Rrespected sir,

I make software in embedded language. when i connect the microcontroller to any external device or i switch the external device by the microcontroller, i face the noise problem. In Hardware part i am sure this is ok, beacause i make necessary step, like i put a filter circuit and torroid. So please suggest me, need change the software routine or take any other steps?

Please give a reply as soon as possible.

Thank you,
TMS

 

Dear TMS,

You will always have such problems if you are deriving inductive loads. remedial action may be as follows:
Keep microcontroller supply separate from other
use optocoupler
use pf capaciter for power filtration
use debouncing routines for inputs
Try to use DC relays to activate the output
Use antiparallel diode with DC and snuber circuit in all AC outputs

I have tried and found above steps very useful.

TMCPK