The SF11/C is not publish the distance data when the PX4Flow Smart Camera is connected.

[bozkurthan]

Describe the bug
Hello, I'm using SF11/C for distance sensor and PX4Flow Optical Flow Camera in Pixhawk 2.1 (Cube). I don't have an ultrasonic module on PX4Flow. My setup is shown below.

Like images PX4Flow Camera is connected to I2C and SF11/C is connected to Telemetry 1.
The bug is revealed when I connected both of sensor to Pixhawk. SF11/C publishes distance sensor when PX4FLow Camera isn't connected. But, When I connect the PX4Flow to Pixhawk, PX4Flow publishes Zero distance which mentioned before this issue PX4/PX4-Flow#101. In addition SF11/C cannot communicate Pixhawk when PX4Flow is connected.

Without PX4Flow Camera sf0x test and Current Distance Analyze

With PX4Flow Camerasf0x test and Current Distance Analyze

In documentations, Laser Altimeters sensor can be connect instead of Ultrasonic module. But, I didn't find any schematic for this.

I examined the drivers of PX4Flow and SF0X. They have same definition for Uorb distance_report topic.

PX4FLOW:
https://github.com/PX4/Firmware/blob/14ef009aabf5723b1a9f8fe5489844c961f05fab/src/drivers/px4flow/px4flow.cpp#L554-L566

SF0X:
https://github.com/PX4/Firmware/blob/14ef009aabf5723b1a9f8fe5489844c961f05fab/src/drivers/distance_sensor/sf0x/sf0x.cpp#L514-L528

Also they have same id for publishing. I tried to give different ID but it didn't work.
Furthermore, I just commented lines on PX4Flow. However, it didn't work as well.

To Reproduce
Steps to reproduce the behavior:

1. Connect SF11/C to Pixhawk Telemetry 1 and configure
2. Can be able to see Current Distance
3. Connect PX4FLow to Pixhawk I2C
4. See Current Distance Value Zero

Expected behavior
Pixhawk can be able to see correct distance values when PX4Flow and SF11/C are connected.

[bozkurthan]

@dagar fyi.
I wasn't able to test on I2C bus with same setup (I don't have 1 more I2C connector for this). But today I able to test with poor connection on I2C bus.
The problem is that PX4Flow and SF11/C must connect on same I2C bus because of PX4Flow driver. So, it can be close.
Here correct setup:

In addition, maybe it can be add for future request. (PX4FLow on I2C, SF11/C on Uart) Should I open new Issue or can we continue on this?

[hamishwillee]

This also looks related: #11227

[bozkurthan]

As far as I understand, it is not same issue. @60ericleal60 couldn't get any data from PX4Flow camera but I could. I just have problem with distance sensor.

[60ericleal60]

There is a solder bridge you need to fill to power the distance sensor.

[bozkurthan]

You are right. I saw that bridge and I tried to connect SF11/C to it with poor connection but the data didn't come to Qgroundcontrol. I'll try again with solder.

[bozkurthan]

This issue is fixed at #11724 by @DanielePettenuzzo . I'm closing and will continue on #11689