Data Received from GPS Devices
The HEX data is exactly what your device sends, without any modifications.
So what about the Info (Time, Latitude, longitude, etc)? Is this decoded by the HEX data or is it retrieved from the devices directly.
Here is a sample from my tracker-server log file:
2017-02-17 00:00:00 DEBUG: [8AF16371: 5082 < XXX.XXX.XXX.XXX] HEX: 83054731011517010101024747582332b4581b1a3af35c578fa0c426c5000005f5000002c7002603340001ff9d065c010c021e0000 2017-02-17 00:00:00 DEBUG: [8AF16371: 5082 > XXX.XXX.XXX.XXX] HEX: 02014747020000000000 2017-02-17 00:00:00 INFO: [8AF16371] id: 4731011520, time: 2017-02-16 18:47:22, lat: -21.20487, lon: -159.80039, speed: 3.4, course: 241.0
So I just wanted to know if traccar is decoding the hex code to get the info or is the info(Lon, lat, time) sent from the device.
The issue I'm having is troubleshooting one of my devices which seem to be bouncing around the map when its parked just outside. So I wasn't sure if its actually the device thats faulty or if something is up with Traccar. Going through the log file the data lon and lat is constantly changing. I used the Hex Decoder https://www.traccar.org/hex-decoder/ to check but when I use the Hex Decoder I just get a bunch of weird characters.
Obviously coordinates and time are decoded from that HEX data. The issue can be either device or server. You can't use HEX decoder because your protocol is binary.
If the issue is my server, are you able to give any guidance to solve this. I have about 10 devices and 3 of them are giving coordinates that are not accurate. The other devices are working fine though. So im assuming its the devices thats faulty but would be great to know for sure that it is the devices thats faulty and not the server.
If other devices with the same protocol work fine, then yes, it's very likely that the problem is on the device side.
I can take a look if you provide HEX messages samples corresponding to those "bounces" on the map.
The other devices do use same protocol. One device of the 3 faulty ones I am positively sure the device is faulty as its just sitting on the reef..lol.
Below is sample from the day I monitored a vehicle(id:4731011518) that was parked. I constantly received notifications (every couple minutes or so) that it was entering and exiting a geofence starting a day before this sample so started monitoring it this day and saw that it was bouncing around on traccar.
see below:
2017-01-31 14:46:10 DEBUG: [8AF16371: 5082 < XXX.XXX.XXX.XXX] HEX: 83054731011518010101029c2358912ee858912ee8f35bd48ba0c3e1800000090600000032007706000001ffb90f130300061f0000 2017-01-31 14:46:10 DEBUG: [8AF16371: 5082 > XXX.XXX.XXX.XXX] HEX: 02019c23020000000000 2017-01-31 14:46:11 INFO: [8AF16371] id: 4731011518, time: 2017-01-31 14:42:16, lat: -21.20856, lon: -159.77755, speed: 1.0, course: 119.0 ... 2017-01-31 14:48:55 DEBUG: [8AF16371: 5082 < XXX.XXX.XXX.XXX] HEX: 83054731011518010101029c2358912ee858912ee8f35bd48ba0c3e1800000090600000032007706200001ffb90f130300061f0000 2017-01-31 14:48:55 DEBUG: [8AF16371: 5082 > XXX.XXX.XXX.XXX] HEX: 02019c23020000000000 2017-01-31 14:48:55 INFO: [8AF16371] id: 4731011518, time: 2017-01-31 14:42:16, lat: -21.20856, lon: -159.77755, speed: 1.0, course: 119.0 ... 2017-01-31 14:51:45 DEBUG: [8AF16371: 5082 < XXX.XXX.XXX.XXX] HEX: 83054731011518010101029c2358912ee858912ee8f35bd48ba0c3e1800000090600000032007706200001ffb90f130300061f0000 2017-01-31 14:51:45 DEBUG: [8AF16371: 5082 > XXX.XXX.XXX.XXX] HEX: 02019c23020000000000 2017-01-31 14:51:45 INFO: [8AF16371] id: 4731011518, time: 2017-01-31 14:42:16, lat: -21.20856, lon: -159.77755, speed: 1.0, course: 119.0 2017-01-31 14:51:45 DEBUG: [8AF16371: 5082 < XXX.XXX.XXX.XXX] HEX: 83054731011518010101029c2458912ef158912ef1f35bd6eda0c3dfcd000000000000003d012a06200001ffb90f170100021e0000 2017-01-31 14:51:45 DEBUG: [8AF16371: 5082 > XXX.XXX.XXX.XXX] HEX: 02019c24020000000000 2017-01-31 14:51:46 INFO: [8AF16371] id: 4731011518, time: 2017-01-31 14:42:25, lat: -21.20850, lon: -159.77759, speed: 1.2, course: 298.0 ... 