SDM18 and RDK Communication

SDM18 Introduction

• The YDLIDAR SDM18 LiDAR (hereafter referred to as the SDM18) is a high-performance single-point LiDAR. This product utilizes the time-of-flight ranging principle and incorporates relevant optical, electrical, and algorithmic design to achieve high-precision laser distance measurement and output point cloud data at a high frame rate.

• Product Features ➢ High ranging frequency, internal high sampling rate combined with filtering algorithms, resulting in highly stable data. ➢ Long detection range, up to 18 meters. ➢ Lightweight, approximately 1.35g. ➢ Laser power meets FDA Class I safety standards.

1. Experimental Preparation

• SDM18 Laser Ranging Module

• RDKSeries This tutorial uses the RDK X5 and RDK X3 is also applicable.

2. Experimental Wiring

Note: You can solder the pin headers to the serial port adapter board yourself. The default pin headers are not included. For our testing, we cannot use pin-based communication, so we need to use a USB port. Here, we directly connect the motherboard and SDM18 via Type-C (UART baud rate 921600).

The wiring diagram is shown in the figure.

3. Experimental Steps

1. Install the sdm18_test.py program provided in the example program into the Jetson.

2. After connecting the USB, type lsusb. If the following device is recognized, the connection is successful.

3. Run ls /dev/ttyUSB* to see if the USB device is recognized. If it is, skip step 4. If not, proceed to step 4.

   The following takes the installation of drivers on jetson as an example. RDK can be run directly using our image, and the following steps can be ignored

4. Enter lsusb -t in terminal

git clone https://github.com/juliagoda/CH341SER.git cd CH341SER make -j6 sudo make install sudo modprobe ch34x

Then enter modinfo ch34x in terminal

If successful, the following information will be displayed.

You can first execute the following command to see if a device such as 'ttyUSB*' appears. If successful, continue with the following steps. If