It all depends on what you mean by "efficient"?I'm trying to make an IoT based project that works on Real-Time data accumulation, for that, I need to know whether the STMF0 series controller are efficient or not.
I do similar, but don't contact a timeserver (as such), I call a PHP script running on my webspace, and get the time from that - along with other information as well, such as if updated settings are available to download.If you did not want to add another board and work with I2C, AND it is an IOT project, an alternative that might work is to contact a Time Server on power up (and other times if greater accuracy is needed) and use that accurate time to set/reset the STM RTC. I used that approach recently (see here)..
You may mean (I am guessing that you do) these boards (bought on for less than US$2). I have had a couple of discussions about them.An issue with the DS3231 modules is their rechargeable battery - if you're running at 3.3V then the battery won't charge ...
Exactly, it's cheaper to buy the module than the parts.You may mean (I am guessing that you do) these boards (bought on for less than US$2). I have had a couple of discussions about them.
Although, using the DS3231 is so easy, you can also just make your own circuit (pride of making I suppose because the boards are cheaper than the components - at least in my case).