255 lines
9.9 KiB
C++
255 lines
9.9 KiB
C++
#ifndef OneWire_h
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#define OneWire_h
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#include <inttypes.h>
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#if ARDUINO >= 100
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#include "Arduino.h" // for delayMicroseconds, digitalPinToBitMask, etc
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#else
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#include "WProgram.h" // for delayMicroseconds
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#include "pins_arduino.h" // for digitalPinToBitMask, etc
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#endif
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// You can exclude certain features from OneWire. In theory, this
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// might save some space. In practice, the compiler automatically
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// removes unused code (technically, the linker, using -fdata-sections
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// and -ffunction-sections when compiling, and Wl,--gc-sections
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// when linking), so most of these will not result in any code size
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// reduction. Well, unless you try to use the missing features
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// and redesign your program to not need them! ONEWIRE_CRC8_TABLE
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// is the exception, because it selects a fast but large algorithm
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// or a small but slow algorithm.
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// you can exclude onewire_search by defining that to 0
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#ifndef ONEWIRE_SEARCH
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#define ONEWIRE_SEARCH 1
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#endif
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// You can exclude CRC checks altogether by defining this to 0
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#ifndef ONEWIRE_CRC
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#define ONEWIRE_CRC 1
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#endif
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// Select the table-lookup method of computing the 8-bit CRC
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// by setting this to 1. The lookup table enlarges code size by
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// about 250 bytes. It does NOT consume RAM (but did in very
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// old versions of OneWire). If you disable this, a slower
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// but very compact algorithm is used.
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#ifndef ONEWIRE_CRC8_TABLE
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#define ONEWIRE_CRC8_TABLE 1
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#endif
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// You can allow 16-bit CRC checks by defining this to 1
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// (Note that ONEWIRE_CRC must also be 1.)
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#ifndef ONEWIRE_CRC16
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#define ONEWIRE_CRC16 1
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#endif
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#define FALSE 0
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#define TRUE 1
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// Platform specific I/O definitions
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#if defined(__AVR__)
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#define PIN_TO_BASEREG(pin) (portInputRegister(digitalPinToPort(pin)))
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#define PIN_TO_BITMASK(pin) (digitalPinToBitMask(pin))
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#define IO_REG_TYPE uint8_t
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#define IO_REG_ASM asm("r30")
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#define DIRECT_READ(base, mask) (((*(base)) & (mask)) ? 1 : 0)
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#define DIRECT_MODE_INPUT(base, mask) ((*((base)+1)) &= ~(mask))
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#define DIRECT_MODE_OUTPUT(base, mask) ((*((base)+1)) |= (mask))
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#define DIRECT_WRITE_LOW(base, mask) ((*((base)+2)) &= ~(mask))
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#define DIRECT_WRITE_HIGH(base, mask) ((*((base)+2)) |= (mask))
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#elif defined(__MK20DX128__) || defined(__MK20DX256__)
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#define PIN_TO_BASEREG(pin) (portOutputRegister(pin))
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#define PIN_TO_BITMASK(pin) (1)
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#define IO_REG_TYPE uint8_t
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#define IO_REG_ASM
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#define DIRECT_READ(base, mask) (*((base)+512))
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#define DIRECT_MODE_INPUT(base, mask) (*((base)+640) = 0)
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#define DIRECT_MODE_OUTPUT(base, mask) (*((base)+640) = 1)
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#define DIRECT_WRITE_LOW(base, mask) (*((base)+256) = 1)
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#define DIRECT_WRITE_HIGH(base, mask) (*((base)+128) = 1)
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#elif defined(__SAM3X8E__)
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// Arduino 1.5.1 may have a bug in delayMicroseconds() on Arduino Due.
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// http://arduino.cc/forum/index.php/topic,141030.msg1076268.html#msg1076268
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// If you have trouble with OneWire on Arduino Due, please check the
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// status of delayMicroseconds() before reporting a bug in OneWire!
