Hello! The Code was from stackflow so i tought it will okay, but of course, better code are always better! But i don't finde a better one. 
After i cleare the DC with the code from here i get an okay wave form, i will searche for a filter to get a cleaner wave form and then i want to get the peak value from the last wave, maybe to get an better AC Peak value its a good idea to save 3 peaks and to divide it.
PS: I need some other values to, but its better to make it step by step. I also need the peak numbers from 10 seconds so get the puls (peaks per minute), but first i need the peak value (like in the image) 