Diff: MM2WayRanging/MM2WayRanging.h

Revision:

0:99928431bb44

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MM2WayRanging/MM2WayRanging.h	Tue Jul 07 09:36:12 2015 +0000
@@ -0,0 +1,94 @@
+// by Matthias Grob & Manuel Stalder - ETH Zürich - 2015
+
+#ifndef MM2WAYRANGING_H
+#define MM2WAYRANGING_H
+
+#include "mbed.h"
+#include "DW1000.h"
+
+#define TIMEUNITS_TO_US       (1/(128*499.2))               // conversion between the decawave timeunits (ca 15.65ps) to microseconds.
+#define US_TO_TIMEUNITS       (128*499.2)                   // conversion between microseconds to the decawave timeunits (ca 15.65ps).
+#define MMRANGING_2POWER40          1099511627776               // decimal value of 2^40 to correct timeroverflow between timestamps
+
+
+
+//Predefined delay for the critical answers in the ranging algorithm
+//HAS TO BE BIGGER THAN THE PROCESSING TIME OF THE FRAME ON THE NODE
+#define ANSWER_DELAY_US             2500                                    //2500 works for 110kbps, 900 for 6.8Mbps
+#define ANSWER_DELAY_TIMEUNITS      ANSWER_DELAY_US * (128*499.2)
+
+class MM2WayRanging {
+
+public:
+    MM2WayRanging(DW1000& DW);
+
+    void requestRanging(uint8_t destination);
+    void requestRangingAll();
+
+
+
+    //TODO: Better capsulation on those?
+    uint8_t address; // Identifies the nodes as source and destination in rangingframes
+
+    //TODO: Make those PRIVATE!
+    float roundtriptimes[10]; // Array containing the round trip times to the anchors or the timeout which occured
+    float distances[10]; // Array containing the finally calculated Distances to the anchors
+
+    bool overflow;              // TRUE if counter overflows while ranging
+
+private:
+
+
+    DW1000& dw;
+    Timer LocalTimer;
+
+    void callbackRX();
+    void callbackTX();
+    void sendPingFrame(uint8_t destination);
+    void sendDelayedAnswer(uint8_t destination, uint8_t type, uint64_t rxTimestamp);
+    void sendTransferFrame(uint8_t destination, int timestamp);
+
+    inline float calibratedDistance(uint8_t destination);
+
+    /**
+     * These two functions correct the timestamps if the counter had an overflow between measurements
+     */
+    void correctReceiverTimestamps(uint8_t source);
+    void correctSenderTimestamps(uint8_t source);
+
+    int timediffRec;
+    int timediffSend;
+
+    enum FrameType{
+        PING=1,
+        ANCHOR_RESPONSE,
+        BEACON_RESPONSE,
+        TRANSFER_FRAME,
+        DISTANCES_FRAME
+    };
+
+    //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
+    //IT IS A GCC SPECIFIC DIRECTIVE
+    struct __attribute__((packed, aligned(1))) RangingFrame {
+        uint8_t source;
+        uint8_t destination;
+        uint8_t type;
+    };
+
+    struct __attribute__((packed, aligned(1))) ExtendedRangingFrame : RangingFrame{
+        int signedTime;
+    };
+
+
+    RangingFrame rangingFrame;                  // buffer in class for sending a frame (not made locally because then we can recall in the interrupt what was sent)
+    ExtendedRangingFrame transferFrame;
+    ExtendedRangingFrame receivedFrame;
+    uint64_t rxTimestamp;
+    uint64_t senderTimestamps[10][3];
+    uint64_t receiverTimestamps[10][3];
+    bool acknowledgement[10];                   // flag to indicate if ranging has succeeded
+    uint32_t tofs[10];                          // Array containing time of flights for each node (index is address of node)
+
+};
+
+#endif