I working on Smart Switch ZigBee device with a switch-mode power supply and I facing with a big problem - noise EMI.
My device include: power supply + relay below and MCU above.
I can control LightBulb, but when I control electric fan, it make my system hang and watchdog can not work. I have to turn off power and re-supply to fix it.
What should I do? Using shield or anything else?
Thank you so much!
If you can share your schematics/ gerber I can check it and make some recommendations.
If you have a relay I am thinking you have two different voltages, one for the digital and other for the power, but is it a AC voltage? Do you have enough capacitor on VDD?