Sensors type

Dears 

I want to make a device that will monitor the car using several sensors to detect the baby inside closed car what are the specifications or the best type of  sensor are you advise me for the below:-   

- a temperature sensor,

-a motion sensor,

-a sound detector,

-a carbon dioxide sensor.

The scenario when the car stop and close the device will start to monitor a temperature and a carbon dioxide threshold if it above or in threshold will start monitor baby by his motion or sound if detected will trigger the buzzer and open the windows and send SMS with give missed call 

Your advice and support is highly appreciated 

 

Temperature sensor, simplest and cheapest is a thermistor, but they need calibration. There are a whole lot of semiconductor temperature sensors, both analog and digital, with good absolute accuracy, that will work well over the temperature you are interested in. There are one wire, I2C and SPI parts, but if you have a lot of other analog parts, microphone and motion sensor for example, then the ADC specs on a uP may be important.
Motion sensor, possible that a baby, particularly if it has been subjected to a high temperature, would move enough to trigger many devices, it depends on where you would be able to place it. It is possible that simple tilt sensors using accelerometers might work, but you would have to play around with false triggering is my thought.
Sound detector. There are small MEMS microphones available, sort of thing used in cell phones.
Carbon dioxide sensor, again, MEMS devices are available.
Many of these devices can be bought on small boards from places like adafruit, sparkfun, since some will be surface mount parts.
I have not given you more specific information, since you are going to have to work through issues like cost, size, accuracy, temperature and dynamic range, power consumption, etc. Keep it in mind that the devices will all have to work as high as sixty C or more.
Hope that is of some help,
Richard

Thanks dear
actulay i want to use it to monitor temperature and a carbon dioxide level inside closed car if it detect above the level will check if there motion or sound of the baby if it detect will send SMS ,open windows and trigger the buzzer

TAKE THE BABY WITH YOU

This only for who forget the child not for parents for school bus driver due to child may be sleep and driver thinking all children already left the bus and he closed the bus and put the child in dangers situation which cases die child.


In recent years, there have been a number of incidents where babies are forgotten in a car. During a hot summer day and in direct sunlight, a car’s interior temperature can reach as high as 150° F. Within minutes, a car can become a hot furnace exposing the child to life-threatening conditions. For these reasons, we are designing a device that warns nearby pedestrians if a child (or a pet) is trapped in a hot car.

You have a switch that detects when the driver leaves his seat and the alarm goes off after 3 seconds. Cost 20 cents for the switch plus $4,999 for the loud alarm and the built-in taser.

For the edification of those who may wonder what this issue is all about, read fully the brief article below, obviously not a bus, but there are some technical details,
http://www.stuff.co.nz/national/65250225/Baby...-Boy-left-in-car-at-Whanganui-Hospital-report
Richard