4.5 KiB
4.5 KiB
AT Commands User Guide
This document provides detailed usage instructions for the main AT commands supported by the H11 device.
1. AT+DEV_INIT_STA=GET
Function: Query device initialization status
Command Format:
AT+DEV_INIT_STA=GET
Response Example:
AT+DEV_INIT_STA=GET,4G,<4G_link>,<SIM_ready>,<NTRIP_flag>,<CSQ>,<data_back>,<upload_size>,<NTRIP_size>,GNSS,<status>,<reserved>,star,<SNR45>,<SNR48>,<SNR50>,<visible_stars>
OK
Parameter Explanation:
<4G_link>: 4G network connection status (0=disconnected, 1=connected)<SIM_ready>: SIM card ready status (0=not ready, 1=ready)<NTRIP_flag>: NTRIP connection status (0=disconnected, 1=connected)<CSQ>: Signal quality (0-31, higher is better)<data_back>: Data upload status (0=idle, 1=uploading)<upload_size>: Upload queue size (bytes)<NTRIP_size>: NTRIP data queue size (bytes)<status>: GNSS module status<SNR45>,<SNR48>,<SNR50>: Number of satellites with SNR > 45/48/50 dB<visible_stars>: Total number of visible satellites
Use Cases:
- Check device module initialization status after startup
- Diagnose device connectivity and module status
- Monitor network and GNSS module status
2. AT+NEMATIME=SET
Function: Set NMEA output frequency
Command Format:
AT+NEMATIME=SET,<frequency>
Parameters:
<frequency>: Output frequency in Hz (supported values: 1, 2, 5, 10)
Response Example:
AT+NEMATIME=SET
OK
Error Response:
AT+NEMATIME=SET
ERROR
Use Cases:
- Configure GNSS position data output rate
- Adjust positioning data update frequency based on application requirements
- Balance between update rate and power consumption
3. AT+NEMATIME=GET
Function: Query current NMEA output frequency
Command Format:
AT+NEMATIME=GET
Response Example:
AT+NEMATIME=GET,<frequency>
OK
Parameter Explanation:
<frequency>: Current NMEA output frequency in Hz
Use Cases:
- Verify the current NMEA output frequency configuration
- Ensure frequency configuration has taken effect
- Troubleshoot positioning data update issues
4. AT+RTCMBASEPOS=GET
Function: Query base station position and distance from RTCM data source
Command Format:
AT+RTCMBASEPOS=GET
Response Example (when RTCM data is available):
AT+RTCMBASEPOS=GET,<latitude>,<longitude>,<altitude>,<distance>
OK
Response Example (when RTCM data is not available):
AT+RTCMBASEPOS=GET,0.0,0.0,0.0,0.0
OK
Parameter Explanation:
<latitude>: Base station latitude in degrees (positive=North, negative=South)<longitude>: Base station longitude in degrees (positive=East, negative=West)<altitude>: Base station altitude/elevation in meters<distance>: Distance from device to base station in meters
Use Cases:
- Obtain current base station position information in RTK mode
- Monitor distance to reference station
- Assess differential positioning quality
- Verify RTK connection status
Command Usage Examples
Query device initialization status
→ AT+DEV_INIT_STA=GET
← AT+DEV_INIT_STA=GET,4G,1,1,1,25,0,0,1024,GNSS,1,0,star,8,5,2,12
← OK
Set NMEA frequency to 1Hz
→ AT+NEMATIME=SET,1
← AT+NEMATIME=SET
← OK
Query current NMEA frequency
→ AT+NEMATIME=GET
← AT+NEMATIME=GET,1
← OK
Query base station position and distance
→ AT+RTCMBASEPOS=GET
← AT+RTCMBASEPOS=GET,31.135370,121.287729,22.467,1234.56
← OK
Important Notes
- Command Format: All AT commands start with "AT" and end with "\r\n"
- Case Insensitive: Commands are case-insensitive
- Response Timeout: Recommended timeout for each command is 5 seconds
- Response Format: Successful execution returns "OK", failure returns "ERROR"
- RTCM Base Station Info: Base station position is only available after receiving valid RTCM 1005/1006 messages
- Frequency Setting: Device may need restart for frequency changes to take effect
- Line Ending: Use CR+LF (\r\n) as line terminator
- Serial Parameters: Default baud rate is 115200 bps
Related Information
- NMEA: National Marine Electronics Association protocol, widely used in GPS/GNSS devices
- RTCM: Radio Technical Commission for Maritime Services, data format for differential positioning
- RTK: Real-Time Kinematic positioning technology
- CSQ: Signal Quality indicator (0-31, where 31 is excellent)
- SNR: Signal-to-Noise Ratio measured in dB