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# DS28CM00

Arduino library for I2C DS28CM00 unique identification chip.  \[48 bit\]


## Description

THe DS28CM00 IC has a 64 bit address consisting of one type byte, 0x50, 6 bytes unique serial and a CRC
over the previous 7 bytes. This results in an 48 bits unique ID giving 281.474.976.710.656 combinations.
If that number is not unique enough, you could use 2 or more of them with an I2C multiplexer.

The DS28CM00 IC has the same addressing scheme as the better known DS18B20, except for the type byte.
Therefore one could use an DS18B20 as an unique ID chip in a similar way and getting a temperature sensor
as bonus. 

The DS28CM00 can work in 2 modes, I2C and SMBus mode. Check datasheet for details.


## Interface


### Constructor

- **DS28CM00(TwoWire \*wire = &Wire)** Constructor, with default Wire as I2C bus.
- **DS28CM00(uint8_t dataPin, uint8_t clockPin)** Constructor for ESP32, ESP8266 et al.


### public

- **void begin()** initializes I2C bus, sets default DS28CM00_I2C_MODE.
- **bool getUID(uint8_t \*serial)** get unique 8 bytes serial number or error.
Returns false if action failed.
- **bool setI2CMode()** set DS28CM00_I2C_MODE (0x00). Returns false if action failed.
- **bool setSMBusMode()** set DS28CM00_SMBUS_MODE (0x01). Returns false if action failed.
- **bool getMode(uint8_t &mode)** returns mode set above. Returns false if action failed.


## Operation

See examples.

The class is not tested extensively e.g. with ESP32 / ESP8266.
An example sketch for ESP32 exist and compiles. Feedback welcome.


## Future

#### should
- only extend on request / bugs
- measure performance I2C 400 500 600 kHz ...

#### could
- cache the serial? (costs 8 bytes)
  - If (defined DS28_CACHE) ...

#### wont
- **bool getUID4()** to read only 4 bytes to improve performance. Possible?
- **bool getUID(4)** number of bytes as parameter?
- **uint8_t getError()** add error handling? - I2C; #bytes; mode; ...(too much for simple device)