PX4-Autopilot: SF11/C Laser Altimeter Missing Documentation

Hello, I’m using SF11/C for distance sensor. I tried to connect SF11/C to Pixhawk 2.1 (Cube) by using https://docs.px4.io/en/sensor/sfxx_lidar.html documentation via serial connection. However, I got no data from SF11/C until change Firmware of SF11/C. Addition, there was a no data in QGroundControl Analyze tool.

SF11/C comes with 115200 baudrate.

But, src/drivers/distance_sensor/sf0x/sf0x.cpp definition has 9600 baud rate. https://github.com/PX4/Firmware/blob/a08b1682e39c2a63c732f9edc10019d55b269498/src/drivers/distance_sensor/sf0x/sf0x.cpp#L593

I tried to change the line 9600 to 115200 and flashed. But, Pixhawk didn’t boot. So, from SF11/C user manual I connected SF11/C directly to PC via micro-USB cable. Default Menu comes with some default configuration like second image.

I changed baud rate of SF11/C from 115200 to 9600 and tried. But again, there was no data. After that step, I changed serial output mode from “On demand” to “Continuous”. And boom, the data came.

Can we add to https://docs.px4.io/en/sensor/sfxx_lidar.html documentation which may help users who struggling this issue.

Furthermore, I wanted to try with I2C connection. But, I didn’t see any option for I2C in SF11/C menu. I saw the Firmware upgrading from this site https://github.com/LightWare-Optoelectronics/pixhawk-guide.

After Firmware upgrade SF11/C presents I2C option for Pixhawk like below.

I turned on “Pixhawk I2C compatability”. After this step, data came to the Pixhawk. Also, https://github.com/LightWare-Optoelectronics/pixhawk-guide should be add to “LightWare SF1X/SF02/LW20 Lidar” documentation. It may provide more understandable to how connect SF11/C to Pixhawk.

Thanks!