#ifndef OneWire_h #define OneWire_h #include #if defined(__AVR__) #include #endif #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 0 #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 #ifndef FALSE #define FALSE 0 #endif #ifndef TRUE #define TRUE 1 #endif // 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_BASE_ATTR asm("r30") #define IO_REG_MASK_ATTR #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(__MK20DX128__) || defined(__MK20DX256__) || defined(__MK66FX1M0__) || defined(__MK64FX512__) #define PIN_TO_BASEREG(pin) (portOutputRegister(pin)) #define PIN_TO_BITMASK(pin) (1) #define IO_REG_TYPE uint8_t #define IO_REG_BASE_ATTR #define IO_REG_MASK_ATTR __attribute__ ((unused)) #define DIRECT_READ(base, mask) (*((base)+512)) #define DIRECT_MODE_INPUT(base, mask) (*((base)+640) = 0) #define DIRECT_MODE_OUTPUT(base, mask) (*((base)+640) = 1) #define DIRECT_WRITE_LOW(base, mask) (*((base)+256) = 1) #define DIRECT_WRITE_HIGH(base, mask) (*((base)+128) = 1) #elif defined(__MKL26Z64__) #define PIN_TO_BASEREG(pin) (portOutputRegister(pin)) #define PIN_TO_BITMASK(pin) (digitalPinToBitMask(pin)) #define IO_REG_TYPE uint8_t #define IO_REG_BASE_ATTR #define IO_REG_MASK_ATTR #define DIRECT_READ(base, mask) ((*((base)+16) & (mask)) ? 1 : 0) #define DIRECT_MODE_INPUT(base, mask) (*((base)+20) &= ~(mask)) #define DIRECT_MODE_OUTPUT(base, mask) (*((base)+20) |= (mask)) #define DIRECT_WRITE_LOW(base, mask) (*((base)+8) = (mask)) #define DIRECT_WRITE_HIGH(base, mask) (*((base)+4) = (mask)) #elif defined(__SAM3X8E__) || defined(__SAM3A8C__) || defined(__SAM3A4C__) // Arduino 1.5.1 may have a bug in delayMicroseconds() on Arduino Due. // http://arduino.cc/forum/index.php/topic,141030.msg1076268.html#msg1076268 // If you have trouble with OneWire on Arduino Due, please check the // status of delayMicroseconds() before reporting a bug in OneWire! #define PIN_TO_BASEREG(pin) (&(digitalPinToPort(pin)->PIO_PER)) #define PIN_TO_BITMASK(pin) (digitalPinToBitMask(pin)) #define IO_REG_TYPE uint32_t #define IO_REG_BASE_ATTR #define IO_REG_MASK_ATTR #define DIRECT_READ(base, mask) (((*((base)+15)) & (mask)) ? 1 : 0) #define DIRECT_MODE_INPUT(base, mask) ((*((base)+5)) = (mask)) #define DIRECT_MODE_OUTPUT(base, mask) ((*((base)+4)) = (mask)) #define DIRECT_WRITE_LOW(base, mask) ((*((base)+13)) = (mask)) #define DIRECT_WRITE_HIGH(base, mask) ((*((base)+12)) = (mask)) #ifndef PROGMEM #define PROGMEM #endif #ifndef pgm_read_byte #define pgm_read_byte(addr) (*(const uint8_t *)(addr)) #endif #elif defined(__PIC32MX__) #define PIN_TO_BASEREG(pin) (portModeRegister(digitalPinToPort(pin))) #define PIN_TO_BITMASK(pin) (digitalPinToBitMask(pin)) #define IO_REG_TYPE uint32_t #define IO_REG_BASE_ATTR #define IO_REG_MASK_ATTR #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 #elif defined(ARDUINO_ARCH_ESP8266) // Special note: I depend on the ESP community to maintain these definitions and // submit good pull requests. I can not answer any ESP questions or help you // resolve any problems related to ESP chips. Please do not contact me and please // DO NOT CREATE GITHUB ISSUES for ESP support. All ESP questions must be asked // on ESP community forums. #define PIN_TO_BASEREG(pin) ((volatile uint32_t*) GPO) #define PIN_TO_BITMASK(pin) (1 << pin) #define IO_REG_TYPE uint32_t #define IO_REG_BASE_ATTR #define IO_REG_MASK_ATTR #define DIRECT_READ(base, mask) ((GPI & (mask)) ? 1 : 0) //GPIO_IN_ADDRESS #define DIRECT_MODE_INPUT(base, mask) (GPE &= ~(mask)) //GPIO_ENABLE_W1TC_ADDRESS #define DIRECT_MODE_OUTPUT(base, mask) (GPE |= (mask)) //GPIO_ENABLE_W1TS_ADDRESS #define DIRECT_WRITE_LOW(base, mask) (GPOC = (mask)) //GPIO_OUT_W1TC_ADDRESS #define DIRECT_WRITE_HIGH(base, mask) (GPOS = (mask)) //GPIO_OUT_W1TS_ADDRESS #elif defined(ARDUINO_ARCH_ESP32) #include #define PIN_TO_BASEREG(pin) (0) #define PIN_TO_BITMASK(pin) (pin) #define IO_REG_TYPE uint32_t #define IO_REG_BASE_ATTR #define IO_REG_MASK_ATTR static inline __attribute__((always_inline)) IO_REG_TYPE directRead(IO_REG_TYPE pin) { if ( pin < 32 ) return (GPIO.in >> pin) & 0x1; else if ( pin < 40 ) return (GPIO.in1.val >> (pin - 32)) & 0x1; return 0; } static inline __attribute__((always_inline)) void directWriteLow(IO_REG_TYPE pin) { if ( pin < 32 ) GPIO.out_w1tc = ((uint32_t)1 << pin); else if ( pin < 34 ) GPIO.out1_w1tc.val = ((uint32_t)1 << (pin - 32)); } static inline __attribute__((always_inline)) void directWriteHigh(IO_REG_TYPE pin) { if ( pin < 32 ) GPIO.out_w1ts = ((uint32_t)1 << pin); else if ( pin < 34 ) GPIO.out1_w1ts.val = ((uint32_t)1 << (pin - 32)); } static inline __attribute__((always_inline)) void directModeInput(IO_REG_TYPE pin) { if ( digitalPinIsValid(pin) ) { #if ESP_IDF_VERSION_MAJOR < 4 // IDF 3.x ESP32/PICO-D4 uint32_t rtc_reg(rtc_gpio_desc[pin].reg); if ( rtc_reg ) // RTC pins PULL settings { ESP_REG(rtc_reg) = ESP_REG(rtc_reg) & ~(rtc_gpio_desc[pin].mux); ESP_REG(rtc_reg) = ESP_REG(rtc_reg) & ~(rtc_gpio_desc[pin].pullup | rtc_gpio_desc[pin].pulldown); } #elif ESP_IDF_VERSION_MAJOR > 3 // ESP32-S2 needs IDF 4.2 or later uint32_t rtc_reg(rtc_io_desc[pin].reg); if ( rtc_reg ) // RTC pins PULL settings { ESP_REG(rtc_reg) = ESP_REG(rtc_reg) & ~(rtc_io_desc[pin].mux); ESP_REG(rtc_reg) = ESP_REG(rtc_reg) & ~(rtc_io_desc[pin].pullup | rtc_io_desc[pin].pulldown); } #endif if ( pin < 32 ) GPIO.enable_w1tc = ((uint32_t)1 << pin); else GPIO.enable1_w1tc.val = ((uint32_t)1 << (pin - 32)); uint32_t pinFunction((uint32_t)2 << FUN_DRV_S); // what are the drivers? pinFunction |= FUN_IE; // input enable but required for output as well? pinFunction |= ((uint32_t)2 << MCU_SEL_S); ESP_REG(DR_REG_IO_MUX_BASE + esp32_gpioMux[pin].reg) = pinFunction; GPIO.pin[pin].val = 0; } } static inline __attribute__((always_inline)) void directModeOutput(IO_REG_TYPE pin) { if ( digitalPinIsValid(pin) && pin <= 33 ) // pins above 33 can be only inputs { #if ESP_IDF_VERSION_MAJOR < 4 // IDF 3.x ESP32/PICO-D4 uint32_t rtc_reg(rtc_gpio_desc[pin].reg); if ( rtc_reg ) // RTC pins PULL settings { ESP_REG(rtc_reg) = ESP_REG(rtc_reg) & ~(rtc_gpio_desc[pin].mux); ESP_REG(rtc_reg) = ESP_REG(rtc_reg) & ~(rtc_gpio_desc[pin].pullup | rtc_gpio_desc[pin].pulldown); } #elif ESP_IDF_VERSION_MAJOR > 3 // ESP32-S2 needs IDF 4.2 or later uint32_t rtc_reg(rtc_io_desc[pin].reg); if ( rtc_reg ) // RTC pins PULL settings { ESP_REG(rtc_reg) = ESP_REG(rtc_reg) & ~(rtc_io_desc[pin].mux); ESP_REG(rtc_reg) = ESP_REG(rtc_reg) & ~(rtc_io_desc[pin].pullup | rtc_io_desc[pin].pulldown); } #endif if ( pin < 32 ) GPIO.enable_w1ts = ((uint32_t)1 << pin); else // already validated to pins <= 33 GPIO.enable1_w1ts.val = ((uint32_t)1 << (pin - 32)); uint32_t pinFunction((uint32_t)2 << FUN_DRV_S); // what are the drivers? pinFunction |= FUN_IE; // input enable but required for output as well? pinFunction |= ((uint32_t)2 << MCU_SEL_S); ESP_REG(DR_REG_IO_MUX_BASE + esp32_gpioMux[pin].reg) = pinFunction; GPIO.pin[pin].val = 0; } } #define DIRECT_READ(base, pin) directRead(pin) #define DIRECT_WRITE_LOW(base, pin) directWriteLow(pin) #define DIRECT_WRITE_HIGH(base, pin) directWriteHigh(pin) #define DIRECT_MODE_INPUT(base, pin) directModeInput(pin) #define DIRECT_MODE_OUTPUT(base, pin) directModeOutput(pin) //#warning "ESP32 OneWire testing" #elif defined(__SAMD21G18A__) #define PIN_TO_BASEREG(pin) portModeRegister(digitalPinToPort(pin)) #define PIN_TO_BITMASK(pin) (digitalPinToBitMask(pin)) #define IO_REG_TYPE uint32_t #define IO_REG_BASE_ATTR #define IO_REG_MASK_ATTR #define DIRECT_READ(base, mask) (((*((base)+8)) & (mask)) ? 1 : 0) #define DIRECT_MODE_INPUT(base, mask) ((*((base)+1)) = (mask)) #define DIRECT_MODE_OUTPUT(base, mask) ((*((base)+2)) = (mask)) #define DIRECT_WRITE_LOW(base, mask) ((*((base)+5)) = (mask)) #define DIRECT_WRITE_HIGH(base, mask) ((*((base)+6)) = (mask)) #elif defined(RBL_NRF51822) #define PIN_TO_BASEREG(pin) (0) #define PIN_TO_BITMASK(pin) (pin) #define IO_REG_TYPE uint32_t #define IO_REG_BASE_ATTR #define IO_REG_MASK_ATTR #define DIRECT_READ(base, pin) nrf_gpio_pin_read(pin) #define DIRECT_WRITE_LOW(base, pin) nrf_gpio_pin_clear(pin) #define DIRECT_WRITE_HIGH(base, pin) nrf_gpio_pin_set(pin) #define DIRECT_MODE_INPUT(base, pin) nrf_gpio_cfg_input(pin, NRF_GPIO_PIN_NOPULL) #define DIRECT_MODE_OUTPUT(base, pin) nrf_gpio_cfg_output(pin) #elif defined(__arc__) /* Arduino101/Genuino101 specifics */ #include "scss_registers.h" #include "portable.h" #include "avr/pgmspace.h" #define GPIO_ID(pin) (g_APinDescription[pin].ulGPIOId) #define GPIO_TYPE(pin) (g_APinDescription[pin].ulGPIOType) #define GPIO_BASE(pin) (g_APinDescription[pin].ulGPIOBase) #define DIR_OFFSET_SS 0x01 #define DIR_OFFSET_SOC 0x04 #define EXT_PORT_OFFSET_SS 0x0A #define EXT_PORT_OFFSET_SOC 0x50 /* GPIO registers base address */ #define PIN_TO_BASEREG(pin) ((volatile uint32_t *)g_APinDescription[pin].ulGPIOBase) #define PIN_TO_BITMASK(pin) pin #define IO_REG_TYPE uint32_t #define IO_REG_BASE_ATTR #define IO_REG_MASK_ATTR static inline __attribute__((always_inline)) IO_REG_TYPE directRead(volatile IO_REG_TYPE *base, IO_REG_TYPE pin) { IO_REG_TYPE ret; if (SS_GPIO == GPIO_TYPE(pin)) { ret = READ_ARC_REG(((IO_REG_TYPE)base + EXT_PORT_OFFSET_SS)); } else { ret = MMIO_REG_VAL_FROM_BASE((IO_REG_TYPE)base, EXT_PORT_OFFSET_SOC); } return ((ret >> GPIO_ID(pin)) & 0x01); } static inline __attribute__((always_inline)) void directModeInput(volatile IO_REG_TYPE *base, IO_REG_TYPE pin) { if (SS_GPIO == GPIO_TYPE(pin)) { WRITE_ARC_REG(READ_ARC_REG((((IO_REG_TYPE)base) + DIR_OFFSET_SS)) & ~(0x01 << GPIO_ID(pin)), ((IO_REG_TYPE)(base) + DIR_OFFSET_SS)); } else { MMIO_REG_VAL_FROM_BASE((IO_REG_TYPE)base, DIR_OFFSET_SOC) &= ~(0x01 << GPIO_ID(pin)); } } static inline __attribute__((always_inline)) void directModeOutput(volatile IO_REG_TYPE *base, IO_REG_TYPE pin) { if (SS_GPIO == GPIO_TYPE(pin)) { WRITE_ARC_REG(READ_ARC_REG(((IO_REG_TYPE)(base) + DIR_OFFSET_SS)) | (0x01 << GPIO_ID(pin)), ((IO_REG_TYPE)(base) + DIR_OFFSET_SS)); } else { MMIO_REG_VAL_FROM_BASE((IO_REG_TYPE)base, DIR_OFFSET_SOC) |= (0x01 << GPIO_ID(pin)); } } static inline __attribute__((always_inline)) void directWriteLow(volatile IO_REG_TYPE *base, IO_REG_TYPE pin) { if (SS_GPIO == GPIO_TYPE(pin)) { WRITE_ARC_REG(READ_ARC_REG(base) & ~(0x01 << GPIO_ID(pin)), base); } else { MMIO_REG_VAL(base) &= ~(0x01 << GPIO_ID(pin)); } } static inline __attribute__((always_inline)) void directWriteHigh(volatile IO_REG_TYPE *base, IO_REG_TYPE pin) { if (SS_GPIO == GPIO_TYPE(pin)) { WRITE_ARC_REG(READ_ARC_REG(base) | (0x01 << GPIO_ID(pin)), base); } else { MMIO_REG_VAL(base) |= (0x01 << GPIO_ID(pin)); } } #define DIRECT_READ(base, pin) directRead(base, pin) #define DIRECT_MODE_INPUT(base, pin) directModeInput(base, pin) #define DIRECT_MODE_OUTPUT(base, pin) directModeOutput(base, pin) #define DIRECT_WRITE_LOW(base, pin) directWriteLow(base, pin) #define DIRECT_WRITE_HIGH(base, pin) directWriteHigh(base, pin) #elif defined(__riscv) /* * Tested on highfive1 * * Stable results are achieved operating in the * two high speed modes of the highfive1. It * seems to be less reliable in slow mode. */ #define PIN_TO_BASEREG(pin) (0) #define PIN_TO_BITMASK(pin) digitalPinToBitMask(pin) #define IO_REG_TYPE uint32_t #define IO_REG_BASE_ATTR #define IO_REG_MASK_ATTR static inline __attribute__((always_inline)) IO_REG_TYPE directRead(IO_REG_TYPE mask) { return ((GPIO_REG(GPIO_INPUT_VAL) & mask) != 0) ? 