Hello everyone, i have some doubts about few things on a project i´m starting, a Flip Clock.
This is an image from one of it :
So i'm thinking to use for it:
Arduino mega.
a Tiny RTC I2C module
3 stepper motors
some buttons switches
and more stuff not very important right now
The Arduino will read the RTC and move the motors.
So i though of using arduino mega 'cos of its amount of pins, because the number of components i will need.
and i don't really know if is right to use it or is better anotherway?
Also i don't know if atmega microcontroller is ok for been active continously or is there any problem?
Well i'm waiting to solve this doubts to continue with the project.
Thank you!
Any Arduino, even the smallest, can easily control three stepper motors. You will need external "step and direction" stepper drivers but you can get the "stepstick" for under $4 on eBay. You won't need the "direction" pin since the mechanism will not work in reverse. That means three data pins for the motors.
The I2C RTC takes two pins.
That leaves about 15 pins for buttons. You can get 16 buttons with 8 pins using multiplexing.
You may need to add some feedback switches so the Arduino can determine the displayed time and date in case of a reset.
johnwasser:
You can get 16 buttons with 8 pins using multiplexing.
Better yet, you can get 16 buttons with 5 pins using a 74HC4067.
With two 74HC4067 and a transistor to invert the CE line to one of them, you can get 32 buttons from 6 pins.
Although I've not tried it, it appears possible to get 64 buttons from 7 pins using 4 * 74HC4067 and half of a 74HC139. Much above that number of buttons might be problematical, due to having to cycle through all the possible addresses and the latency of that. It would depend on how fast you need the buttons to be read. For my 'fingerpoke' speed buttons, it wouldn't be much of a problem.
