problem with dfrobot 50A current sensor

I intend to create AC current sensors to detect electrical circuit load .

currently I have a 50A current sensor DFrobot

  1. But according upload and compile the results on the monitor serial
    beregerak too fast and the data value is not fixed .

  2. I plan to make an indicator of current sensor measurement result ,
    using a relay module

For example if the load current of 10A , the relay ( NO ) into flame

anyone can help me to make a sketch

Best regards

Your link provided a sample program. What is wrong with that?