Hi Johan,
Thanks for your interests in Syncfusion products. We already have a sample on that in the Sample Browser with the name LiveChart. It is also available in the following location.
http://www.syncfusion.com/development/uploads/LiveChart_f7a8bd7c.zipKindly use this sample to know how to add points to the chart after a particular period of time.
Let me know if you have any queries.
Regards,
Athaur Rahman