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#define PIN_TO_BASEREG(pin) (&(digitalPinToPort(pin)->PIO_PER))
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#define PIN_TO_BITMASK(pin) (digitalPinToBitMask(pin))
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#define IO_REG_TYPE uint32_t
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#define IO_REG_ASM
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#define DIRECT_READ(base, mask) (((*((base)+15)) & (mask)) ? 1 : 0)
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#define DIRECT_MODE_INPUT(base, mask) ((*((base)+5)) = (mask))
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#define DIRECT_MODE_OUTPUT(base, mask) ((*((base)+4)) = (mask))
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#define DIRECT_WRITE_LOW(base, mask) ((*((base)+13)) = (mask))
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#define DIRECT_WRITE_HIGH(base, mask) ((*((base)+12)) = (mask))
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#ifndef PROGMEM
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#define PROGMEM
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#endif
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#ifndef pgm_read_byte
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#define pgm_read_byte(addr) (*(const uint8_t *)(addr))
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#endif
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#elif defined(__PIC32MX__)
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#define PIN_TO_BASEREG(pin) (portModeRegister(digitalPinToPort(pin)))
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#define PIN_TO_BITMASK(pin) (digitalPinToBitMask(pin))
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#define IO_REG_TYPE uint32_t
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#define IO_REG_ASM
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#define DIRECT_READ(base, mask) (((*(base+4)) & (mask)) ? 1 : 0) //PORTX + 0x10
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#define DIRECT_MODE_INPUT(base, mask) ((*(base+2)) = (mask)) //TRISXSET + 0x08
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#define DIRECT_MODE_OUTPUT(base, mask) ((*(base+1)) = (mask)) //TRISXCLR + 0x04
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#define DIRECT_WRITE_LOW(base, mask) ((*(base+8+1)) = (mask)) //LATXCLR + 0x24
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#define DIRECT_WRITE_HIGH(base, mask) ((*(base+8+2)) = (mask)) //LATXSET + 0x28
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#else
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/*
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Fallback to Arduino GPIO API calls for all other architectures.
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Operation can't be guaranteed using API calls, as the bus timings may be incorrect on some slower architectures.
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Notes.
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BASEREG is not used, and hence the result of the macro is 0 (zero)
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IO_REG_TYPE has been set to a generic data type of unsigned int , which should be available on most architectures
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IO_REG_ASM is not used
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PIN_TO_BITMASK returns the pin number, hence the bitmask private variable will be used to store the pin number rather than the bit mask,
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This is a minor hack as the variable will not contain the item advertised by its name.
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*/
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#define PIN_TO_BASEREG(pin) (0)
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#define PIN_TO_BITMASK(pin) ( pin )
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#define IO_REG_TYPE unsigned int
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#define IO_REG_ASM
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#define DIRECT_READ(base, pin) digitalRead(pin)
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#define DIRECT_WRITE_LOW(base, pin) digitalWrite(pin, LOW)
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#define DIRECT_WRITE_HIGH(base, pin) digitalWrite(pin, HIGH)
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#define DIRECT_MODE_INPUT(base, pin) pinMode(pin,INPUT)
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#define DIRECT_MODE_OUTPUT(base, pin) pinMode(pin,OUTPUT)
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#warning "OneWire. Fallback mode. Using API calls for pinMode,digitalRead and digitalWrite. Operation of this library is not guaranteed on this architecture."
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#endif
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class OneWire
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{
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private:
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IO_REG_TYPE bitmask;
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volatile IO_REG_TYPE *baseReg;
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#if ONEWIRE_SEARCH
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// global search state
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unsigned char ROM_NO[8];
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uint8_t LastDiscrepancy;
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uint8_t LastFamilyDiscrepancy;
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uint8_t LastDeviceFlag;
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#endif
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public:
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OneWire( uint8_t pin);
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// Perform a 1-Wire reset cycle. Returns 1 if a device responds
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// with a presence pulse. Returns 0 if there is no device or the
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// bus is shorted or otherwise held low for more than 250uS
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uint8_t reset(void);
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// Issue a 1-Wire rom select command, you do the reset first.
