Problem in Rain fall alarm system

[su1]

Hello everyone, I have to make a rainfall alarm system but it should be wireless such that if the sensor senses the rain then it must send the signal to a receiver which is placed at least 20 meters away from it. Can anyone help me in implementing it?

 

[captainshahid]

use rf transmitter module.
**broken link removed**

 

[henriquemiranda7]

You can use this bluetooth module: https://apirola.wordpress.com/2012/09/05/setup-jy-mcu-bt-board-v1-2/

You can use a PIC,MSP430 or Arduino, the board works with RS-232.

 

[tpetar]

No need for external modules, use uC with RF as one of options :

Microchip rfPIC serie
http://www.microchip.com/ParamChartSearch/chart.aspx?branchID=1201&mid=&lang=en&pageId=76

Atmel Single-Chip Solutions
http://www.atmel.com/products/Wireless/zigbee/single-chip_solutions.aspx

 

[su1]

Thank you for your suggestions friends. I thought of using the RF transmitter module but my teachers told to do it some other way. and i don't have any knowledge of bluetooth and external modules. But I will consider all three of them if you would please provide me with all the details some circuit diagram or something. Please go ahead for any new ideas.

 

[captainshahid]

have u knowledge of programming microcontroller? otherwise i will suggest linear circuits.

 

[su1]

Sorry for the delay in replying...i don't know much about programming a microcontroller so for me linear circuits would be better.....and captain please suggest a circuit which is easy to implement..hoping to see a reply soon.
thanks.

- - - Updated - - -

Sorry for the delay in replying...i don't know much about programming a microcontroller so for me linear circuits would be better.....and captain please suggest a circuit which is easy to implement..hoping to see a reply soon.
thanks.

 

[chuckey]

If you can't use RF then options are :- infra red, or ultra sonic, So the first thing to do is to experiment so as to decide which to choose. I would recommend using the presence or absence of a 1 KHZ modulation frequency as you signal source. using this will mean that it is much easier to filter out noise and hum from your signal. So select one of these methods and build it and see if you can reach the 20m mark reliably buy using a 1KHZ square wave as your source, and have it drive power LEDs and build a suitable receiver, Or modulate the ultra sonic carrier (~40 KHZ) and build a receiver.
frank

 

[su1]

can you provide me with a working circuit diagram of transmitter and receiver of infrared or ultrasonic?

 

[chuckey]

See post two below this one :-o
Frank