Help with arduino and stepper motor.


after several tries and failures with Arduino (uno) and SN754410 in stepper driving, I prefere to ask your opinon about my next Arduino based stepper controller. (In fact, I didn't use flyback diodes with SN754410 and I think that is why I burnt my arduino.).

So here what I am planning to do:

More details about Stepper controller:

More details about MAX232:

What do you think ?

Thank you for your help


Edit: added relay board in order to control Dremel Tool ( More info about relay board: ) and Enable command

Sorry, I was too fast with my first answer. I have deleted it. :-[

Do you have a link to the L297 board?

The ground on the ATX supply needs to be connected to the ground on your arduino:-

Thank you for your answer

You're right, I forgot the arduino ground in my schema. Unless this point, is there any other problem ? (switch sensor ?)

(here is the link to the L297 board (in french sorry) )

I am puzzled by the first driver's +5v going to the Arduino. Obviously you didn't meant that. The rest looks just fine.

Can I ask how are planning to control the Drivers? Are you using the Arduino to pass information from your PC to the drivers or are you planning a stand alone application with Arduino?

In fact, Stepper driver controllers have a +5v regulator. But I could have wired directly the +12v of the ATX supply...

I use a stand alone application in Arduino ( CNC machine ) based on the reprap project.

I use a stand alone application in Arduino ( CNC machine ) based on the reprap project.

So let me get this straight. Are you using a RepRap-like application to send G-Code from a computer (like RepRap does), or are you building a 100% stand alone application on Arduino that doesn't needs an external computer?

If the last, please let me know how is working for you. I am on the process of making exactly that, controlling 3 steppers at the same time with one Arduino.

I am not using G-Code at all, just a low level of stepping control. I got stuck when I add LCD's to the equation and everything fall apart, but thanks to the forum I am on the process to fix that.

Edit: I just noticed that your stepper driver looks like too much for yours 4.7W motors. You might be on better shape with an EsyDriver for that small motor or use bigger motors for those drivers.

Yes you're right, I will send G-code over the serial port. I have thought about adding SD card in order to avoid using external computer... But the serial link, in my case, gives me more flexibility.

I know that my controllers are a little bit oversized but I want to build a bigger CNC machine next and don't want to buy others controllers...