In 2009, I could send and receive text messages though SMS gateways that would control my arduino-controlled hot tub that my friends and I got for $100 on Craigslist. I could adjust the temperature and it would acknowledge and tell me when the programmed temperature would be reached based on the time derivative. This was useful as a grad student in Ann Arbor winters.<p>I had a python script running on a handmedown computer running Ubuntu 8.10 that just periodically checked an email account, parsed the command, flipped the relay as necessary, read the temperature rise, and replied.<p>Writeup: <a href="https://partofthething.com/thoughts/hot-tub-controller/" rel="nofollow">https://partofthething.com/thoughts/hot-tub-controller/</a>
If you want to use this as a toy, sure. But please don’t rely on it for messages you want to actually get delivered: These gateways frequently drop messages for random reasons, or block your IP if you send more than a few messages at a time.
Also, in countries other than the US, expect the gateways to be long gone, or completely unreliable.
Tangentially related: it's fascinating how much of the cellular messaging network runs on (or at least speaks) SMTP and IMAP. These SMS/MMS gateways are just one example; Visual Voicemail[1] also runs on IMAP and it also shows up in mobile terminal (i.e., phone) testing standards[2].<p>[1]: <a href="https://www.gsma.com/newsroom/wp-content/uploads/2012/03/omtpvvmspecification12.pdf" rel="nofollow">https://www.gsma.com/newsroom/wp-content/uploads/2012/03/omt...</a><p>[2]: <a href="http://www.omtp.org/OMTP_Terminal_Testing_1.0.pdf" rel="nofollow">http://www.omtp.org/OMTP_Terminal_Testing_1.0.pdf</a>
Aren't these basically open relays for SMS? Wouldn't they be buried under an avalanche of spam? I'm honestly mystified at how and why carriers expose these free SMS gateways. Am I missing something?
Back around 1998 I built a Nokia phone and interface in Flash 4 that you could actually use to send me an SMS message using this exact technique behind the scenes. Unfortunately it was interesting and novel enough that it made German TV and while sat at my desk one morning my phone suddenly started buzzing constantly as a non-stop flood of messages in German started coming in. I had to turn the phone off and when I turned it back on after work it buzzed until it basically filled up and then never worked again. I had to buy a new phone and disable the message sending of the Flash site.
I skimmed the post but couldn't find out how one would know what provider to use. I guess you could ask whoever you're texting with but that's not very reliable, not everyone knows, and people change their provider.
:) Brings back memories of doing this in 2002 to blast out Student Government campaign messages to students on campus. Back then email servers were very forgiving. I just had a loop that generated all combinations of <phone-number@carrier-x> and send out an email from a campus IP address via sendmail. It was a very effective way to send notifications at almost zero cost.
Man, I remember doing this around a decade ago back before some of my friends abroad had smart phones, being able to message them when they were away from their computers had such a fun novelty to it.
This is clever but due to the astounding amounts of spam and scams I got through that mechanism (not this script specifically), I had to set this to blocked on my T-Mobile account.
We used to offer such a free SMS gateway at ActiveXperts.com. Now moved to AuronSoftware.com and hid it a little better.<p>It's meant for trial users to be able to test our software without having to have a subscription or GSM modem.<p>But those gateways saw / see a <i>lot</i> of abuse. Even though we clearly state that each trial user only has 10 free messages we still regularly get an e-mail from an angry 'trial user' because only 10 messages out their 50K+ phone number mass mailing arrived.
This article reminded me of years past when I would marvel at the Nokia 6110 and how easy it was to send text messages while exchanging message centre numbers that gave me and my friends the ability to send unlimited messages for free.
Back during my phd I worked in a project that set up sms transponders onto the handles of water handpumps in kenya.<p>So whenever a pump was misbehaving or broke, we would observe it all on a webpage and a technician would be alerted to fix it.<p>Later on some ML was strapped to the SMS data to predict failing pumps before they failed.<p>Good stuff. sms can be very powerful in the right setting.<p>Don't know what the author means by free here though. Sms is something you pay for, one way or another.
The primary limitation here is inability to receive responses back from users. From a business revenue generation angle, that's probably not enough of a feature set to monetize for the carriers.
I remember in the UK in the 90's you used to be able to set your phone's SMS message centre to one in EG Finland or somewhere and be able to send all your texts for free.
sadly, this seems just to work for the US, my country (in the EU) does not have such free services anymore, there used to be such a service in the 90s, unfortunately it has been discontinued