I have done a simple project which measures CO gas in air.Now I want that sensor will measure the level of CO gas and sms will be received on android phone when the area is under danger zone.How to receive sms on android phone without GSM module?
There are exactly two ways of sending an SMS. Both of which require more than "just" an Arduino.
- Directly using GSM - for which you NEED a GSM shield
- Indirectly using an Internet Gateway - for which you NEED some form of internet connection.
Since you have an aversion to 1, 2 is your only option. So you require some extra hardware (unless you have an Arduino with built in WiFi or Ethernet) to connect your Arduino to the internet. Then you have to pay an SMS gateway provider to allow you to send SMS messages through them, and implement their API in the Arduino.
Also you need an internet connection available wherever the Arduino happens to be.
All in all a lot of work and you're really no better off than using a GSM shield.
Alternative from price perspective:
Assuming that you have internet at the location of sensor (WiFi or cable) you can buy a RaspberryPi (revision 3 has already integrated WiFi and bluetooth). Using python code you can than send SMS message using some free SMS service provider if there are any in your country using their API.
If SMS notificaion is not critical, you can use RaspberryPi to send an email or some other sort of notification. Heck you can even create a Twitter profile for your sensor and call it Mr.Sensor and then post tweets with sensor values. Possibilities are endless, it all depends on your use case and available infrastructure.
I hope you will find something that will satisfy your needs :)