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void select(const uint8_t rom[8]);
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// Issue a 1-Wire rom skip command, to address all on bus.
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void skip(void);
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// Write a byte. If 'power' is one then the wire is held high at
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// the end for parasitically powered devices. You are responsible
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// for eventually depowering it by calling depower() or doing
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// another read or write.
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void write(uint8_t v, uint8_t power = 0);
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void write_bytes(const uint8_t *buf, uint16_t count, bool power = 0);
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// Read a byte.
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uint8_t read(void);
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void read_bytes(uint8_t *buf, uint16_t count);
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// Write a bit. The bus is always left powered at the end, see
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// note in write() about that.
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void write_bit(uint8_t v);
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// Read a bit.
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uint8_t read_bit(void);
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// Stop forcing power onto the bus. You only need to do this if
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// you used the 'power' flag to write() or used a write_bit() call
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// and aren't about to do another read or write. You would rather
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// not leave this powered if you don't have to, just in case
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// someone shorts your bus.
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void depower(void);
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#if ONEWIRE_SEARCH
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// Clear the search state so that if will start from the beginning again.
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void reset_search();
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// Setup the search to find the device type 'family_code' on the next call
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// to search(*newAddr) if it is present.
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void target_search(uint8_t family_code);
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// Look for the next device. Returns 1 if a new address has been
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// returned. A zero might mean that the bus is shorted, there are
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// no devices, or you have already retrieved all of them. It
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// might be a good idea to check the CRC to make sure you didn't
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// get garbage. The order is deterministic. You will always get
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// the same devices in the same order.
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uint8_t search(uint8_t *newAddr);
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#endif
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#if ONEWIRE_CRC
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// Compute a Dallas Semiconductor 8 bit CRC, these are used in the
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// ROM and scratchpad registers.
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static uint8_t crc8(const uint8_t *addr, uint8_t len);
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#if ONEWIRE_CRC16
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// Compute the 1-Wire CRC16 and compare it against the received CRC.
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// Example usage (reading a DS2408):
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// // Put everything in a buffer so we can compute the CRC easily.
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// uint8_t buf[13];
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// buf[0] = 0xF0; // Read PIO Registers
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// buf[1] = 0x88; // LSB address
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// buf[2] = 0x00; // MSB address
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// WriteBytes(net, buf, 3); // Write 3 cmd bytes
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// ReadBytes(net, buf+3, 10); // Read 6 data bytes, 2 0xFF, 2 CRC16
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// if (!CheckCRC16(buf, 11, &buf[11])) {
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// // Handle error.
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// }
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//
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// @param input - Array of bytes to checksum.
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// @param len - How many bytes to use.
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// @param inverted_crc - The two CRC16 bytes in the received data.
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// This should just point into the received data,
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// *not* at a 16-bit integer.
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// @param crc - The crc starting value (optional)
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// @return True, iff the CRC matches.
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static bool check_crc16(const uint8_t* input, uint16_t len, const uint8_t* inverted_crc, uint16_t crc = 0);
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// Compute a Dallas Semiconductor 16 bit CRC. This is required to check
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// the integrity of data received from many 1-Wire devices. Note that the
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// CRC computed here is *not* what you'll get from the 1-Wire network,
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// for two reasons:
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// 1) The CRC is transmitted bitwise inverted.
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// 2) Depending on the endian-ness of your processor, the binary
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// representation of the two-byte return value may have a different
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// byte order than the two bytes you get from 1-Wire.
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// @param input - Array of bytes to checksum.
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// @param len - How many bytes to use.
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// @param crc - The crc starting value (optional)
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// @return The CRC16, as defined by Dallas Semiconductor.
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static uint16_t crc16(const uint8_t* input, uint16_t len, uint16_t crc = 0);
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#endif
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#endif
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};
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#endif
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