diff options
Diffstat (limited to 'src/main/java/org/traccar/protocol/Mavlink2ProtocolDecoder.java')
| -rw-r--r-- | src/main/java/org/traccar/protocol/Mavlink2ProtocolDecoder.java | 128 |
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 new file mode 100644 index 000000000..d23398bce --- /dev/null +++ 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; + } + +} |