Relay Switching Problem

[ecworks]

hello Friends,
I am new in this forum,thank you very much .I am doing an automation project.In it i use a PIR sensor for human detection with an input shift resister and atmega 32 controller...data communication is through Ethernet module...The output of the PIR sensor is 230v so i cant give it directly to the input shift resister so i used a AC relay(coil voltage is 230v). My problem is that when AC relay switch some time my controller going to stuck and stop communication, when i reset controller its start to work fine...so how can i solve this problem,when relay switch some time my controller going to stuck.here i attached the circuit of connection.I hope my friend can help me in this issue.. Thank you very much

 

[Sunnysky]

You show a lack of attention to details, which leads be to believe you have major EMI crosstalk from coil or contact current getting into the logic.

Without more details on layout, part numbers and grounding, there are too many things wrong.
Try a small cap between ShReg input to ground,.