DQ542 Drivers

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Kyo
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DQ542 Drivers

Post by Kyo » Thu Jun 23, 2016 11:19 pm

I see some folks have been using external drivers and some have had a few problems with wiring and such. I am using a DQ542MA Driver for this example ( what I have on hand ).

You have two options depending if you want to edit your settings to change the default behavior of grbl. By default grbl provides a active low signal to enable stepper and a active high to disable stepper. This is reversed from what the dq542ma drivers want to get. They need a active high to enable not active low. In that case we do not use the enable pin from grbl and instead use a 5v output.

Image

Demo video with this wiring:
http://www.youtube.com/watch?v=rpTDKAhMuqs

Now if you dont mind editing your grbl settings you can change the $4=0 setting to $4=1 doing this will change the grbl enable pin to provide the active high to enable stepper signal the dq542ma driver wants to see. Doing this we would use the enable pin from the arduino.

Image

Demo video with this wiring:
http://www.youtube.com/watch?v=GthtTrkQ0_A


I have a single 5v 2amp power supply running the Raspberry pi / Protoneer hat / Nano v3 combo.. I am running the bCNC g-code sender software on the pi. The Driver is hooked up to my 24v mean well power supply.

I hope this is of some help to everyone. I am really enjoying using the v2.51 hat It has been a rock solid performer. I am excited about the updates and changes the v2.58 hat brings. I look forward to trying one of them out.

Perhaps a v3 board with all the updates and benefits that the v2.58 board has but remove the option for pololu drivers. Instead have screw terminals (5v,gnd,enable,step,dir) for each axis broken out so you can hook up external drivers to there own screw terminals on the board. I know offering two boards might be a pain. but a simple version of the board just for external drivers would be sweet!

EDIT: updated images to host on my website. Looks like they only showed if logged in to the openbuilds forum. ( original host location )
Last edited by Kyo on Mon Nov 21, 2016 12:08 am, edited 2 times in total.

Bertus Kruger
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Re: DQ542 Drivers

Post by Bertus Kruger » Tue Jun 28, 2016 5:28 am

Thanks for the information!!!

The GRBL enable pin that is active low point is major point.... ;)

Kyo
Posts: 15
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Re: DQ542 Drivers

Post by Kyo » Tue Jun 28, 2016 5:48 am

No problem, happy to share. :D

Levictus
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Joined: Mon May 30, 2016 5:15 pm

Re: DQ542 Drivers

Post by Levictus » Sat Nov 19, 2016 2:31 pm

Hi Kyo
Thanks for this. I am also using the DQ542MA drivers, v2.58 RPi CNC board, and the new external driver add on boards to breakout the pins. Do I still need to change the GRBL setting $4=0 to $4=1 ? I tried it both settings and seems to function both ways. Thanks again...

Bertus Kruger
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Re: DQ542 Drivers

Post by Bertus Kruger » Mon Nov 21, 2016 12:02 am

Levictus wrote:Hi Kyo
Thanks for this. I am also using the DQ542MA drivers, v2.58 RPi CNC board, and the new external driver add on boards to breakout the pins. Do I still need to change the GRBL setting $4=0 to $4=1 ? I tried it both settings and seems to function both ways. Thanks again...
That's interesting. If that is the case it might be that your steppers are enabled at all time... ??

Kyo
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Joined: Sun Apr 03, 2016 4:15 am

Re: DQ542 Drivers

Post by Kyo » Mon Nov 21, 2016 12:15 am

Updated images to host on my website for the original post. Looks like OB prevents viewing images when not logged in now.

hmm, I had to update the setting depending on how I wired it. Which method above did you use to wire the drivers? No error led on the driver ( red led ) I agree it sounds like the drivers are enabled already. If it is working for you with out changing the setting. Don't worry about changing it.

Levictus
Posts: 9
Joined: Mon May 30, 2016 5:15 pm

Re: DQ542 Drivers

Post by Levictus » Tue Nov 22, 2016 2:15 am

You guys are both correct. I have my GRBL setting for step idle delay, msec as $1=255 which is always on. My machine is an OX CNC from Openbuilds. Seems to be a recommended setting in the OX forum... Its been working well!

Levictus
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Re: DQ542 Drivers

Post by Levictus » Tue Nov 22, 2016 2:16 am

And PS Kyo, I have the drivers wired like the second photo...

Ernesto2
Posts: 46
Joined: Sun May 06, 2018 7:17 am

Re: DQ542 Drivers

Post by Ernesto2 » Tue May 08, 2018 2:09 am

Sorry to revive an old thread but I haven't found an answer here.

I noticed that in your first pic, the protoneer shield is sending out negative step and dir signals with the 5v+ wired to the positives of the stepper controller, then in the next pic, it seems like the protoneer's step/dir outputs changed to high along with the $4=1 change that inverts the enable signal. I understand the inversion of the enable signal thing but not why the step/dir outputs changed polarity as well. Aren't the $2 and $3 options dedicated to inverting those signals?

My protoneer v2.58 outputs positive signals for step/dir, and I need them to be low active like in the first pic here. My TB6600 drivers run fine without anything hooked to either enable pin. Do I need to alter the circuit on the protoneer in any way to use the negative step/dir settings? Pull up/down resistors?

Bertus Kruger
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Re: DQ542 Drivers

Post by Bertus Kruger » Thu May 10, 2018 8:53 pm

Ernesto2 wrote:
Tue May 08, 2018 2:09 am
Sorry to revive an old thread but I haven't found an answer here.

I noticed that in your first pic, the protoneer shield is sending out negative step and dir signals with the 5v+ wired to the positives of the stepper controller, then in the next pic, it seems like the protoneer's step/dir outputs changed to high along with the $4=1 change that inverts the enable signal. I understand the inversion of the enable signal thing but not why the step/dir outputs changed polarity as well. Aren't the $2 and $3 options dedicated to inverting those signals?

My protoneer v2.58 outputs positive signals for step/dir, and I need them to be low active like in the first pic here. My TB6600 drivers run fine without anything hooked to either enable pin. Do I need to alter the circuit on the protoneer in any way to use the negative step/dir settings? Pull up/down resistors?
My feeling is that you don't need to use inversion setting in GRBL. The step signal does not care about high or low. It is looking for a change in state. So keeping it high or low does not matter.

The Direction pin on the other hand is looking at the state of the pin. If its high it goes in one direction and when low the other direction. When you hook up your setup check if the motors are moving in the desired direction. If not just change one of the stepper coil cables around. (Say A+ and A-)

That way you don't need to make any changes to GRBL. And the stepper driver only needs a Gnd , Step , Dir and Enable cable.

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