I was looking to get a dedicated Waveshare GSM HAT for the Pi but Twilio is so dirt cheap that I never really got into messing around with a DIY solution.
In my experience it's very unstable however. Sending and receiving SMS can take anywhere from 5 to 30 seconds, and the modem can't do both at the same time. I tried configuring gammu's timeouts, loop delays and whatnot, but couldn't get something that's reliable enough for production.
Very very strange I'm the author of the article and I created this post and got the first few comments then when I reloaded the page it says you posted it and I can't upvote the post like it was my own.
What gives? Do you work for ycombinator or somehing? Or did you post it shortly before me and the mods combined our posts and attributed it to you?
I see what you did there.
I just read your article, thought it might be of interest to HN and posted the link here.