It's too bad that you can't just send data directly, but I guess this probably means that 2lemetry will require specific structured data and will limit requests. They say the limit is TBD which is pretty vague and not very inspiring.
> We are modeling data limits around scenarios where a sensor value is sent to an HTTP endpoint once or twice per minute. Expect final rate limits to be in that range. For specific questions on increased rate usage, please email us at info@2lemetry.com. Higher end plans are available.
There are several unlocked GSM shields and modules available with working libraries and tutorials for under $50, using the exact same GSM module (SIM900): http://dx.com/s/Sim900?category=499
And so is this: http://dx.com/p/arduino-compatible-gsm-gprs-shield-wireless-...
And this (includes an Arduino Uno compatible board for $80):http://dx.com/p/elecfreaks-diy-gprs-gsm-learning-development...
It is dependent on independently operated base stations to relay data to the internet, and since all transmitters contend for the same frequency it may not be feasible in high-use areas. You also need a Ham technician license (35-question written exam).
On the plus side, it's totally free to use.
Wiki on APRS: http://en.wikipedia.org/wiki/Automatic_Packet_Reporting_Syst...
Live feed of beacons in the SF Bay Area: http://aprs.fi/#!lat=37.87810&lng=-122.27100
I queried the creator on kickstarter... he said $3 a month would be a worst case cost for said connectivity after your initial year is up.
Perhaps more importantly, he indicated that it would be possible to not use their server as a middleman, but that they need to get their analytics right before allowing that. Currently going through their server allows them to maintain sane data rates, apparently.
Personally, I couldn't find a one-off GSM data only SIM for less than $8 a month in my searches... even at multiple year prepay... so this sounds like a pretty good deal. I'm maybe more interested in just the cheap dumb pipe option, but really their "middleware" server does sound handy.
Are there technical reasons for this, or is it just designed to shut out competition?
