Door lock and unlock 5G
Hello,
Have you found your device? I am looking for the same things (and possibily with fuel monitoring)
MiCODUS MV750G are have this function !
Perfect ! Thank you! It is exactly what I need and it is cheap on AliExpress. I hope it is compatible with traccar.
I will now just need a way to follow fuel tank remotely.
Hi! The MiCODUS MV750G is not fully compatible with Traccar because it uses a customized JT808 protocol. To register the device, you must use the Serial Number but you need to add a "0" (zero) as a prefix.
Commands are also incompatible for the same reason (the requirement of the leading zero in the serial number). The best solution is to create a Python proxy so Traccar can send commands to the devices without having to modify the source code.
Have you verified it against the latest code?
Hi Anton! Thanks for reaching out!
Yes, I tested it against the latest Traccar version. Here's what I found after doing a deep dive into the protocol:
The MiCODUS MV750G uses a customized JT808 protocol where the engineStop/engineResume commands don't work with the standard 0x8105 message that Traccar generates (with payload 0xF0/0xF1). The device actually expects a 0x8500 message with payload 0x01 (cut off) or 0x00 (restore).
I noticed that the Jt808ProtocolEncoder already has an 'alternative' mode that uses MSG_OIL_CONTROL (0x8500), which is exactly the right message ID. However, the alternative mode also appends a timestamp (yyMMddHHmmss) after the action byte, and the MiCODUS device seems to reject or ignore the command when that extra data is present. The working payload is simply 0x01 or 0x00, nothing else.
The device also supports door lock/unlock via 0x8103 with specific parameters:
- Unlock door: payload 010000FF3103010001
- Lock door: payload 010000FF320401010000
These are the exact payloads captured directly from the official MiCODUS server using a proxy sniffer, so they are confirmed working.
Since we wanted to avoid modifying Traccar's source code, we built a Python proxy that sits between the device and Traccar. It intercepts the 0x8105 commands and rewrites them as proper 0x8500 commands before forwarding to the device. It works reliably across multiple simultaneous devices.
For the device ID issue: the MiCODUS serial number is 11 digits, but Traccar requires 12, so adding a leading zero makes it register correctly. The device itself sends its ID as 11 digits in the JT808 frames, so there's no mismatch on the data side — only on the command side when Traccar builds the outgoing frame using the stored 12-digit ID.
Would it be feasible to add a MiCODUS-specific variant in the JT808 encoder that sends 0x8500 with just the single action byte, and also support the door lock/unlock commands via 0x8103?
Hello, I am looking for a device that can lock and unlock car doors in addition to get GPS data. It must not be 3G which is the ones I can find. Any recommendations?