I'm wanting to build a small lockbox that automatically locks during a set schedule (in this case during the week and then unlocks on weekends).
I already bought the UNO r3 and two servos from amazon (only using 1) and I already have the enclosure designed and made, I just don't know anything at all about code, and now after reading some more I think I might need a secondary board to control the time(?). Any help would be appreciated! Even just a start or a link to something similar! (I've found a number of articles about servos and I think that I can figure that part out, but I haven't found much about calendars).
Thanks in advance!
You will probably need a Real-Time Clock (RTC) chip with a battery back-up to keep track of time. The Arduino alone is not very good at keeping track of time, especially if the power is ever disconnected.
Thanks for the quick reply! This is what I was hoping not to hear, but expecting at the same time.
I don't know how to code, so this was supposed to be a small side project for fun and to learn a little, but hopefully with less overhead than it is seeming like it's going to be.
Say I do end up buying the RTC and a battery backup, is there a relatively simple calendar to set up from that? Also, is there another Arduino board that may already have this functionality built in? Or another microcontroller altogether? I think I may have read at one point that the Arduino Zero had a built-in RTC?
I am not sure about the Arduino Zero, but it would most likely be cheaper for you to get a cheap real time clock to do this. Also, the Zero can only run at 3.3v so you have to see if it can work with your servo. If not you should stick with your Uno as it is probably good enough. Or you can power the servo externally.
Another option is an ESP8266 based board (like WeMOS or NodeMCU), have it connect to your home WiFi and get the time over the Internet (NTP). Probably more complex though than Arduino + RTC.
There are time libraries for Arduino that allow you to deal with dates and so directly, making that part easy. The problem remains of having the Arduino know what time it is when it's switched on, and to keep it running on time (it's typically off by a few minutes a day without external help). That's where an RTC module comes in. Set the time once, and as long as the battery doesn't run out it'll have a pretty accurate time available.