Adafruit vs L298 ?

Projects General Guidance
1

Hi

This is my first post in this forum. I actually have a project that seems feasible with Adruino (as far as I've seen):

I need to build a device with:

  • A Stepper Motor: The goal is to have a precise control of the max speed, a precise feedback of the number of rotations done, and programming some ramps in and out for it to start and stop on a very smooth manner.
  • A LCD display + buttons : Associated with a couple of buttons to navigate in a custom menu. Allows to set the number of rotations of a sequence, max speed of the motor and ramps timing.
  • A Buzzer : It will indicate when the rotation sequence is finished
  • A main push button : 1 short push to start/pause the sequence, a long push to reset the sequence in case we don't want to complete the full number of rotations.

First of all, is this device can be made with an Adruino Uno card?

As for the stteper motor control, is it simpler to use Adafruit (Adafruit Motor/Stepper/Servo Shield for Arduino kit [v1.2] : ID 81 : $19.50 : Adafruit Industries, Unique & fun DIY electronics and kits) or a L298 (like I've seen here : L298 Motor Control | Arduino Tutorial - YouTube)?

Thanks for your advices experts !

2

Yes, it can be made with an Arduino Uno.

I have never seen bad code by Adafruit, so you could use that shield with its library.
The Adafruit Motor Shield uses old components (no problem at all) and many pins (inconvenient).

The L298 is used by the Arduino Motor Shield.

I think the 'Stepper' library can be used with it.

The Stepper library is included with the Arduino software.

You could also use something like this, EasyDriver - Stepper Motor Driver - ROB-12779 - SparkFun Electronics

If you want to go cheap, a clone of the Adafruit Motor Shield can be found on Ebay for a few dollars.

You could use a I2C lcd with combined buttons, like this one:

Even a clone of the I2C LCD with buttons can be bought on Ebay.

3

Thanks for your feedback Erdin !

Are these cheaper clones reliable? I have seen some warning for these low price items on other forums.

4

They have the cheapest availabe components. So you might have to repair something.
I use the cheap clones to try, to test and to learn.

5

Try pololu.com (or eBay) for their "A4988" stepper driver. This has a two pin "step" and "direction" interface (toggle "step" high to make it take a step and setting "direction" high or low makes it go forward or reverse). It's altogether a superior driver compared to the L298-based boards; it has current control, it's more efficient (cooler), has overheat protection, short circuit protection, etc.

The AccelStepper library is more advanced than the Stepper library. The AccelStepper library allows an acceleration rate which allows you to more reliably ramp up to speed (steppers don't like to be thrown into full speed from a standstill).

Remember that telling a stepper to move never guarantees that it actually moved. In cases where it's overloaded or physically stopped you have no way to know if it moved or not. If it's important that you guarantee that the motor has moved as commanded then you need to add an encoder for that "precise feedback" you described. Try the AMT 100 series encoders for an option here; they start around $25 at digikey.com.

6

Thanks Chagrin

I'll order these parts and try to play with it for a while - not so expensive for things we can achieve with it !

7

These are exactly the combination I need. does anyone know what motor and display are these?

By the way, can a stepper motor run fast as well?

Thanx

8

The display is a clone of Liudr's Phi Shield. The particular clone in the video is made by DFRobot(.com).

The motor is a NEMA 17 size bipolar stepper motor. I'm going to go out on a limb and suggest they bought it at pololu.com with the driver.

Stepper motors are capable of a few hundred RPMs, but as you increase the speed of the motor you also lose a lot of torque. Depends on a lot of factors as to how fast you can go, but if you're looking to see them in action look for videos of RepRaps or Makerbots which are driven by similarly-sized steppers.