MM2WayRanging.h

00001 #ifndef MM2WAYRANGING_H
00002 #define MM2WAYRANGING_H
00003  
00004 #include "mbed.h"
00005 #include "DW1000.h"
00006 
00007 
00008 #define TIMEUNITS_TO_US       (1/(128*499.2))               // conversion between the decawave timeunits (ca 15.65ps) to microseconds.
00009 #define US_TO_TIMEUNITS       (128*499.2)                   // conversion between microseconds to the decawave timeunits (ca 15.65ps).
00010 #define MMRANGING_2POWER40    1099511627776                 // decimal value of 2^40 to correct timeroverflow between timestamps
00011  
00012 //Predefined delay for the critical answers in the ranging algorithm
00013 //HAS TO BE BIGGER THAN THE PROCESSING TIME OF THE FRAME ON THE NODE
00014 #define ANSWER_DELAY_US             2500                                    //2500 works for 110kbps, 900 for 6.8Mbps
00015 #define ANSWER_DELAY_TIMEUNITS      ANSWER_DELAY_US * (128*499.2)
00016 
00017 class MM2WayRanging {
00018  
00019 public:
00020     MM2WayRanging(DW1000& DW);
00021  
00022     bool beacon_requestRanging();
00023     void anchor_standbyToRange();
00024  
00025     bool isBeacon;
00026     uint8_t address;                // Identifies the nodes as source and destination in rangingframes
00027     bool overflow;                  // TRUE if counter overflows while ranging
00028  
00029 private:
00030     DW1000& dw;
00031     Timer LocalTimer;
00032  
00033     bool waitForFrameTX(float time_before);
00034     bool waitForFrameRX(float time_before);
00035     void callbackRX();
00036     void callbackTX();
00037     
00038     void beacon_ready_Send();
00039     void anchor_to_beacon_Send(uint8_t destination);
00040     void beacon_to_anchor_response_Send(uint8_t destination, uint64_t rxTimestamp);
00041  
00042     //void correctReceiverTimestamps(uint8_t source);
00043     //void correctSenderTimestamps(uint8_t source);
00044  
00045     enum FrameType{
00046         BEACON_READY=1,
00047         ANCHOR_TO_BEACON_PING,
00048         BEACON_TO_ANCHOR_RESPONSE
00049     };
00050  
00051     //the packed attribute makes sure the types only use their respective size in memory (8 bit for uint8_t), otherwise they would always use 32 bit
00052     //IT IS A GCC SPECIFIC DIRECTIVE
00053     struct __attribute__((packed, aligned(1))) RangingFrame {
00054         uint8_t source;
00055         uint8_t destination;
00056         uint8_t type;
00057     };
00058  
00059     RangingFrame rangingFrame;                  // buffer in class for sending a frame (not made locally because then we can recall in the interrupt what was sent)
00060     RangingFrame receivedFrame;
00061     
00062     uint64_t RxTimestamp;
00063     uint64_t rangingTxTimestamp[5];
00064     uint64_t rangingRxTimestamp[5];
00065     uint64_t rangingTOF[5];
00066     float rangingDistance[5];
00067 };
00068 #endif