I have a little project in mind to surprise the wife with. Let me give you a little background:
She's a primary school teacher. Depending on which subject she is teaching at a given time in her class she has to use 3 different languages. So, for example, art is in English but Maths is in Spanish. This is not ideal as it can be confusing for the children (ideally you would use different teachers for the subjects in each different language) but it is the situation she has to deal with. She was trying to think of a way to make it clear to the children what language they were speaking in at a given time: Different hats, an armband, etc but as I pointed out, at the end of the day it is human nature to stop doing any of these things as it just ends up being annoying to have to change the piece of clothing every 50 minutes.
As a surprise I want to set up something with a low power draw (so it doesn't have to be plugged in but can run off batteries) that displays the language for a given class. My thoughts at the moment are as follows:
a) A screen of any kind is going to have a higher power draw so my idea is to build some kind of windowed box, sort of like a clock, with a disk printed with the corresponding flags to the languages and have an electric motor rotate said disk by the appropiate amount to display the correct language at each given time.
b) Whatever I use to control the motor is going to have to have a internal clock of some kind to be able to know what time it is at a given moment.
c) I am going to have to be able to program in the class schedule so it knows to what position to place the disk in at a given time. Because the class schedule changes depending on the day I can't just have it turn on for a set amount every X seconds.
d) the language for a given class doesn't always happen in the same order. It isn't always for example language A then B then another hour of B then C then A so sometimes I will have to turn the disk 2/3 of the way, others 1/3 sometimes have it still for two classes, etc. So either I will have to programme a routine for every single day or if it exists, find some way to detect what position the motor is in so I know how far I have to rotate to set a given language.
I do have to mention that while I am computer literate and hava used a soldering iron in the past, I am in no way experienced with this kind o thing. I intend this to be a fun summer project for me and a chance to learn some new skills.
I would welcome any advice on the feasibility of this project and any pointers in the right direction. Some specific questions I have are:
Is an Arduino the right device to control something like this? I wanted to avoid something like a raspberry pi as even though it is probably easier power usage is kind of a priority and I want to reduce it as much as possible.
Is even an Arduino overkill and if so, what other options do I have?
Do electric motors which somehow "know" what position their axis is in exist? If not are there any which know how many turns they have made so I can somehow, using gearing, have some kind of knowledge of the position of the disk at any given time.