Steppers Not Stepping

I have finally gotten the computer program working with my electronics, and have gotten the extruder exerciser running. My steppers will run with the stepper tester, but not with the stepper exerciser in the program or in build processes. I know that in the arduino program, my step and dir pins are in the correct places. Where do the other wires go? Or is there another error? Also, I think I burned out my L298 chip when soldering it because the stepper tester will not make it work. Only one of the two red/green lights turn on. Is there any way to know wether it is broken?

Congrats on getting it working, at least partially!

Sorry, which electronics, and which stepper tester are you using? I'm going to assume you're using the single Arduino gen 2 version.

I didn't have much luck with the stepper exerciser in the Java host software on the 0.6 RepRap DVD. A good test would be to use the "poke" debug utility if you're using the Snap protocol; personally, I had better luck sending gcodes manually to the gcode firmware using the Arduino serial monitor programs. The Gcode version is a bit trickier to set up though. The trick is to minimize the number of things you're testing at once - it's hard to tell if you've got a communications problem, a wiring problem, or a burned out chip.

As for wiring, the schematic is here:
[reprap.org]

Nevermind the valve part. I used only the Min opto switches, so that left me with 4 wires per stepper driver board - step, direction, min, and ground. Plus the power connections, and the stepper and opto switch connections themselves, but those are on the output side of things.

If you're got the jumper set to half stepping, then you'll only get one light lit during some positions, but as you move the stepper, of course the rest of the lights should light up in the proper sequence. My stepper drivers seem to usually boot up with both lights green, but that could be just me.

Wade

I am using Generation Two Single Arduino. Where does the ground wire from the stepper drivers go to? Also, in the program's global preferences menu, I noticed ZAxisAddress, XAxisAddress, and YAxisAddress. What are those?

Thanks,

Jajo

The ground wire goes to ground. Anywhere should work, but you have to be careful of ground loops. The short and simple answer is to simply ground your Arduino to the RepRap power supply ground, and that will ground your stepper board drivers as well.

Simply connecting one of the ground wires on one of the steppers should do it; but it's probably better to connect up each stepper ground wire to the Arduino ground, in case you happen to unplug your only grounded stepper.

I had some large transient voltages between my laptop's USB Ground (which the Arduino is connected to) and the power supply ground; make sure the chassis of your host computer is well grounded as well to prevent that.

I'm not familiar with those address preferences; google turns up:

[www.google.com]

Looks like either a board address or the pin #.

Wade


Wade

jajo Wrote:
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> I am using Generation Two Single Arduino. Where
> does the ground wire from the stepper drivers go
> to? Also, in the program's global preferences
> menu, I noticed ZAxisAddress, XAxisAddress, and
> YAxisAddress. What are those?

If I recall correctly the old PIC electronics used a token-ring-like network between the various boards and each stepper controller, therefore, had a "network address". Perhaps the software is intended for old PIC electronics and not the Single Arduino electronics.

I connected all of my boards- the stepper controllers, dc motor driver, and pwm driver- all to the arduino ground pin. Is this enough? Also, if I am using my Z-Axis board (that has a burnt out L298 chip) as the master, will the X and Y run still?

That should do it. Check the grounds on your computer, just to be sure though - take your multimeter, set it to DC volts, and measure the difference between the Arduino ground and your computer chassis - anywhere metal should work. Then do the same thing with the multimeter set to AC Volts. You should get a reading close to 0 Volts, but it's good to check. I had 48 V AC at one point, due to an ungrounded laptop power supply, and it was causing all sorts of odd RepRap behavior.

The different axis should still run fine; I think the Arduino slave/master stuff just sets the PWM modulation on the stepper current control so that they're all pulsing in sync. It doesn't matter much at all, but it can help reduce the electrical noise if you're having problems with it. You can run any axis completely independently though, I often run without the Z axis when I'm testing other stuff.

Also, when you're routing the wiring, try to keep the stepper motor leads separate from the digital input lines (step and dir). I was getting some feedback on my X axis when I first built my machine; the X axis would start stepping all by itself. I traced it down to running the X axis step wire unshielded right next to the Y axis motor lead for about 6 inches; the chopped AC signal on the motor lead was feeding back into the input.

Hope that helps!

Wade