getParam() cannot be used

[tablejai]

Hello I am trying to use the subscription feature from your library.

After I create the instance for NodeHandle as nh, I tried to subscribe to the topic on my ROS system. However, I failed to retrieve the values I need from the topic using getParam().

Can you show what is the proper usage of the subscribing feature of your library as there is not much examples and resources about how to do it.

[tablejai]

FYI, I am using a Nvidia Jetson Nano using ROS Melodic and a STM32F409. The two of them are communicating through UART. The publish works for me but then subscribe doesn't really quite though.