Onewire.h

00001 #ifndef Onewire_h
00002 #define Onewire_h
00003 
00004 #include "mbed.h"
00005 
00006 #define ONEWIRE_ADDR_BYTES 8
00007 
00008 const int ONEWIRE_OK = 0;
00009 const int ONEWIRE_FAIL_STUCK_LOW = 1;
00010 const int ONEWIRE_SEARCH_ALL_DONE = 2;
00011 const int ONEWIRE_SEARCH_INIT_FAIL = 3;
00012 const int ONEWIRE_SEARCH_NOT_FOUND = 4;
00013 const int ONEWIRE_SEARCH_COMP_BIT_ERR = 5;
00014 
00015 class Onewire
00016 {
00017 
00018 public:    
00019     Onewire(PinName oneBus);
00020     void writeBit(int bit);
00021     int readBit();
00022     int init();
00023     int readByte();
00024     void writeByte(char data);
00025     unsigned char CRC(unsigned char* addr, unsigned char len);
00026     char* GetErrorStr(int errCode);
00027 
00028     // Clear the search state so that if will start from the beginning again.
00029     void reset_search();
00030     // Look for the next device.
00031     // Returns 
00032     // ONEWIRE_OK if a new address has been returned.
00033     // ONEWIRE_SEARCH_ALL_DONE = all devices found
00034     // ONEWIRE_SEARCH_INIT_FAIL = failed to init
00035     // ONEWIRE_SEARCH_NOT_FOUND = no devices found
00036     // It might be a good idea to check the CRC to make sure you didn't
00037     // get garbage.  The order is deterministic. You will always get
00038     // the same devices in the same order.
00039     uint8_t search(uint8_t *newAddr);    
00040     
00041 private:
00042     DigitalInOut oneBus_;
00043   
00044     // search state
00045     unsigned char _search_ROM_NO[8];
00046     uint8_t _search_LastDiscrepancy;
00047     uint8_t _search_LastFamilyDiscrepancy;
00048     uint8_t _search_LastDeviceFlag;
00049 };
00050 #endif