mavproxy_locdb.py: add a module to fetch locationdb items

MAVProxy/modules/mavproxy_locdb.py

@@ -0,0 +1,197 @@
+#!/usr/bin/env python
+'''locationdb command handling'''
+
+import struct
+from pymavlink import mavutil
+from MAVProxy.modules.lib import mp_module
+from MAVProxy.modules.lib import mp_util
+
+if mp_util.has_wxpython:
+    from MAVProxy.modules.lib import mp_menu
+    from MAVProxy.modules.mavproxy_map import mp_slipmap
+
+
+class DBItem():
+    def __init__(self):
+        self.key = 0
+        self.timestamp_ms = 0
+        self.lat = 0
+        self.lon = 0
+        self.alt = 0
+        self.velx = 0
+        self.vely = 0
+        self.velz = 0
+        self.accx = 0
+        self.accy = 0
+        self.accz = 0
+        self.heading = 0
+        self.radius = 0
+        self.populated_fields = 0
+        self.onMap = False
+
+
+class LocDBModule(mp_module.MPModule):
+    def __init__(self, mpstate):
+        super(LocDBModule, self).__init__(mpstate, "locdb", "LocationDB handling", public=True)
+        self.add_command('locdb', self.cmd_locdb, 'locationdb management',
+                         ["<list>"])
+        self.locdb_ftp_name = "@LOCATIONDB/locationdb.dat"
+        self.num_items = 0
+        self.background_fetch = True
+        self.item_refresh_timer = mavutil.periodic_event(0.5)
+        self.dbitems = []
+
+    def cmd_locdb(self, args):
+        '''locationdb commands'''
+        usage = "usage: locdb <list>"
+        if len(args) < 1:
+            print(usage)
+            return
+
+        if args[0] == "list":
+            self.background_fetch = False
+            self.dbitems_list()
+        else:
+            print(usage)
+
+    def dbitems_list(self):
+        print("Total DB Items: %u" % self.num_items)
+        for item in self.dbitems:
+            print("Key:%s, Last Update:%u, Lat:%.2f, Lon:%.2f, Alt:%.2f , Vel:(%.2f, %.2f, %.2f), Acc:(%.2f, %.2f, %.2f), Hdg:%.2f, Rad:%.2f" % ( # noqa
+                item.key,
+                item.timestamp_ms,
+                item.lat,
+                item.lon,
+                item.alt,
+                item.velx,
+                item.vely,
+                item.velz,
+                item.accx,
+                item.accy,
+                item.accz,
+                item.heading,
+                item.radius
+            ))
+        return
+
+    def update_map(self, new_items):
+        for mp in self.module_matching('map*'):
+            # remove all old items
+            for item in self.dbitems:
+                if item.onMap:
+                    mp.map.remove_object(item.key)
+
+            # show new items
+            for new_item in new_items:
+                if not new_item.onMap:
+                    menu_item = mp_menu.MPMenuItem(
+                        'Follow',
+                        'Follow this object',
+                        '# command_int GLOBAL MAV_CMD_DO_FOLLOW 0 0 0 2 0 0 0 '+str(int(new_item.key, 16))+' 0'
+                    )
+                    popup = mp_menu.MPMenuSubMenu('LOCDB', items=[menu_item])
+                    icon = mp_slipmap.SlipIcon(
+                        new_item.key,
+                        (new_item.lat * 1e-7, new_item.lon * 1e-7),
+                        mp.map.icon('greensinglecopter.png'),
+                        layer=3,
+                        rotation=new_item.heading*0.01,
+                        follow=False,
+                        trail=mp_slipmap.SlipTrail(colour=(0, 255, 255)),
+                        popup_menu=popup
+                    )
+                    mp.map.add_object(icon)
+                    new_item.onMap = True
+
+        # update the item list
+        self.dbitems = new_items
+
+    def create_DBItem_from_packet(self, packet, header_size):
+        '''return DBItem by decoding a packet'''
+        item = DBItem()
+        item.key, item.timestamp_ms, item.populated_fields = (struct.unpack("<IIBB", packet[:header_size]))[:3]
+        item.key = hex(item.key)
+        packet = packet[header_size:]
+
+        # Populated field bitmask:
+        # POS = (1U << 0)
+        # VEL = (1U << 1)
+        # ACC = (1U << 2)
+        # HEADING = (1U << 3)
+        # RADIUS = (1U << 4)
+
+        if (item.populated_fields & (1 << 0)) != 0:
+            pos_info = packet[:12]
+            packet = packet[12:]
+            item.lat, item.lon, item.alt = struct.unpack("<fff", pos_info)
+
+        if (item.populated_fields & (1 << 1)) != 0:
+            vel_info = packet[:12]
+            packet = packet[12:]
+            item.velx, item.vely, item.velz = struct.unpack("<fff", vel_info)
+
+        if (item.populated_fields & (1 << 2)) != 0:
+            acc_info = packet[:12]
+            packet = packet[12:]
+            item.accx, item.accy, item.accz = struct.unpack("<fff", acc_info)
+
+        if (item.populated_fields & (1 << 3)) != 0:
+            heading_info = packet[:4]
+            packet = packet[4:]
+            item.heading = (struct.unpack("<f", heading_info))[0]
+
+        if (item.populated_fields & (1 << 4)) != 0:
+            radius_info = packet[:4]
+            packet = packet[4:]
+            item.radius = (struct.unpack("<f", radius_info))[0]
+
+        if len(packet) > 0:
+            print("locdb: packet size and field bitmask mismatch")
+            return None
+
+        return item
+
+    def ftp_callback(self, fh):
+        '''callback from ftp fetch of db items'''
+        if fh is None:
+            return
+        magic = 0x2801
+        data = fh.read()
+        magic2, num_items = struct.unpack("<HH", data[0:4])
+        self.num_items = num_items
+        if magic != magic2:
+            print("locationdb: bad magic 0x%x expected 0x%x" % (magic2, magic))
+            return
+
+        data = data[4:]
+        packet_header_size = 10
+        items = []
+        while len(data) >= packet_header_size:
+            packed_header = data[:packet_header_size]
+            unpacked_header = struct.unpack("<IIBB", packed_header)
+            filled_fields_count = unpacked_header[3]
+            compressed_packet_size = packet_header_size + 4 * filled_fields_count
+            if len(data) >= compressed_packet_size:
+                packet = data[:compressed_packet_size]
+                data = data[compressed_packet_size:]
+                item = self.create_DBItem_from_packet(packet, packet_header_size)
+                if item is not None:
+                    items.append(item)
+
+        self.update_map(items)
+
+    def update_items(self):
+        ftp = self.mpstate.module('ftp')
+        if ftp is None:
+            return
+        ftp.cmd_get([self.locdb_ftp_name], callback=self.ftp_callback)
+
+    def idle_task(self):
+        '''called on idle'''
+        if self.item_refresh_timer.trigger():
+            self.update_items()
+
+
+def init(mpstate):
+    '''initialise module'''
+    return LocDBModule(mpstate)