Hongke Case | Car Steering Wheel HOD Function Test Based on Baby-LIN-RM-III

Application Background

The steering wheel module of a new energy vehicle adopts LIN bus communication, and the module contains touch function. LIN bus communication detects touch action through the main controller (i.e., main node).

Finally, the HOD function test of the steering wheel module is realized.

Products Used

Product model: Babylin-RM-III

Main function: Use Babylin-RM-III to simulate the LIN master node to control the touch action detection. In addition, use the Digital Output of Babylin-RM-III to output the status of each touch operation, and finally run offline without the host computer software.

Application methods and processes

The hardware is connected according to the pin wiring diagram of the corresponding device. The line connection diagram is shown in the figure below;

Use software to configure the communication matrix or LDF/DBC file into an SDF file;

First, set the HOD signal, HOD touch function with no touch, one-hand grip and two-hand grip;

Secondly, the detection of touch status is distributed. The combination form of the 2-way Digital Output of Babylin-RM-III is used, that is, up to 4 combinations. Each touch operation corresponds to a combination output, and the Digital Output detects the operation state of each touch.

After writing the configured SDF into Baby-LIN-RM-III, you can start the communication by powering off Baby-LIN or giving input from the host computer such as PLC, and test the HOD touch function by detecting the output signal.

Hardware Hookup Sketch

result

After Baby-LIN is powered on and restarted or PLC gives a rising edge level jump, the schedule table will be run;

Touch status, PLC detects each operation status by monitoring the output signal.

Multi-function steering wheel actual measurement picture

Correspondence between steering wheel HOD function detection and Babylin-DOUT output (partial)