globalrev wrote:
i want to build a service where you can send an SMS with your
cellphone to my website and then the site will collect the
data you asked for and SMS it back.
so what components would i need for that?
Arguably the simplest route is to use a phone with a serial
connection to a computer, whether that connection be RS232,
USB, IrDA or Bluetooth.
For outgoing messages in large volume, SMS lodgement directly to
an SMSC (message centre) via SMPP over an internet connection
is likely to be a cheaper option in the long term. But that'll
depend on what's on offer in your part of the world.
There's probably some means of receiving messages without using
your own hardware, but I'm not aware of any details.
If using your own hardware, I'd suggest a cellular modem rather
than a handset. These are permanently powered by a low voltage
DC supply, rather than a battery you need to keep charged
without destroying it with constant overcharge.
And a modem is more likely to support text-mode command
interactions with your computer rather than raw PDU-mode
interactions. PDU-mode requires your software to translate
to/from the raw transmitted SMS data, but gives you much
greater control.
The rest is software, and your cost will depend on how you get
or develop that.
You might be able to get a SIM (assuming a GSM or UMTS cellular
device) with very cheap SMS rates. A pre-paid service will
limit your losses if your software ever gets over-enthusiastic
about sending messages.
John
