My 15yr-ish old watch winder broke down. My plan is to repair it with an arduino. I went to the shop today and, per the advice there, bought an Arduino micro and a Adafruit 2448 / TB6612 motor driver breakout board.
Here's what I've got:
9V power supply
9V dc motor
I/O switch (2x)
I/O/II switch
Arduino Micro
Adafruit motor driver My goal:
The motor has to make 800 rounds per day (x minutes per hour). Full power, bidirectional.
Even better would be if I can use one of the switches as an on/off switch so I can leave the power plugged in without using it.
The problem: I have no clue what I'm doing / what to do. I only know that it's possible to make it work. Images of the Arduino micro pinout make almost no sense to me.
I was thinking this so far:
+9V on 'VIN' on micro
on GND (next to 'VIN') on micro
DC motor lead on 'motor a 1' on the breakout board
DC motor lead on 'motor a 2' on the breakout board
You will save yourself a lot of grief if you start with the simple projects that come with the Arduino IDE (programming package) to learn the language and special features before tackling the winder. There are many motor driver tutorials available, too.
Sorry I didn't specify more. The idea is that the watch winder will keep your watch wound when you don't wear it for some consecutive days. In my case, the watch manufacturer specifies 800 turns per day.
800 turns per day translates to 33,3 turns per hour. To make things easier, let's go for 35 turns per hour. The watch holder takes around 3,5 seconds for one full turn when I put 9V on the motor leads. So, the motor needs to be on full power 122,5 seconds per hour. 2 mins per hour would be good enough. 1st hour clockwise, 2nd hour counterclockwise, 3rd hour clockwise and so on.
Paul_KD7HB:
Robin, I think he is writing about a "self winding" watch. It has a pendulum inside that winds a bit every time your arm swings about.
Jeez. He made it sound very complicated and scientific.
All he needs is something to shake it back and forth. Maybe make a miniature garden swing with a small servo or DC motor to swing it back and forth. Could be made into a very attractive ornament.
Robin2:
Jeez. He made it sound very complicated and scientific.
All he needs is something to shake it back and forth. Maybe make a miniature garden swing with a small servo or DC motor to swing it back and forth. Could be made into a very attractive ornament.
...R
Pardon my rudeness, but what is complicated and scientific about "I want a motor that makes 800 turn per day"?
Anyway, this is the watchwinder I'm talking about. I don't have to build it, because I already have it (it's quite old now). The PCB blew up (I think, the motor is fine). I want to replace it with an Arduino. That's all there's to it.
Manor_royal, thanks for the link. But all the 'getting started' pages start at software/programming. Before I get there, I need to know which wire to put on which input/output. Where do I put the +9V on the arduino? What output do I use for the motor driver breakout board? Which input do I use on the breakout board? Where does the breakout board gets it's 5V from? Which input on the arduino do i use for the two I/O switches.
jwswets:
Anyway, this is the watchwinder I'm talking about. I don't have to build it, because I already have it (it's quite old now). The PCB blew up (I think, the motor is fine). I want to replace it with an Arduino. That's all there's to it.
If you had posted that image at the start it might have short-circuited a lot of discussion.
If you mean that you want to get your existing winder working again how about posting some details about what is inside it.
I presume it won't matter if it does more than 800 revs in a day.
The wires have connectors on them (that conveniently fit the pins of the arduino as well).
The two I/O switches determine the turns per day (650/750/850/950). The I/O/II switch does the direction (clockwise/bidirectional/counterclockwise).
Mains powered, 9V
The motor is OK. Yesterday, I put 9V on it (using my benchtop power supply) and it ran perfectly.
The switches don't necessarily have to have the same function as before. The Arduino can take care of that. I'd rather have one I/O switch function as an start/stop switch. If I ever get a new watch which takes a different turns per day, I'll hook up the arduino to the computer.
jwswets:
The motor is OK. Yesterday, I put 9V on it (using my benchtop power supply) and it ran perfectly.
That is very useful to know.
When you did that test how fast was the watch winder turning?
Could you get a couple of AA alkaline cells in series and connect the 3v to the motor and see how fast the winder part turns?
Maybe also try a single AA cell (i.e. 1.5v).
The two I/O switches determine the turns per day (650/750/850/950). The I/O/II switch does the direction (clockwise/bidirectional/counterclockwise).
How much of that functionality do you require?
Another question - when the device was working properly did it do the 850 turns continuously - i.e. never stopping - or did it do one turn and then pause before doing the next turn?
At 9V the motor takes about 3.5 seconds per rotation (of the watch holder)
At 6V the motor takes about 5 seconds
At 3V the motor takes about 11 seconds
From the same post:
jwswets:
The switches don't necessarily have to have the same function as before. The Arduino can take care of that. I'd rather have one I/O switch function as an start/stop switch. If I ever get a new watch which takes a different turns per day, I'll hook up the arduino to the computer.
The device used to turn for some time (wasn't specified) and take 12/18/24 minutes rest. Then turn again. The rest period determined how many turns per day were made. For my goal the best would be 30 seconds 'on' every 15 minutes or 1 minute 'on' every half hour. Running on 9V that is.
If not the electronics between the Arduino and the motor can be simpler, or at least cheaper. If you want bi-directional control one of the Pololu DRV8833 motor drivers would be suitable. They seem to be more common than the slightly cheaper DRV8838 - which would also be suitable.
An Arduino program to turn a motor on for N seconds and off for M seconds will be very straightforward. Look at how any one of the LEDs is controlled in the demo Several Things at a Time. The intervals can easily be extended to the range you want.
