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[on:]

Hey I'm looking to build a device which senses a certain ambient air temperature, then activates an sms unit to send a text message to a cellphone.

I'm not an arduino guru at all and would appreciate it a lot if any one had any advice on the types of units I should be looking at and the feesability.

I need it to be as small as possible with no other functions required.

Thanks in advance.

Preston

[Reply #1 on:]

I have no experience with sending SMS from Arduino but for taking a temperature I use several DS18B20 (Dallas Semiconductor One-Wire temperature sensor). They are easy to handle and quite accurate.

[Reply #2 on:]

HI, i also measure ambient temperature with 1-Wire Maxim IC DS18B20. For sending information to SMS you will need something like http://www.ebay.com/itm/NEW-GSM-SIEMENS-TC35-SMS-Module-Board-RS232-UART-Serial-Arduino-Voice-adapter-/270851051016?pt=LH_DefaultDomain_0&hash=item3f0ffb0e08
.

Connect DS18B20 to Arduino, Arduino to GSM module using RS232 some small programing and that is it

[Reply #3 on:]

I need it to be as small as possible

The easiest way to obtain SMS capability would be to use a cellphone shield, but that means your device has the footprint of a UNO. It's possible to get much smaller Arduinos (down to a single 8-pin DIP chip if you like) but you would be ruling out these smaller packages if you are using a standard shield. So, I suggest you need to decide how important 'as small as possible' is to you and what size is actually acceptable. If you're aiming to make it smaller than a UNO then you have a compromise to make between size and difficulty.

[Reply #4 on:]

"If you're aiming to make it smaller than a UNO then you have a compromise to make between size and difficulty."

Smallest is best for this application, when you say it will be difficult do you mean impossibly difficult or just pain in the butt difficult?


"Connect DS18B20 to Arduino, Arduino to GSM module using RS232 some small programing and that is it"

Brilliant, do you have an idea of the size that this would be as a finished piece?



Thanks so much again for your time guys/gals.

[Reply #5 on:]

"If you're aiming to make it smaller than a UNO then you have a compromise to make between size and difficulty."

Smallest is best for this application, when you say it will be difficult do you mean impossibly difficult or just pain in the butt difficult?

Yeah, but how small do you NEED? Put another way, how big would it need to be for you to reject it out of hand?

If you can use a UNO footprint that means you can use any of the standard shields - they will just push on top of the UNO and you will run the example sketches and have something that more or less works out of the box. If that is too big you have a much more limited choice of hardware and may need to integrate your own solution. It's all doable, but the time and skill required increases significantly.