¶ Description
Hardware communication module with Wi-Fi and Bluetooth, connected to GPS trackers via RS-232 or RS-485 to extend device functionality.
The SIGMA module is supplied with a universal base firmware
AT-MODEM. This firmware allows control of the module using AT commands and enables the implementation of various functions:
- scanning Wi-Fi networks and Bluetooth devices;
- connecting to various Wi-Fi access points for data exchange;
- operating as an access point for other Wi-Fi devices;
- reading the input line status;
- controlling the output line.
When operating with
AT-MODEMfirmware, the SIGMA module is not a standalone device.
Its operating mode is defined by the navigation terminal or any other controlling device by sending the required AT commands.
¶ Connection diagram
Click Show to view the connection diagram
To view the diagram in high resolution, open the image in a new tab or download the PDF file
¶ Documentation
Equipment datasheet
AT-MODEM protocol description Article with full protocol description and examples
Connection guidelines
¶ Firmware
| Firmware | Description |
|---|---|
| v01.00.15 dated 04.03.2026 | - Increased UART buffer size for output of packets received via TCP/UDP |
| v01.00.14 dated 25.02.2026 | - Changed MAC address output format |
| v01.00.13 dated 19.02.2026 | - Minimum packet size for TCP/UDP transmission increased to 1440 bytes; - Improved security of the AT+WRITEB command |