hi,
i want to make a security system which may have following features
motion detector
smoke, gas leakage detector
wireless sensors
auto dailer gsm/fixed line etc
cctv camera interfacing.
hooter, alarm.
does any body like to help in development of this project.
till now i have planed to make use of microcontroller for main controll unit. gsm module for phone dailing. rf transcever for communication. and mp3 decoder chip for voice messages.
can any body help me in choosing the best microcontrooler.
First of all, you have to design the system in block diagrams in order to figure out how many inputs and outputs you have.
Second, select microcontroller that meets the above requirements.
Third, design the system b-by-block and make sure that each block is functioning standalone. Then connect them all together.
i have integrated three sensors with each other
i used the pic controller because it has the built in ADC
my one controller was attached to two sensors
the second controller had the sensor plus the wireless module
i run a timer isr of every 250 msec , in which i send a request to the first controller , in the response of this, my controller sends the data of the sensor to the controller having wireless module
after receiving and parsing the string i send the data through the wireless module
for the motion detector i used the PIR sensor which gave the high signal if there is any motion
if ur motion gas leakage and smoke detector are giving the digital out put then u can connect these with the one controller and can poll the data of every sensor and keep incrementing the some conuter in the response of every valid allarm of the sensor
if the no of count increase from defined limit ,
u can send the data through the wireless sensors and at the same time u can run the routine of sending the message via gsm module and can also run the buzzer
u can do all the job with one controller easily running @ 20Mhz
Hi, im doing a similar kind of security system too. I hv built the pir sensor based on the schematic below. But can anyone explain how it works at each stage of the circuit ASAP?