I have a clone Uno R3, which is surely working perfect. I have two DRV8825 drivers and a CNC shield v3.0. I installed the 0.9j GRBL on the UNO and set up everything. Connected the motor to the shield with A1A2B1B2 and A1B1A2B2 connections.
It doesn't seem to work. It doesn't even make a noise or something from the motor.
The motor is a nema23 stepper rated at 2.8A (which I know is more than the max from the DRVs). I wanted to try it out so I connected only one stepper to the shield with only one driver, and I used a PSU which is rated at 24V 1A.
I know it's not the best, but I figured it would suffice for trying things out.
What can be the cause of the problem?
I tried GRBL controller and Universal g-code Sender, they didn't work.
so let's start again.
Could you pls show your complete wiring incl. The pins of the uno which you use.
Did you wire the uno with the drv8825 before and tested this with your stepper(s) with a simple code (I think, in your first thread Robin2 gave you some examples/links)?
Hi rpt007,
Yes, I tested it, and it worked, but with a smaller motor.
What kind of wiring do you mean? I slided the shield into the arduino, because it fits on it. All the wiring is seen on the picture. Or did I miss something?
Southpark:
I see. So you're saying that this stepper motor uses a current that is more than the rated maximum source current of this driver.
This means you answered your own question to your problem. Nicely done!
Yea, I think no. Even if the current is less, it should at least make some noise or something. But it doesn't even shudder or something. I mean the motor.
Or it is really the reason?
Maybe you can test your stepper driver. Like..... remove the stepper motor. Then set the current limit of the DRV8825 to some relatively small amount of current. Then connect an ammeter across a terminal pair (of the DRV8825), then fire up the stepping software to simulate 1 step. And see if you get some activity (ie. current). This is to see if the driver system is at least working to start with.
Yes, I wrote that I'll use tb drivers and a decent psu, this was just a test if they would work. They didn't. I mean, the drv drivers and the motors. I said in that thread, that I got the sec drivers for free. That's whyI'm trying them, and that's why I haven't bought the tb drivers yet.
In the time I have been contributing to this Forum it seems a good rule of thumb that if a problem is not substantially solved by Page 2 of a Thread it will never be solved.
norbert1998:
Do you mean a pair of wires that go to the motor?
Yes.... that's right. If the system isn't functioning in the way we expect, then it's time to start focusing on particular sections of it.... such as the software and driver..... followed by the motor.
If the driver is outputting the correct current (signals), then focus on the motor. Even for a NEMA 23, you expect it to at least do something....like move a little bit.
Use a multimeter to measure the winding resistances.... make sure you have the windings connected to the driver correctly. The NEMA 23 will likely have colour coded terminals...... and specifications will probably tell you which terminal is A+, which is A-....and B and B- etc. So you would then get your multimeter to see if a resistance measurement across the specified terminals will give a sensible resistance reading. If it does give a sensible reading, then you can be reasonably confident that you know which terminals are which.
Southpark:
Maybe you can test your stepper driver. Like..... remove the stepper motor. Then set the current limit of the DRV8825 to some relatively small amount of current. Then connect an ammeter across a terminal pair (of the DRV8825), then fire up the stepping software to simulate 1 step. And see if you get some activity (ie. current). This is to see if the driver system is at least working to start with.
Never ever do this, it may fry the driver. Place the meter in series with the motor winding, the
driver requires a strongly inductive load.
MarkT:
Never ever do this, it may fry the driver. Place the meter in series with the motor winding, the
driver requires a strongly inductive load.
Not when the current limiting is adequate. Sure......after making sure we measure the coil winding (to ensure we got a coil there), we can then connect a meter in series with a coil.
Do you have another stepper motor that can be comfortably powered by the DRV8825?
If so, concentrate on getting that working with a short simple program Simple Stepper Code and the Pololu DRV8825 wiring diagram.
When that works switch everything off and swap to the other bigger motor. Then if it does not work you will know that there is no problem with the program and that you need a driver that is powerful enough for the bigger motor.
Well, I was able to try it out, because I found the problem, which was so stupid I didn't even try to check it.
After burning the first DRV8825*, a was sure, that the power input was right, so when I found out why did the first DRV burn, I tried it again, but there was nothing happening. Today, it turned out that indeed the power input was the problem. The 1A one made the motor shudder.
Later I tried to get things worked with a 24V 3A PSU, which caused stupid shudderings and only gave 0.5-1A at max to one winding. Even with that 0.5-1A, the driver was HOT. So, I'll sell the working two and the shield and buy the TB6600.
Thanks for your help, again
*Seller made a picture of the CNC shield with the DRV8825s, but they were in the wrong direction so the (fortunately only) one I put in to try out released its fuel (the smoke).
norbert1998:
Well, I was able to try it out, because I found the problem, which was so stupid I didn't even try to check it.
That's ok. Good work. It is important to test each part of the system ...... like start from the beginning.... software and driver first - to make sure they are behaving in the expected way.
