parasite powered. */ bool read_power_supply(devices device=this_device); private: bool _parasite_power; char CRC_byte (char CRC, char byte ); bool onewire_reset(); void match_ROM(); void skip_ROM(); bool search_ROM_routine(char command); void onewire_bit_out (bool bit_data); void onewire_byte_out(char data); bool onewire_bit_in(); char onewire_byte_in(); protected: DigitalInOut _datapin; DigitalOut _parasitepin; }; #endif