Can anybody tell me the pros and cons between the
pololu.com/catalog/product/1376
and
pololu.com/catalog/product/755
Can both move an actuator in both directions? I know I am probably going to end up using limit switches now. I recently had the one without the usb port on it, but it died. Now, I am just wondering if I should try to use the same one again or if I should upgrade a little bit to the new one? Any help on this subject will be greatly appreciated. Thank you!
Hello.
First off, we call one a driver, and one a controller, and we describe the basic distinction here:
(This distinction is not something universal everyone agrees with, but we think it’s helpful in classifying two fairly different groups of products.)
In general, the controller is the far more advanced product, and unless there is something specific you want to do with your motor that the controller does not support, the controller is probably the way to go. For instance, the new simple motor controllers can connect directly to a computer USB port or several other higher-level interfaces. On the other hand, if you want some particular response to some kind of error condition that our controller does not happen to offer, you have to make the system yourself, for which you could use just the driver (though you could do it with the controller, too, just that using the whole controller might be overkill).
- Jan
I was planning on interfacing the motor driver with an Arduino Duemilanove. If I used the motor controller, could i hook up a rotary encoder directly to the controller and cut out the Arduino? Also, I just need it to make the actuator extend and retract which I am assuming the controller does as well as the driver? I am so new to all of this (as I am sure is obvious haha) and I really appreciate all of the help I have received from this forum.
We do not have any motor controllers that handle quadrature encoders (yet), so you still have to use your Arduino for that part. What do you mean by “does as well”? The point is that in terms of power handling, they are about the same, but the interfaces are different. With the controller, you can set up things like acceleration ahead of time, and then just send a single serial command that says, “go at some speed”, whereas with the drier, you have to keep generating the PWM, and if you want things like acceleration, you have to implement that all yourself. If you don’t really know what you’re doing, I think the controller is the more appropriate product for you.
- Jan
I meant that the driver can control the direction the motor turns to extend and retract the actuator. The controller can do this too correct? Also, should there be any issues hooking either to an Autocraft Silver 12V battery? I don’t think there should be, but the Pololu 18v15 driver I was using yesterday worked twice then died.
Battery Specifications:
shop.advanceautoparts.com/webapp … fragment-2
Yes, the controller can do that, too. The controller is the driver plus extra stuff, and we would not give up something as fundamental as being able to go in both directions. The only thing you potentially lose with the controller is very small details of the operation that probably don’t matter in most applications. The battery should be fine, though you could consider putting a fuse in line with the motor controller or driver.
- Jan
So the motor driver and battery shouldn’t have any issues? I was working with the motor driver yesterday and it worked fine the first two time I used it. After that the 5V(out) stopped emitting a voltage and the driver wouldn’t work anymore. This is why I am somewhat paranoid on hooking my other one up before I am sure. I am going to buy some fuses tonight to help safeguard the driver. This next question is kind of off topic, but you are very knowable on the subject.
The way I had it set up yesterday was:
V+ to the positive post on the 12V battery
OutA and OutB to the actuator
GND to the negative post on the 12V battery
GND to ground on my breadboard
PWM to the 5V(out) on the breadboard
This configuration worked.
When I put a wire from Dir to ground to make the actuator extend (switch directions) is when the driver stopped working.
The driver and battery should be fine, and your setup on its own sounds okay. Based on what you’ve said, it’s difficult to know exactly why your driver died. (There’s a lot of ways you can break things like this.) The controller should be a bit better in the sense that it gives you more feedback (e.g. over USB) about what is going on, but on the other hand, there’s also more on there that can be broken.
- Jan
Hello.
As Jan says, it’s difficult to tell from what you’ve written what could have gone wrong, but my guess is that you accidentally connected either PWM or DIR to the VIN output that is right next to the 5V output. Doing this would most likely destroy the board. Very rapid direction changes could also be bad for the board if you have a large motor connected, but your actuator does not sound like it big enough to cause this kind of problem.
Also, the Simple Motor Controller has built in support for limit switches, which could come in handy with your actuator.
- Ben
That’s kind of what I am thinking happened as well. Can you use a potentiometer that is compatible with the motor controller with the actuator? I’ve only seen them used with servos. Just curious
I’'m not sure I understand what you’re asking. By “motor controller”, do you mean the jrk or the Simple Motor Controller? And “use a potentiometer”, do you mean as position feedback for closed-loop control?
- Ben
Will a rotary potentiometer similar to this:
alibaba.com/product-gs/29841 … meter.html
used with this motor controller:
pololu.com/catalog/product/1376
work with a linear actuator?
The rotary potentiometer will be used to control the length (position) the actuator is extended.
You can use an analog voltage input (such as a potentiometer) as a speed-control input for the Simple Motor Controller.
You will not be able to control the position of the actuator without closed-loop feedback from the actuator itself, and you will have to close the loop yourself (using something like an Arduino). In this scenario, you would have the Arduino read your position-control potentiometer and send the appropriate commands to the Simple Motor Controller based on the requested position and the position feedback it gets from the actuator.
- Ben
Ok. I about to order. Would you suggest the 18v15 motor driver or the 18v25 motor driver? It’s just the actuator, motor driver, arduino, and the battery in the system. The 18v15 should work from everything that I have heard, but I will only have time to order 1 more driver haha
The 18v15 (or 24v12) should be totally sufficient, but if you think you might want to do higher-power motor control at some point in the future, you could get the 18v25 or 24v23 now and reuse it later on. Don’t forget that you will need a USB A to mini-B cable to connect it to a computer (the controller settings can only be changed using USB).
- Ben
Aight. I’m going to go with the 18v15 motor driver. I got the 18v15 motor controller in the mail saturday. I am ordering this motor driver as a back up in case I have another problem. I really like what i’ve read about the controllers. I have ordered some female-male wires so I can use it. Thank you for all the support and help!
