GSM based home security system

[Paro Maheswari]

Hey friends i am working on the project , but i am stuck on the very 1st step ie crystal ocillator is not working properly ie its not giving the 11.0592 frequency output .
i am using at89c51 microcontroller .
i have changed the µcontroller 3 times n the crystal but still i dont get a frequency output of 11.0592.


please tell me the reason's that can be responsible for not getting a correct output frequency.

 

[ckshivaram]

check the capacitor associated with crystal. it should be 22 or 27pf

 

[anj]

you are testing your crystal?? how??

 

[ckshivaram]

you are testing your crystal?? how??

crystal can be tested using CRO or a good multimeter capable of reading frequency of that range.

@ Paro maheswari: you dont need to insert the controller to check the crstal oscillator. check if the crystal oscillator is connected to controller properly, and see if the capacitor is grounded properly. Also check the value of crystal oscillator.

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also try with 33pf capacitor for crystal. usually that is the normal working value for crystal