Relay on/off - reset of the mbili

Hello

I am testing Sketch without connected physical relay, works perfectly 2 day and send every hour on server temperature.

But problem is when connected relay , then the mbili reset, works few minutes and crash … hmmm

google say " RC snubbers" solve the problem, i am do not know

I wonder if anyone has experience with this problem and how to solve it,
thank you in advance

I forgot to say that relay runs a small AC motor 220V, 4VA, very small

Hmm, you connect a relay, how did you do that, did you use diod protection and are you sure the mbili can drive the relay ?

grove relay , http://www.seeedstudio.com/depot/Grove-Relay-p-769.html

i am not use diode protection , mbili why not drive relay 100mA on grove pin , not a problem

problem solved,
explanation on the following link

https://arduino-info.wikispaces.com/RelayIsolation

Do not use this relay ever : http://www.seeedstudio.com/depot/Grove-Relay-p-769.html