1 : 0; } static inline __attribute__((always_inline)) void directModeInput(IO_REG_TYPE mask) { GPIO_REG(GPIO_OUTPUT_XOR) &= ~mask; GPIO_REG(GPIO_IOF_EN) &= ~mask; GPIO_REG(GPIO_INPUT_EN) |= mask; GPIO_REG(GPIO_OUTPUT_EN) &= ~mask; } static inline __attribute__((always_inline)) void directModeOutput(IO_REG_TYPE mask) { GPIO_REG(GPIO_OUTPUT_XOR) &= ~mask; GPIO_REG(GPIO_IOF_EN) &= ~mask; GPIO_REG(GPIO_INPUT_EN) &= ~mask; GPIO_REG(GPIO_OUTPUT_EN) |= mask; } static inline __attribute__((always_inline)) void directWriteLow(IO_REG_TYPE mask) { GPIO_REG(GPIO_OUTPUT_VAL) &= ~mask; } static inline __attribute__((always_inline)) void directWriteHigh(IO_REG_TYPE mask) { GPIO_REG(GPIO_OUTPUT_VAL) |= mask; } #define DIRECT_READ(base, mask) directRead(mask) #define DIRECT_WRITE_LOW(base, mask) directWriteLow(mask) #define DIRECT_WRITE_HIGH(base, mask) directWriteHigh(mask) #define DIRECT_MODE_INPUT(base, mask) directModeInput(mask) #define DIRECT_MODE_OUTPUT(base, mask) directModeOutput(mask) #else #define PIN_TO_BASEREG(pin) (0) #define PIN_TO_BITMASK(pin) (pin) #define IO_REG_TYPE unsigned int #define IO_REG_BASE_ATTR #define IO_REG_MASK_ATTR #define DIRECT_READ(base, pin) digitalRead(pin) #define DIRECT_WRITE_LOW(base, pin) digitalWrite(pin, LOW) #define DIRECT_WRITE_HIGH(base, pin) digitalWrite(pin, HIGH) #define DIRECT_MODE_INPUT(base, pin) pinMode(pin,INPUT) #define DIRECT_MODE_OUTPUT(base, pin) pinMode(pin,OUTPUT) #warning "OneWire. Fallback mode. Using API calls for pinMode,digitalRead and digitalWrite. Operation of this library is not guaranteed on this architecture." #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(const 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(); // Setup the search to find the device type 'family_code' on the next call // to search(*newAddr) if it is present. void target_search(uint8_t family_code); // 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, bool search_mode = true); #endif #if ONEWIRE_CRC // Compute a Dallas Semiconductor 8 bit CRC, these are used in the // ROM and scratchpad registers. static uint8_t crc8(const 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. // @param crc - The crc starting value (optional) // @return True, iff the CRC matches. static bool check_crc16(const uint8_t* input, uint16_t len, const uint8_t* inverted_crc, uint16_t crc = 0); // 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. // @param crc - The crc starting value (optional) // @return The CRC16, as defined by Dallas Semiconductor. static uint16_t crc16(const uint8_t* input, uint16_t len, uint16_t crc = 0); #endif #endif }; #endif