MMRanging.h

00001 // by Matthias Grob & Manuel Stalder - ETH Zürich - 2015
00002 
00003 #ifndef MMRANGING_H
00004 #define MMRANGING_H
00005 
00006 #include "mbed.h"
00007 #include "DW1000.h"
00008 
00009 #define MMRANGING_TIMEUNIT_US       1/(128*499.2)               // conversion between LSB of TX and RX timestamps and microseconds
00010 #define MMRANGING_TIMEUNIT_NS       1000/(128*499.2)            // conversion between LSB of TX and RX timestamps and nanoseconds
00011 
00012 #define MMRANGING_2POWER40          1099511627776               // decimal value of 2^40 to correct timeroverflow between timestamps
00013 
00014 //#define EVENTS                                                // to see debug output of occurring interrupt callbacks
00015 
00016 class MMRanging {
00017     public:
00018         MMRanging(DW1000& DW);
00019         void requestRanging(uint8_t destination);
00020         void requestRangingAll();
00021     //private:
00022         DW1000& dw;
00023         Timer LocalTimer;
00024         
00025         void callbackRX();
00026         void callbackTX();
00027         void sendRangingframe(uint8_t destination, uint8_t sequence_number, uint8_t type, uint64_t time_difference_receiver);
00028         uint64_t timeDifference40Bit(uint64_t early, uint64_t late); // Method to calculate the difference between two 40-Bit timestamps correcting timer overflow reset occurring between the timestamps
00029         
00030         uint8_t address;                        // Identifies the nodes as source and destination in rangingframes
00031         //struct __attribute__((packed, aligned(1))) rangingframe {         // TODO: avoid structure padding, 32-Bit enough for time_difference_receiver  =>  8 Byte per frame instead of 16
00032         struct rangingframe {
00033             uint8_t source;
00034             uint8_t destination;
00035             uint8_t sequence_number;
00036             uint8_t type;
00037             uint64_t time_difference_receiver;
00038         };
00039         
00040         rangingframe TX;                        // buffer in class for sending a frame (not made locally because then we can recall in the interrupt what was sent)
00041         uint64_t rangingtimingsSender[10][2];
00042         uint64_t rangingtimingsReceiver[10][2];
00043         bool acknowledgement[10];               // flag to indicate if ranging has succeeded
00044         uint64_t tofs[10];                      // Array containing time of flights for each node (index is address of node)
00045         float roundtriptimes[10];               // Array containing the round trip times to the anchors or the timeout which occured
00046         float distances[10];                    // Array containing the finally calculated Distances to the anchors
00047         
00048         // draft for first test
00049         bool receiver;
00050         int event_i;
00051         char event[10][20];
00052         uint8_t counter;
00053 };
00054 
00055 #endif