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Diffstat (limited to 'src/main/java/org/traccar/protocol/Mavlink2ProtocolDecoder.java')
-rw-r--r--src/main/java/org/traccar/protocol/Mavlink2ProtocolDecoder.java128
1 files changed, 128 insertions, 0 deletions
diff --git a/src/main/java/org/traccar/protocol/Mavlink2ProtocolDecoder.java b/src/main/java/org/traccar/protocol/Mavlink2ProtocolDecoder.java
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index 000000000..d23398bce
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+++ b/src/main/java/org/traccar/protocol/Mavlink2ProtocolDecoder.java
@@ -0,0 +1,128 @@
+package org.traccar.protocol;
+
+import java.net.SocketAddress;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.time.Instant;
+import java.util.Arrays;
+import java.util.Date;
+
+import org.traccar.BaseProtocolDecoder;
+import org.traccar.DeviceSession;
+import org.traccar.Protocol;
+import org.traccar.model.Position;
+
+import io.netty.channel.Channel;
+
+public class Mavlink2ProtocolDecoder extends BaseProtocolDecoder {
+
+ public Mavlink2ProtocolDecoder(Protocol protocol) {
+ super(protocol);
+ }
+
+ @Override
+ protected Object decode(Channel channel, SocketAddress remoteAddress, Object pkt) throws Exception {
+ byte[] packet = (byte[]) pkt;
+ /*
+ * 0 uint8_t magic Packet start marker 0xFD Protocol-specific start-of-text
+ * (STX) marker used to indicate the beginning of a new packet. Any system that
+ * does not understand protocol version will skip the packet.
+ * *
+ * 1 uint8_t len Payload length 0 - 255 Indicates length of the following
+ * payload section. This may be affected by payload truncation.
+ * *
+ * 2 uint8_t incompat_flags Incompatibility Flags Flags that must be understood
+ * for MAVLink compatibility (implementation discards packet if it does not
+ * understand flag).
+ * *
+ * 3 uint8_t compat_flags Compatibility Flags Flags that can be ignored if not
+ * understood (implementation can still handle packet even if it does not
+ * understand flag).
+ * *
+ * 4 uint8_t seq Packet sequence number 0 - 255 Used to detect packet loss.
+ * Components increment value for each message sent.
+ * *
+ * 5 uint8_t sysid System ID (sender) 1 - 255 ID of system (vehicle) sending the
+ * message. Used to differentiate systems on network. Note that the broadcast
+ * address 0 may not be used in this field as it is an invalid source address.
+ * *
+ * 6 uint8_t compid Component ID (sender) 1 - 255 ID of component sending the
+ * message. Used to differentiate components in a system (e.g. autopilot and a
+ * camera). Use appropriate values in MAV_COMPONENT. Note that the broadcast
+ * address MAV_COMP_ID_ALL may not be used in this field as it is an invalid
+ * source address.
+ * *
+ * 7 to 9 uint32_t msgid:24 Message ID (low, middle, high bytes) 0 - 16777215 ID
+ * of message type in payload. Used to decode data back into message object.
+ * *
+ * 10 to (n+10) uint8_t payload[max 255] Payload Message data. Depends on
+ * message type (i.e. Message ID) and contents.
+ * *
+ * (n+10) to (n+11) uint16_t checksum Checksum (low byte, high byte)
+ * CRC-16/MCRF4XX for message (excluding magic byte). Includes CRC_EXTRA byte.
+ * *
+ * (n+12) to (n+25) uint8_t signature[13] Signature (Optional) Signature to
+ * ensure the link is tamper-proof.
+ */
+
+ if (packet[0] != (byte) 0xfd) {
+ return null;
+ }
+
+ int msgid = (packet[7] & 0xff) | ((packet[8] & 0xff) << 8) | ((packet[9] & 0x0f) << 16);
+ int len = packet[1] & 0xff;
+ int sysid = packet[5] & 0xff;
+ // GLOBAL_POSITION_INT ( #33 )
+ if (msgid == 33) {
+ byte[] message = Arrays.copyOfRange(packet, 10, 10 + len);
+ /*
+ * time_boot_ms uint32_t ms Timestamp (time since system boot).
+ * *
+ * lat int32_t degE7 Latitude, expressed
+ * *
+ * lon int32_t degE7 Longitude, expressed
+ * *
+ * alt int32_t mm Altitude (MSL). Note that virtually all GPS modules provide
+ * both WGS84 and MSL.
+ * *
+ * relative_alt int32_t mm Altitude above ground
+ * *
+ * vx int16_t cm/s Ground X Speed (Latitude, positive north)
+ * *
+ * vy int16_t cm/s Ground Y Speed (Longitude, positive east)
+ * *
+ * vz int16_t cm/s Ground Z Speed (Altitude, positive down)
+ * *
+ * hdg uint16_t cdeg Vehicle heading (yaw angle), 0.0..359.99 degrees. If
+ * unknown, set to: UINT16_MAX
+ */
+
+ // int timeBootms = ByteBuffer.wrap(message, 0, 4).order(ByteOrder.LITTLE_ENDIAN).getInt();
+ int lat = ByteBuffer.wrap(message, 4, 4).order(ByteOrder.LITTLE_ENDIAN).getInt();
+ int lon = ByteBuffer.wrap(message, 8, 4).order(ByteOrder.LITTLE_ENDIAN).getInt();
+ int alt = ByteBuffer.wrap(message, 12, 4).order(ByteOrder.LITTLE_ENDIAN).getInt();
+ int vx = ByteBuffer.wrap(message, 20, 2).order(ByteOrder.LITTLE_ENDIAN).getShort();
+ int vy = ByteBuffer.wrap(message, 22, 2).order(ByteOrder.LITTLE_ENDIAN).getShort();
+ int hdg = ByteBuffer.wrap(message, 26, 2).order(ByteOrder.LITTLE_ENDIAN).getShort();
+ DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, Integer.toString(sysid));
+ if (deviceSession == null) {
+ return null;
+ }
+ Position position = new Position(getProtocolName());
+ position.setDeviceId(deviceSession.getDeviceId());
+ position.setValid(true);
+ // position.setTime(Date.from(Instant.ofEpochMilli(timeBootms)));
+ position.setTime(Date.from(Instant.now()));
+ position.setLatitude(lat / 1e7);
+ position.setLongitude(lon / 1e7);
+ position.setAltitude(alt / 1e3);
+ double speed = Math.sqrt(Math.pow(vx, 2) + Math.pow(vy, 2));
+ // cm/s to kn
+ position.setSpeed(speed * 0.01943844);
+ position.setCourse(hdg / 1e2);
+ return position;
+ }
+ return null;
+ }
+
+}