2017-01-31 14:54:15 DEBUG: [8AF16371: 5082 < XXX.XXX.XXX.XXX] HEX: 83054731011518010101029c2558912efb58912efbf35bd5dfa0c3e0d30000000b00000029012105200001ffb90f120100021e0000 2017-01-31 14:54:15 DEBUG: [8AF16371: 5082 > XXX.XXX.XXX.XXX] HEX: 02019c25020000000000 2017-01-31 14:54:15 INFO: [8AF16371] id: 4731011518, time: 2017-01-31 14:42:35, lat: -21.20853, lon: -159.77757, speed: 0.8, course: 289.0 ... 2017-01-31 14:57:31 DEBUG: [8AF16371: 5082 < XXX.XXX.XXX.XXX] HEX: 83054731011518010101029c2558912efb58912efbf35bd5dfa0c3e0d30000000b00000029012105200001ffb90f120100021e0000 2017-01-31 14:57:31 DEBUG: [8AF16371: 5082 > XXX.XXX.XXX.XXX] HEX: 02019c25020000000000 2017-01-31 14:57:31 INFO: [8AF16371] id: 4731011518, time: 2017-01-31 14:42:35, lat: -21.20853, lon: -159.77757, speed: 0.8, course: 289.0 ... 2017-01-31 15:00:03 DEBUG: [8AF16371: 5082 < XXX.XXX.XXX.XXX] HEX: 83054731011518010101029c2558912efb58912efbf35bd5dfa0c3e0d30000000b00000029012105200001ffb90f120100021e0000 2017-01-31 15:00:03 DEBUG: [8AF16371: 5082 > XXX.XXX.XXX.XXX] HEX: 02019c25020000000000 2017-01-31 15:00:04 INFO: [8AF16371] id: 4731011518, time: 2017-01-31 14:42:35, lat: -21.20853, lon: -159.77757, speed: 0.8, course: 289.0 2017-01-31 15:00:04 DEBUG: [8AF16371: 5082 < XXX.XXX.XXX.XXX] HEX: 83054731011518010101029c2658912f0558912f05f35bd371a0c3dfed0000011400000013010706200001ffb90f0c0300021e0000 2017-01-31 15:00:04 DEBUG: [8AF16371: 5082 > XXX.XXX.XXX.XXX] HEX: 02019c26020000000000 2017-01-31 15:00:05 INFO: [8AF16371] id: 4731011518, time: 2017-01-31 14:42:45, lat: -21.20859, lon: -159.77759, speed: 0.4, course: 263.0 2017-01-31 15:00:05 DEBUG: [8AF16371: 5082 < XXX.XXX.XXX.XXX] HEX: 83054731011518010101029c2758912f0f58912f0ff35bd41ba0c3e205000001ab0000007d000905200001ffb90f2f0100021e0000 2017-01-31 15:00:05 DEBUG: [8AF16371: 5082 > XXX.XXX.XXX.XXX] HEX: 02019c27020000000000 2017-01-31 15:00:06 INFO: [8AF16371] id: 4731011518, time: 2017-01-31 14:42:55, lat: -21.20857, lon: -159.77754, speed: 2.4, course: 9.0 2017-01-31 15:00:06 DEBUG: [8AF16371: 5082 < XXX.XXX.XXX.XXX] HEX: 83054731011518010101029c2858912f1458912f14f35bd44ba0c3df7b00000000000000af014a04200001ffb90f14000007200000 2017-01-31 15:00:06 DEBUG: [8AF16371: 5082 > XXX.XXX.XXX.XXX] HEX: 02019c28020000000000 2017-01-31 15:00:07 INFO: [8AF16371] id: 4731011518, time: 2017-01-31 14:43:00, lat: -21.20857, lon: -159.77760, speed: 3.4, course: 330.0 ...
I have filtered data for 4731011518. Please don't post massive log file fragments directly into the forum. Either pick relevant data, or upload the log file somewhere and give a link in the post.
Anyway, I see that the difference between positions is less than 10 meters, which is within GPS error. Is that the "bouncing" you were talking about? If yes, that's normal GPS behaviour. Error can be up to 30 meters, or even more with reflected satellite signal.
Apologies,
Yes that is the bouncing I was talking about. There has been cases where it kept entering and exiting a geofence which was about 25-30 meters away. The device has been fine the past couple days though but just thought I investigate this issue.
Anyways thanks for clearing that up. Very much appreciated. Great stuff
Also note that GPS only works outdoors with clear sky visibility. If your vehicle is under a cover (e.g. garage) or next to a tall building, you will be getting reflected signal and error can easily be 100 meters or even more. That's just how GPS system works.
I would like to know if the data in the log files is exactly what the devices in the vehicles send to my Traccar Server. Or does Traccar translate the data/HEX code before storing to the log files??