While building my homebrew home automation I wanted a way to monitor it remotely with my iPhone as cheap as possible. Well a land line was out, despite an extensive search I couldn’t find a way to make my iPhone 4 a dial-up modem for remote terminal access. I then went on to looking for an affordable cellular option.
I ran into a GSM device made by Topkodas out of Lithuania. They sell them on eBay for $170 under a posting of “GSM SMS Remote Heating Control Temperature Controller”. They also have them on their website.
After waiting what seemed to be pretty average for overseas delivery the item came in a surprisingly small box. They manual is a little painful to get through but I set mine up eventually. It took a few test text messages to get the texting to work. I has submitted a tech support request but cancelled it 12 hours later because I had figured it out. I don’t know how responsive they normally are but unless it was a Fluke it’s more than 12 hours out. That’s not to say I wasn’t happy with this device though. It performed just fine and it still works to date.
To get the cheapest possible service I purchased a AT&T no-contract phone. I yanked the SIM card, called tech support to have it unlocked and I was dialing into it within minutes. I recommend this product if you’re looking for something along these lines. Some surprised I was very happy to discover. Temperature sensor was remotely mounted and wired in; bonus! Fit well into a standard hammond box with a cut out for the SIM card and other connectors! Has good reception in low reception areas and has a removable antenna for antenna upgrades!