# LiDAR LightWare SF20/C integration on I2C3

Source: https://forum.modalai.com/topic/4482/lidar-lightware-sf20-c-integration-on-i2c3
Category: General Questions (https://forum.modalai.com/category/2/general-questions)
Posted: 2025-06-04 15:23:18 UTC by george kollamkulam
Replies: 6 · Views: 1008

## george kollamkulam · 2025-06-04 15:23:18 UTC

Hi,

I am trying to integrate the LightWare SF20/C LiDAR on I2C3 port (J19) on Starling 2 UAV (VOXL 2 autopilot running Px4 on QGroundControl). I wanted to understand the following:

1) How can I reconfigure the ESC AUX regulator to 5 V (presently at 3.3 V)?
2) What are the steps to setup the LiDAR on Px4?

Thanks!

## Reply by Eric Katzfey (ModalAI staff) · 2025-06-04 15:45:06 UTC

@george-kollamkulam Regarding question #2 you will need to rebuild PX4. It currently only has the serial drivers built in for the Lightware distance sensors. So, in file `boards/modalai/voxl2-slpi/default.px4board` you would need to add the driver with `DRIVERS_DISTANCE_SENSOR_LIGHTWARE_LASER_I2C=y`. Once it has been built into the image then you can start it in the startup script `/usr/bin/voxl-px4-start` with the command `qshell lightware_laser_i2c start -d 4`

## Reply by george kollamkulam · 2025-06-05 15:48:57 UTC (in reply to Eric Katzfey)

@Eric-Katzfey Got it, thanks.

Can you tell me how to reconfigure the ESC output voltage to 5V DC? It's presently at 3.3 V DC

## Reply by Eric Katzfey (ModalAI staff) · 2025-06-05 18:45:26 UTC (in reply to george kollamkulam)

@george-kollamkulam Is that so that you can power your distance sensor?

## Reply by Alex Kushleyev (ModalAI staff) · 2025-06-06 14:19:35 UTC (in reply to Eric Katzfey)

@george-kollamkulam , is there any reason why you cannot use 5V from J19 on VOXL2?

Enabling 5.0V output on the Mini ESC would need a firmware update, so if you can stay closer to the standard configuration, it will be easier to maintain (for you and for us as well).

Alex

## Reply by george kollamkulam · 2025-06-06 17:18:03 UTC (in reply to Alex Kushleyev)

@Alex-Kushleyev Yes I wanted to power a 5V LiDAR. I could try to splice the 5V (pins 1,6) from J19 and use that to power the external sensor, if that's what you recommend. Are these pins limited to 5W (5V, 1 A)? If not, how much power can I safely draw out of that port?

## Reply by Alex Kushleyev (ModalAI staff) · 2025-06-06 19:50:30 UTC (in reply to george kollamkulam)

@george-kollamkulam That port is internally connected to the 5V coming from the main VOXL2 power (which is technically 5V 6A). Obviously you would be limited by the connector pins, which are rated around 1A max continuous. Also, drawing too much from this pin, can bring down the whole VOXL2 (if that 5V output on J19 is shorted to GND, for example).