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