Sensor Issue in Sim 900

[khandelwal.vaibhav7]

I have designed a board for intrusion detector using PIR sensor,ATMEGA328 and sim900. I have directly connected the sensors to the controller. But when i am sending or receiving call or msg from modem or to modem the sensors automatically get high. Any precautions to be taken? please throw some light.

 

[Batang]

Sounds like you need some RF bypassing on your sensor inputs.

You can also try moving the GSM antenna away from your sensor.

Cheers.

 

[khandelwal.vaibhav7]

Can you please suggest some bypassing techique??

 

[hobbyckts]

sensors automatically get high.

What is this means? Is your sensor providing high output always?
provide the part detail of the sensor you are using.