auto page turner prototype

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Re: auto page turner prototype

Postby dtic » 15 Jul 2010, 14:05

I'm still stuck on platen up/down movement automation. I basically lack the electronics skills needed and would need stepwise aid to pull it through (see arduino forum thread linked above). So, in a very sly move to draw attention and maybe help to this thread I hereby post a sample video of the current setup 8-) . As you can see I've switched from pushing the book page (friction) to pulling it (sticky tape suction). Both the long page pulling finger and the small side finger are powered and controlled by the Arduino microcontroller hooked to a laptop.
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Re: auto page turner prototype

Postby Gaaren-gaargle » 15 Jul 2010, 16:59

Looks very good! ;) When is the instruction ready? :lol:
What is it with the automation of the platen that is troubling you?
I have no engineer background, but what about a "bike pump" that gets filled with air and by that way levelling the platen up and down. Or a string on a wheel?
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Re: auto page turner prototype

Postby Mathue » 18 Jul 2010, 21:51

dtic wrote:As you can see I've switched from pushing the book page (friction) to pulling it (sticky tape suction). Both the long page pulling finger and the small side finger are powered and controlled by the Arduino microcontroller hooked to a laptop.


That's pretty cool dtic!
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Re: auto page turner prototype

Postby dtic » 04 Sep 2010, 08:12

I'm still stuck on the platen movement. Or rather I got stuck, tried several times to get unstuck and, failing that, have put the project on hold. This is completely due to my lack of electronics skills (and lack of time to aquire some), not because the project itself is extremely hard or complex. On the contrary, my hunch is that someone with skills in electronics would solve this easily.

Up to date overview: I have a PC-controlled Arduino board that controls small servo arms that turn pages in a book (see last video above for the latest setup). That already works fine. I've had it turn 50+ pages in a row without error. I now only need to control a stronger motor to move the platen up/down. Arduino can't power such a stronger motor by itself. External power is needed.

So I need: (1) a stronger motor (stepper motor), (2) a special circuit (h-bridge) acting as a middle man, (3) an external power supply, (4) arduino code to control that motor. I have two stepper motors. One lacks a data sheet so I've set that aside. The other is a 5 wire unipolar motor with detailed data sheets available. I have two salvaged external power supplies (18V and 30V). I have schematics for building a new h-bridge for the 5 wire motor. I have found code tutorials for controlling it all through arduino. But: I don't know what power supply will suit (as in not destroy) my other parts. I would need very specific advice on this point, i.e. I'd need someone who knows these things to take the data sheet info, do the math and give me a certain verdict. Like answering yes or no to this: "would the the external power supply labelled 18V, 1.1A be suitable for my 5 wire stepper motor (given the the unipolar h-bridge circuit, given the wires used, given the arduino board)?"
Here is the arduino forum thread with data sheets and other details: http://www.arduino.cc/cgi-bin/yabb2/YaB ... 9937/30#34
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Re: auto page turner prototype

Postby Tim » 05 Sep 2010, 13:08

My best suggestion would be to find your nearest Maker space and make a trip there after making contact and setting up some time that someone could help you learn what you need to know. Many/most have mailing lists, etc. The gist is there will be someone that will be able to show you what you need.
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Re: auto page turner prototype

Postby daniel_reetz » 05 Sep 2010, 13:21

First of all, I missed your new page turning demo progress video! Do you mind if I host it on Youtube again?

Second, I can answer those questions for you. And third, you can avoid those questions somewhat by buying a Motor Shield for your Arduino.
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Re: auto page turner prototype

Postby daniel_reetz » 05 Sep 2010, 13:23

Tell you what, I can mail you some more powerful stepper motors. I have a collection of some nice ones here with me.
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Re: auto page turner prototype

Postby daniel_reetz » 05 Sep 2010, 13:29

dtic wrote:"would the the external power supply labelled 18V, 1.1A be suitable for my 5 wire stepper motor (given the the unipolar h-bridge circuit, given the wires used, given the arduino board)?"
Here is the arduino forum thread with data sheets and other details: http://www.arduino.cc/cgi-bin/yabb2/YaB ... 9937/30#34


In this case, the answer is yes. The power supply is less than the maximum rated voltage of the stepper (24V). It is also below the maximum supply voltage for your SN754410NE H bridge, which maxes out at 36V (and at 36V, it runs so hot that it malfunctions, I can tell you from experience). The power supply, at 1A, has enough current to reasonably power a few small motors.
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Re: auto page turner prototype

Postby dtic » 05 Sep 2010, 14:12

Daniel: sorry I was unclear when writing "stronger". I just meant to say something with more power than the tiny servos I use for the other parts in the machine, which the stepper I have already has I think. So I'll first try to get that stepper up and running. But thanks a lot for the kind offer! (Also I'm in Europe so the shipping would cost a lot! I can likely salvage some other stepper if this one won't work out.) Motor shield: yeah, I got that suggestion in the arduino thread too. Problem is I'm not sure how to use that and at the same time control four small servo motors. I have the servos all set up with the arduino card already and so prefer some way to keep all that as is. But if there's some easy way around that problem then I'll definitely go for that option. It would be much more durable than the breadboard h-bridge circuit.

Youtube, sure go ahead! I declare it CC by-nc-sa.

Thanks for power supply feedback! But note that the h-bridge you commented on was one I put together for another (bipolar) stepper. I put that stepper on hold when I found no data sheet for it and so didn't know what power supply would work (and be safe). So I now focus on the other stepper. It has five wires which I think indicates that it is unipolar. Then I need to make and use another h-bridge for it. The "Unipolar stepper two-wire circuit" schematic says I need a ULN2003 or ULN2004 chip for that; I just want to first flesh out if the other parts (5-wire stepper, power supply) will fit with it before ordering the chip.
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Re: auto page turner prototype

Postby daniel_reetz » 05 Sep 2010, 16:21

I really don't mind throwing together a box of parts to support your research. Let me see what I have laying around...
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