So, last year I was interested in building a clock ... old fashion type with hands.
I got some advice.
At the time I had not even touched an Arduino.
Well now I have a better grip on how things work ... but I still have a few questions.
To keep things simple, lets just look at one clock dial ... the second hand. Lets assume I am going to have three separate dials so I don't have to worry about a shaft within a shaft.
So, as you explained (and since have come to understand), steppers come in fixed steps ... usually 200 or 500
Great ,,, but that does not divide into 60.
We had talked about gearing the step motor so I get 360 steps ... any ratio of 360/200 ... say 54 teeth on one gear and 30 on the other ..... or 72 teeth and 40 teeth.
Any of these will give me 10 steps per second.
I was about to got this route ... then I started thinking ....
What if I put the hand directly onto the motor?
I know I can't get the right number of steps ... even using micro steps (1600, 3200, 6400 ), nothing divides to get 60 divisions.
But what if I put a rotary encoder on the motor?
I see many have 600 divisions per rev.
Andy thus my question .... if I did this, can you just drive the step motor more or less constantly and use the "enable" to stop the motor every 10 pulses from the encoder?
I am thinking I would set the drive as high as it would go ...6400 ... hit enable .... the Arduino would be sending out pulses, don't even need to count .... instead count the incoming pulses ...when I get 10 then disable the drive. I would wait say 1/2 second then enable the drive ... count 10 incoming pulses and disable again.
Maybe I am missing something? Maybe it would over shoot?
I have added the complexity of an encoder but now it is direct drive ... no gears.
Just wanted to pass the idea past you guys .... step motor with gears or direct drive with encoder (if it will work) ?
Thanks!