Stepper Motors with Arduino - Controlling Bipolar & Unipolar stepper motors

Hi every one,

I am not very good at using a forum.  My question is how can I add a reverse switch to this sketch.  Also how would I know if some one have replied and where can I see the response.

Thanks every one

As usual... another excellent lecture.  One thing though, the professor didn't notice my raised hand. 🖐️ 😉 

I'm starting my background understanding research for my project and have two three five(ok...) eight questions.  They reproduce if I have too much time on my hands.

1. (38:20) About the 100 μF capacitor.  Is this used because of the A4988 specifically, or drivers in general, or something else in general?  
2. Can someone explain its purpose in air-head* terms?
3. I'm going to be using TMC2209 Trinamic drivers.  Do I need to use the capacitor?
4. And if all drivers need it, why don't they just put it on the boards?
5. If I use the Serial interface instead of the pulse method, does that make a difference?
6. (46:30) About tuning the A4988 for maximum current capability of the stepper motor.  BTW - When I needed to tune a couple of A4988's in the past, all I found were the voltage-calculate-trust method videos.  This was a breath of fresh air that makes far more intuitive sense to me.
7. I understand that the TMC2209 can adjust this maximum current setting via coding and the Serial interface.  I also am lead to believe that I can get the current (time) value of the current (I=V/r) via coding and the Serial interface.  Can I punt using the volt meter and do a set/read loop and calibrate it via the Sketch?
8. Will the TMC2209 driver keep this setting non-volatile?  Or... do I need to either store this setting OR perform the calibration on Sketch boot?

I think... that will cover the Inquisition... for now.

* derogatory term used on college engineering campus to identify Aerospace Engineers.  I'm better now, my hair turned grey.

@azflyer Subscribe will get you an email notification

Posted by: @inq

As usual... another excellent lecture.  One thing though, the professor didn't notice my raised hand. 🖐️ 😉 

I'm starting my background understanding research for my project and have two three five(ok...) eight questions.  They reproduce if I have too much time on my hands.

If you take off your wrist watch you won't have time on your hands and more 🙂

1. (38:20) About the 100 μF capacitor.  Is this used because of the A4988 specifically, or drivers in general, or something else in general?  

c) something in general

1. Can someone explain its purpose in air-head* terms?

I'll try. Its purpose is to store some charge locally so that if whatever is driving the driver gets busy and voltage drops, the capacitor becomes a local supply to stabilize the power and keep the driver going.

1. I'm going to be using TMC2209 Trinamic drivers.  Do I need to use the capacitor?

It's safer to use one, but it depends on your circuit(s).

1. And if all drivers need it, why don't they just put it on the boards?

Because the manufacturers have cut back on crystal balls for economic reasons. They don't know how likely it is that your project will be overloaded or stressed to the point where a capacitor is required, nor to the extent possible. So they leave that to you. Besides it'd cost them another $.02 to add it in 🙂

Sorry, I don't know anything about TMC2209s so I can't answer the rest of the questions you've posed.

I think... that will cover the Inquisition... for now.

I have to confess that I wasn't expecting the Spanish Inquisition 🙂 🙂

@will You were expecting some other inquisition?

@zander 

Nobody expects the Spanish Inquisition (It's from old Monty Python shows 🙂

@will Yes, another reminder of how slow and old my brain is getting. BIG fan, have most of their DVD's if not all. Also have Faulty Towers, and at one time had a towel and room key.

This video is fanstastic, and so well put together. Thank you. IN the video there is a demonstration on ULN2003 and having two steppers perform rotations at different speeds and in different directions. I would like to perform the same with 2 NEMA 17's and A4988's. Any resources for something like this?

@carlmanx

The following link will hopefully complement the dronebot video and it does show the A4988.

https://howtomechatronics.com/tutorials/arduino/stepper-motors-and-arduino-the-ultimate-guide/

@byron Thank you Thank you Thank you!

Posted by: @byron

@carlmanx

The following link will hopefully complement the dronebot video and it does show the A4988.

https://howtomechatronics.com/tutorials/arduino/stepper-motors-and-arduino-the-ultimate-guide/

I noticed it had a TMC driver mentioned, but didn't go into any details.  

Posted by: @inq

I noticed it had a TMC driver mentioned, but didn't go into any details.  

You didn't keep your finger on the scroll down bar long enough then 😎  The last part of the article shows using the TMC2208 driver.  He also comments its a better driver than the other 2 but this comes with a bigger price tag.

Posted by: @byron

Posted by: @inq

I noticed it had a TMC driver mentioned, but didn't go into any details.  

You didn't keep your finger on the scroll down bar long enough then 😎  The last part of the article shows using the TMC2208 driver.  He also comments its a better driver than the other 2 but this comes with a bigger price tag.

I agree it is a good companion article to Bill's video with some good details on the fundamentals.  I failed to be specific 😉.  I was looking for using ESP/Arduino with the Serial communications interface and even more specifically, I want to be able to get the feedback... 

StallGuard, CoolStep