[SOLVED] pic16f877a pcb problem

[sudhii4u]

hello friends,
i am creating a research robot using pic16f877a. i connected 4 sensors MQ2, MQ6, LM35 and PIR sensor to pic. i can sent request sms to sim300 GSM connected to pic. it will replay me with the requested parameter like temperature. every thing is working fine on the bread board.
i designed and connected it on pcb, it shows some problems. pic16f877a is getting hanged after 10-20 seconds.. it shows a short circuit between gnd and supply(regulator IC 7805 is also getting heated) only after the pic is hanged8-O:!:. initialy there is no short between them. what is happening here?? can anybody help...
pls see the attached pcb layout and cir cuit diagram

 

[power_yang]

Do you have any short soldering or short PCB occurs on it?
You can send this DSN file and PCB brd file to my email: power.yang.china@gmail.com.
By the way, I also interesting in robot.
I will develop a robot with AVR processor in next month.
I think we can help each other,and become friend.

 

[sudhii4u]

sure yang. i am still working on my project, i cant figure out the problem yet.

 

[demetal]

Hi,
If its working fine in ur bread board then it might be the problem with the soldering and pcb design... If you are using a home made pcb.. Check twice the connections and tracks made...

Are you using any protector diode for your regulator ic... ?

Also check the voltage at the output of power supply (i.e; +5v) and at the regulator ic's input pin... Also check your regulator ic's pin connection in pcb...

Good luck.

 

[sudhii4u]

problem solved. its due to the sensors i connected MQ2 and MQ6. both these sensors need lot of current so the regulator IC will definitely get heated after somtime. so i connected a heat sink on the regulator IC. now it is working fine. thanks for replays.