ardupilot/libraries/AP_Scripting/examples/trisonicia-mini.md

Trisonica LI-550 Mini Wind Sensor Logger

This Lua script reads and logs wind sensor data from the Trisonica LI-550 Mini ultrasonic wind sensor connected via serial. It decodes ASCII-formatted key-value pairs and logs the data using dynamic field tags on the W3D logging stream.

For sensor details, visit: 🔗 LI-COR

Features

• Parses and logs ASCII data strings from the Trisonica LI-550 Mini in BIN logs
• Logs fields using a dynamically generated tag list from the first packet
• Ignores extraneous fields in subsequent messages not present in the first
• Compatible with ArduPilot scripting serial port interface
• Supports high-speed 230400 baud data stream
• Uses BIN log name W3D for all data

Parameters

Set the following parameters:

Parameter	Value	Description
SCR_ENABLE	1	Enable Lua scripting
SERIALx_PROTOCOL	28	Scripting protocol for SERIALx

Replace SERIALx with the appropriate serial port used on your hardware.

Sensor configuration

Use Trisonica's CLI to configure the unit. On Linux, you can use screen to interract with the device:

screen /dev/ttyUSB0 230400

You should see data displayed. Enter configuration mode with Ctrl+C. You should now see data streaming stop and a terminal prompt >.

Set the Trisonica sensor baudrate to 230400 in its configuration software using the baudrate command like so:

baudrate 230400

You must also enable all fields you want to log. A recommended set is as follows. See the Enabled column.

display

-----------------------------------------------------------------------------------------
|     Name |            Description |  Tagged |      Tag | Decimals | Enabled |  Units  |
-----------------------------------------------------------------------------------------
|    IDTag |                 ID Tag |   Yes   |          |          |         |         |
|        S |          Wind Speed 3D |   Yes   |        S |     2    |         | m/s     |
|      S2D |          Wind Speed 2D |   Yes   |       S2 |     2    |         | m/s     |
|        D |   Horiz Wind Direction |   Yes   |        D |     0    |         | Degrees |
|       DV |    Vert Wind Direction |   Yes   |       DV |     0    |         | Degrees |
|        U |               U Vector |   Yes   |        U |     2    |   Yes   | m/s     |
|        V |               V Vector |   Yes   |        V |     2    |   Yes   | m/s     |
|        W |               W Vector |   Yes   |        W |     2    |   Yes   | m/s     |
|        T |            Temperature |   Yes   |        T |     2    |   Yes   | C       |
|       Cs |         Speed of Sound |   Yes   |        C |     2    |         | m/s     |
|   RHTemp |         RH Temp Sensor |   Yes   |     RHST |     2    |         | C       |
|       RH |     RH Humidity Sensor |   Yes   |     RHSH |     2    |         | %       |
|        H |               Humidity |   Yes   |        H |     2    |   Yes   | %       |
|       DP |               DewPoint |   Yes   |       DP |     2    |         | C       |
|    PTemp |   Pressure Temp Sensor |   Yes   |      PST |     2    |         | C       |
|        P |        Pressure Sensor |   Yes   |        P |          |   Yes   | hPa     |
|  Density |            Air Density |   Yes   |       AD |          |   Yes   | kg/m^3  |
|   LevelX |                Level X |   Yes   |       AX |          |   Yes   |         |
|   LevelY |                Level Y |   Yes   |       AY |          |   Yes   |         |
|   LevelZ |                Level Z |   Yes   |       AZ |          |   Yes   |         |
|    Pitch |                  Pitch |   Yes   |       PI |     1    |   Yes   | Degrees |
|     Roll |                   Roll |   Yes   |       RO |     1    |   Yes   | Degrees |
|    CTemp |           Compass Temp |   Yes   |       MT |     1    |         | C       |
|     MagX |              Compass X |   Yes   |       MX |          |         |         |
|     MagY |              Compass Y |   Yes   |       MY |          |         |         |
|     MagZ |              Compass Z |   Yes   |       MZ |          |         |         |
|  Heading |        Compass Heading |   Yes   |       MD |     0    |   Yes   | Degrees |
| TrueHead |           True Heading |   Yes   |       TD |     0    |   Yes   | Degrees |
-----------------------------------------------------------------------------------------

You can enable tags like so:

show T

Or disable them from the data stream like so:

hide T

You must not enable more than 12 outputs due to limitations in this script and ArduPilot's dataflash logger.

Finally, increase the output rate to the maximum of 10 Hz.

outputrate 10

Once configuration is complete, exit screen with

ctr+A k y

If you take longer than a minute to configure, the unit will re-enter streaming mode.

SITL Testing

You can connect a real serial device to SITL using a passthrough UART setup. For example, using SERIAL5 connected to ttyUSB0.

./Tools/autotest/sim_vehicle.py -v Plane --console --map -A "--serial5=uart:/dev/ttyUSB0" -D

Then view the W3D entries in your favorite dataflash (BIN) log analyzer. For MAVExplorer, try graphing wind speeds against airspeed.

graph W3D.U W3D.W W3D.V ARSP.Airspeed

Future Improvements

• Use the wind data as input to the EKF for wind speed
• Use the Trisonica API to have ArduPilot configure the correct data outputs and rates