VL53L1X Lidar running at < 1Hz when docs say it should be 50hz

PX4 Autopilot Drivers & Sensors 🔧
1

Hi, I just bought and connected a VL53L1X lidar from holybro to my Holybro rpi 6x flight controller. The lidar connects fine to the i2c port and after setting the parameter SENS_EN_VL53L1X to enabled I can see the DISTANCE_SENSOR mavlink messages in QGroundControl’s MAVLink Inspector. If I have the flight controller connected to the computer running QGroundControl via a usb-c cable the DISTANCE_SENSOR messages come through at a solid 5hz, but when connected via 915mhz telemetry the DISTANCE_SENSOR messages come through at about 0.2hz (the frequency measurement keeps changing between 0.8hz, 0.2hz, and 0.0hz) - a rate which makes it useless for collision avoidance or precision landing. The docs indicate it is capable of running at 50hz.

Would anyone know what is going on? I can’t find any params to increase the frequency, and it would be greatly appreciated.

2

Have a look over here: How to increase tf mini frequency - #5 by JulianOes

3

Thanks, this opened up a new world of mavlink console commands to me.

1 Like
4

Hi @generalauto

Just wanted to ask if you were able to run the VL53L1X LiDAR @50Hz when sensing for long range (up to 4m). Cause when I am running uorb top -1 in the mavlink terminal in QGC its limited to 5Hz. I think its because of this PR on GitHub. Would be nice to know if it was possible to run this LiDAR also @50Hz when using in long range mode.

5

The sensor is only capable of higher frequency when in short range mode, which caps the distance measurements to ~2 meters. The default sensor in long range mode runs at about 10 hz " 10 Hz in Long-distance mode." taken from: https://www.st.com/resource/en/user_manual/um2510-a-guide-to-using-the-vl53l1x-ultra-lite-driver-stmicroelectronics.pdf

In long range mode with greater than 5hz I noticed the max range is very limited, something like around 3.5 meters instead of 4. This outdated sensor really comes with a lot of tradeoffs. You can have 4 meter ranging but not at 50 hz, or 50hz but not 4 meter ranging.

If you are looking to run sensors for collision prevention I would recommend the SF45 by lightware lidar. For a range aid sensor (height sensor) would recommend tfmini plus

2 Likes