How to interface GrovePi card on GPIO with ROS ?

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Hi,

I'm working on a robot running with RaspberryPi. For the ultrasonic sensors my choice was to interface it with my RPi trough a GrovePi hat provided by Adafruit. I'm perfectly able to get the distance information on my terminal. The next step for me is to publish this information in my ROS. I tried to write down a node who read information from the sensor and publish it but it does not work. Grovepi is unknown apart form the GrovePi folder. Any idea about how to use GrovePi away from the native folder. Thanks a lot