First Post! L298 and L297 driver question...

Hi All

I am very excited to be working with Arduino and seeing what I can come up with! My first project is to build a small desktop CNC using the Arduino Uno and L298 Stepper Drivers with NEMA 17s. I have a background in electronics from college however I pursued a career in programming. My electronics knowledge is basic but improving daily.

This is the L298 I purchased;

I discovered that there is no way to connect the three L298 drivers to the UNO and that the L298s need an L297 connected between the Arduino and the L298. After a couple of frustrating days on google, I have not found a good example for me to follow regarding this kind of setup. Is there a tutorial on this subject that anyone could provide or some guidance would be greatly appreciated.

Thanks in advance!

This is an example of the setup that is similar to mine except he uses a custom made board to interface between the Arduino and L298s which suggests an alternative to the L297;

Hello, welcome to the forum.

Don’t understand your comment: “I discovered that there is no way to connect the three L298 drivers to the UNO”.
I see plenty of pins on the board.
You may need to connect some up in parallel.
For example, INT1,2,3,4 all in parallel (all 1s, all 2s, all 3s, all 4s) then to 4 Uno pins.
Provide seperate Enable pins to each board, and only move 1 stepper at a time.

Can’t suggest a tutorial - I find it better to read the datasheet and go from there.

L298N.pdf (599 KB)

I discovered that there is no way to connect the three L298 drivers to the UNO

By definition you can not discover something that is not true.

and that the L298s need an L297 connected between the Arduino and the L298.

Wrong again. The L297 is a chip that works with the L298 to make it into a chopping regulator. With the right supply and motors it is not needed to control a stepping motor.

The L298 can be used to drive stepper motors but they are really meant for regular DC motors and a proper stepper motor driver board such as the Pololu A4988 would be much easier to work with and they allow the steppers to be driven at higher voltages for better high speed torque.

Whichever way you are driving your stepper make sure it has its own power supply. The Arduino can't supply enough current for a motor.

...R

CrossRoads:
Hello, welcome to the forum.

Don’t understand your comment: “I discovered that there is no way to connect the three L298 drivers to the UNO”.
I see plenty of pins on the board.
You may need to connect some up in parallel.
For example, INT1,2,3,4 all in parallel (all 1s, all 2s, all 3s, all 4s) then to 4 Uno pins.
Provide seperate Enable pins to each board, and only move 1 stepper at a time.

Can’t suggest a tutorial - I find it better to read the datasheet and go from there.

I may be very well wrong on that statement. I couldn’t find examples of how to connect three L298 driver boards directly to the UNO. The example in the video on my second post was the only one I could find and it had a custom board between the UNO and driver boards. My preference would be that all the motors would run simultaneously unless there is no real advantage in going with that approach.

Grumpy_Mike:

I discovered that there is no way to connect the three L298 drivers to the UNO

By definition you can not discover something that is not true.

and that the L298s need an L297 connected between the Arduino and the L298.

Wrong again. The L297 is a chip that works with the L298 to make it into a chopping regulator. With the right supply and motors it is not needed to control a stepping motor.

I appreciate your response. I am on a tight budget and being true to the noob, I chose the items I have believing they would suffice. I would like to make it work with what I have. Any advice along those lines?

Robin2:
The L298 can be used to drive stepper motors but they are really meant for regular DC motors and a proper stepper motor driver board such as the Pololu A4988 would be much easier to work with and they allow the steppers to be driven at higher voltages for better high speed torque.

Whichever way you are driving your stepper make sure it has its own power supply. The Arduino can't supply enough current for a motor.

...R

I have built a couple of ATX power supplies just for this purpose :slight_smile:
One of them converted to a soldering station/power supply and the other strictly for powering the motors.

I will look into the Pololu A4988 for future reference. Thanks!

As a search through the forum will reveal, many people have run into the problem that the L298 driver is not capable of driving their motors. Do you have the winding voltage and current limits, or can you post a link to the motor datasheet?

I decided to purchase the Mega 2560 because it has all the IO pins I need to accomplish the task.

Thanks for the suggestions and have a great day!