How to use geekworm Motor-Hat robot expansion driver for raspberry pi 3B with ROS

edit

hi guys! first of all im very sorry for my english, ill try to be understandable

im very very new to ros, just finished an online course for begginners and now im trying to implement what i learned on real life applications.

the issue: trying to write a ros code including a Geekworm Motor-Hat robot expansion driver without success.

HW:

1. raspberry pi 3B with ubunto MATE on it
2. ros melodic
3. Geekworm Motor-Hat robot expansion (link to this board on amazon)
4. raspi motor-hat driver - by alictronix link to this driver on github

things i have done:

• succeeded in writing python code using the motor-hat driver without ros for pwm servos and dc motors

• i guessed from the begining that trying to execute it with ros and without special adaptations wont success, but still i tried it just to see the error, so finally i got : “ImportError : No module Raspi_PWM_Servo_Driver” (tried to execute the pwm driver from the motor-hat driver package)

• read about ros wrapping in this link - Create a ROS Driver Package – Introduction & What is a ROS Wrapper and tried to implement it with my code, but no success on this one.

the help i need:

i really need a good instructions (if u can make it step-by-step instructions it will be the best) for a ros-beginner- on how to use non-ros packages\drivers like the one im trying to use. i think this issue im trying to handle with is a simple task to do and very important one but at this point of time i dont have the enough tools to succeed.

thanks to all who will do an effort to help me! i appriciate it!