How to write the 8051 program to control the alarm??

[ru]

alarma 8051


Halo..

recently i'm doing a proj abt sensor.. i need to use 8051 program to control the alarm system..
its used to programmed so that the alarm will be trigger when the person being detected by the sensor..

is anyone of u all know how to search for the bitwise of the sensor?
or is anyone of u got the similar program of this?

can u all help me?? thanks...

 

[amazonite]

8051 alarm

You can use ultrasonic to detect person . Then connect the trigger signal to 8051 INT pin. When the ultrasonic detect person, will enable the interrupt sub-routine . you can wirte a sample code in this . and the external driver circuit can use BJT in common emitter mode.

 

[rodney25]

8051 program

or you can connect the sensor(it have to be ttl levels) to any port like p1.0 and do this

CLR P1.1 ;buzzer is connected to port p1.1

JNB P1.0,$
JB P1.0,$ ;wait for LOW edge trigger

alarm:
SETB P1.1
CALL DELAY
CLR P1.1

 

[ru]

edge trigger 8051 program



okie.. thanks...

one more thing is... how to connect the sensor to the 8051 chips??
do i need to add any components between the sensor output and the 8051 pins??

 

[rodney25]

programing 8051 interrupt alarm system

what kind of sensor & waht kind of output it gives?

 

[tutx]

how to write a programm in 8051

okie.. thanks...

one more thing is... how to connect the sensor to the 8051 chips??
do i need to add any components between the sensor output and the 8051 pins??

It depends on your sensors. Normally, we put a driver circuit between 8051'ports and sensors. Sometimes it is called an "applified circuit", sometime it is a current to voltage converter, and sometime it is a frequency to voltage converter, etc.

So, should remember that the microcontroller 8051 familly only accepts all signals with TTL standards.

 

[ru]

how to write program to microcontroller


I'm using the photoelectric sensor to detect the person and trigger a alarm output..
Actually the sensor is just a small photoelectric switches... required a DC 10V and current< 100mA..
When i test the sensor with the LED, the LED light up when sth is block in front of the sensor... but once i connect its to the 8051 and the LED directly from the output of the sensor, its light up once i turn on the power supply without sensing...
This is the problem i'm facing now.. don't know whether my program or circuit is wrong..
Got any idea from u all?? Can guide me??

 

[khafaji]

a sensor programming for microcontroller 89c51

can you tell the exact spec. of your sensor?
like the name of manufacturer and the number of it

 

[ru]

light sensors programing in 8051


It is a photoelectric reflex switches from a company called 'Sick'.. Part no: WT4-2N132
The Light source, light type = LED, red light..
The switching output is NPN..
Switching mode is light-switching..
NPN; signal voltage HIGH =Approx. VS
NPN; signal voltage LOW =< 1.5 V
Max. switching frequency= 1000/s

 

[ru]

8051 how to write program


Is there anyone can help me? i a bit blur already..
Really don't know how to connect..