HC-SR04 Sonar Rangefinder

Is this not compatible with i2c?:question:

looking at your board my instinct tell me that your sensor is GPIO, the one with the arduino board can be wired on i2c.
In my opinion better you look for another rangefinder

Is this something for an arduino board?
Is it not compatible with Pixhark?

the pic of the sensor attach by fred_fr is with the Arduino board flashed with a code, so can communicate with the ardupilot firmware.

On the pics i’ve attach you can see its work…but i will not use it for fly

I will purchase and install an I2C compatible sonar.

You can look for a TF mini lidar or teranger evo 60, its up about the use you need