Grove LED_bar without GrovePI

Hello, I have maybe stupid question but how i can control grove LEDbar. Bar has 4 pins and 10 led diodes. I searched whole internet and nothing. Is it somehow with I2C or with PMW . Worste is that there is no datasheet about inputs. (on Raspberry pi btw)

Thanks for every answer.

I have the similar question.
Is it possible to use the LED Bar V2.0 without the GrovePi. My SBC is a Raspberry Pi 2 Model B. I don’t have a need for all the sensor interfaces that the GrovePi offers. It is an overkill for me. I just want to be able to command and control the LED bar using those 2 pins D9, D8 using software. How do I do this?