# Holybro VL53L1X Lidar Support?

Source: https://forum.modalai.com/topic/4067/holybro-vl53l1x-lidar-support
Category: General Questions (https://forum.modalai.com/category/2/general-questions)
Posted: 2025-01-07 21:00:59 UTC by Gary Holmgren
Replies: 1 · Views: 1015

## Gary Holmgren · 2025-01-07 21:00:59 UTC

Hi i have been following along on [this](https://forum.modalai.com/topic/3966/voxl-2-external-rangefinder-compatibility?_=1736277986191) forum post about connecting an external rangefinder to VOXL 2's J19 QUP3 i2c connector for altitude/landing purposes. I have the [Holybro version](https://holybro.com/products/st-vl53l1x-lidar?srsltid=AfmBOoo0n2F0KDZBzloIbpFaAGYz-nvQsj334atI_R0P7Uv5fVqRF24q) of this VL53L1X sensor. [Supported in PX4](https://docs.px4.io/main/en/sensor/rangefinders.html). I am wondering if anyone else has tried to make this work directly with PX4 through the DSP. 

I had tried editing the parameters for EKF2_HGT, and EKF2_RNG_CTL. As well as adding  SENS_EN_VL53L1X 1 to the startup script. when I manually configure SENS_EN_VL53L1X 1 in QGC with the mavlink console (parameter is normally hidden) it works to enable it. However when I try to use SENS_EN_VL53L1X 1 in the voxl-px4.conf in EXTRA_STEPS=() file and restart voxl-px4 then QGC is no longer able to connect to voxl 2's px4 instance. Either way the distance sensor data is not being published or working correctly. I have triple checked my wiring to be as follows:
![c6c030f0-7782-494c-875a-976aaba5891f-image.png](https://forum.modalai.com/assets/uploads/files/1736282720224-c6c030f0-7782-494c-875a-976aaba5891f-image.png) 

I also noticed for DISTANCE_SENSOR=NONE a comment states: "Options include: [NONE, LIGHTWARE_SF000]  " is there a plan to include more options here or is this being replaced by the voxl-rangefinder-server. 

It appears ModalAi's forked PX4 does include the drivers for this as shown:

![c603790b-07c9-40e0-94f1-14a9f6015ec0-image.png](https://forum.modalai.com/assets/uploads/files/1736283051306-c603790b-07c9-40e0-94f1-14a9f6015ec0-image-resized.png)

## Reply by Gary Holmgren · 2025-01-07 21:35:39 UTC

@Gary-Holmgren Figured it out, I hope this helps others with a similar setup.

I didn't notice before but in the usr/bin/voxl-px4-start script there is a comment:

 ```
# qshell vl53l1x start -X -b 4
```
Which you can make or replace to change the DISTANCE_SENSOR condition to:

```
if [ "$DISTANCE_SENSOR" == "VL53L1X" ]; then
	# Make sure to set the parameter SENS_EN_VL53L1X to 1 
	qshell vl53l1x start -X -b 4
	# qshell lightware_laser_serial start -d 7
```

Then you can change the voxl-px4-conf to: 

```
DISTANCE_SENSOR=VL53L1X
```
After setting the relevant distance sensor / EKF2 params in QGC you should be able to restart voxl-px4 and the distance sensor will appear!