New Project - reminder service

i have recently started a new and my first project using an arduino uno. What this project entails is a infrared sensor determining if an object is present/or not in a black box and if it is there, send a warning to my mobile via sms using a GSM modem such as the wavecom. i know that i need a rs232 converter and from my reading i believe the MAX232 is sufficient, for connecting the wavecom to the arduino. I also want the ability to set certain user interface parameters in the arduino program via sms from my mobile through the wavecom back to the arduino uno.

I have some questions:

  1. Is this project viable?
  2. What variant of the MAX232 is appropriate? whats the differences?
  3. Is it possible to determine if the wavecom is malfunctioning and outputting an error message/red led on the arduino?

I am having some trouble implementing the system and starting off. any pointers or code examples from people with experience with similar projects would be awesome.

thats all for now,
Thanks

Rather than the external RS232 Wavecom modem you might be interested in the GSM Playground shield:

or the Cellular Shield with SM5100B:
http://www.sparkfun.com/products/9607

i have seen those options but i am on a tight budget. I was going to purchase a hong kong ebay wavecom for $30 and the maxim chip is only a couple dollars. However the shield option is a backup.
Can the shield be purchased as a build it on your own kit? a certain amount of the project needs to be pieced together/built by us.

Bump

(never tried myself but)

Have you considered "hacking" an old phone to send the SMS for you,?

  • some phones have USB/serial
  • you could hack the keypad ..

?

I can send AT+SDATATSEND=1,14 and press enter in Terminal v1.9b but all it returns is ">" and I don't know what to do next. I'm assuming its prompting me to input what I want to send, but I do not know how to confirm that input.
please help me

The > is probably the command prompt of the modem inside. Now you can send all kind of AT commands to the phone. You did not tell us what type it is.

if you send "AT\n" you should get "OK".

you could try to phone someone : "ATDT 555123456\n"
DT stands for Dial Tone - the number should be valid of course, eg your house number.

You will have to dive in the manuals of your phone or search the internet for the set of available commands for your phone.
These commands are called AT commands, or sometimes Hayes commands (as Hayes was the first to standardize modemcommands long long ago)

Succes,
Rob

Try the DS275 instead of the MAX232. No caps needed. :wink:

A quick Google search for AT+SDATATSEND seems to indicate it is for sending TCP/IP packets, not SMS messages.

AT+SDATATSEND=1,14 means "Send a packet of 14 bytes to socket connection 1 (previously established)

The ">" prompt gives you the opportunity to enter the 14 bytes followed by a Ctrl-Z.

Read more here: http://www.sparkfun.com/datasheets/CellularShield/SM5100B%20TCPIP%20App%20Note.pdf

johnwasser, the problem appears after I enter the 10 bytes.
for example:

0123456789 //then I push Ctrl+Z and nothing happens

and if i try to write another AT comand its not working...after ">" I dont know what to do

Morty,

What is the name and type of device you are talking to, either I missed it or you still did not mention it....?

I use SM5100B. but on terminal appears >
i have to write 1234567890 and press Ctrl+z?
or to write: "1234567890<Ctrl+Z>" and then to click OK?

how I read the manual / app notes you should :

1234567890 and then the CTRL and z simultaneously.

ok, but when I hit CTRL and Z simultaneously it works like copy/paste for the last character that I used on keyboard. any ideea for what to do?

it works like copy/paste for the last character that I used on keyboard. any ideea for what to do?

I don't understand....

Please tell all about the configuration you use:

  • What OS are you on, version ?
  • Which application do you use as terminal?

I use terminal v1.9b By Bray++ on Windows XP

The CTRL-Z is ascii char 26, have you means in your terminal to make macro's to send this as a special char?

with macro it works. set macro --> 1234567890$1A

Thank you very much, robtillaart

you're welcome,
Rob