I just assembled the Protoneer CNC Shield V3.03 and installed some A4988 stepper drivers on it.
The documentation on the site is a bit limited, but the assembly was easy enough. The Protoneer site also has great directions on how to get the GRBL (G code driver) sketch into the Uno. However, I have a problem....
I hook up a driver and stepper to the X-axis and powered on the shield. No smoke, but no whirling stepper either. Regardless of what G code command I try I get no movement, but the IDE terminal does echo back "ok" after a valid command. I have verified that the ENABLE lines on the A4988 align with the correct place on the CNC Shield.
There is no documentation that I can find to offer help. I am wondering if I need to install any jumpers to enable the steppers. There are several headers that look like they could be for a jumper, but they could also be for an indicator LED. Without documentation, I can't tell and I don't want to smoke the sheild or a driver. My questions:
Is there any good documentation on the Protoneer CNC Shield V3.03 pins?
Do I need to jumper any of the headers pins to make the Protoneer CNC Shield V3.03 work?
Since I have looked for documentation, I will ask what the following Protoneer CNC Shield V3.03 connections do. Each have two header pins:
EN/GND (is this a safety lockout maybe?)
X.STEP/DIR (do the .STEP header provide power for an indicator LED?)
Assume no one knows what you're talking about (which is true for me), and offer links to information you have (or do you like us to do a lot of research you already did yourself ?)
Your list of those header pins is confusing.
I guess you mean first pin of one says EN, and that of the other header says GND ?
EN means ENable.
If it has a line over it, an exclamation mark in front of it (e.g. !EN), nEN or an asterisk that would mean it is active low.
Those are important details.
Enable is like CS, chip select, which means data send to it is only valid for that device if this pin is active.
That way one can use 1 bus for all devices and 1 extra pin per device to let it know this information is valid for that device.
Agreed. I am confused. Thus, my questions. I have listed exactly as the labels are silk screened on the the CNC Shield PCB.
I am hoping that others have figured out what the header labels refer to or point to some better documentation on the CNC Shield.
Very valid point about the link. All the documentation I have found is at:
The documentation there is on the v3.00 Shield. I have the v3.03 and they are slightly different. Still, I am unable to find a description of the header pin outs I listed above.
OK, that link helps.
The left description is valid for the left header, right for right header.
The next ones are
2 nd row: Left is step, right is direction for the X axis.
3rd row: Left is step, right is direction for the Y axis.
4th row: Left is step, right is direction for the Z axis.
5th row: Power supply to the module, 5 volts left and GND right.
Because there is no indication that ENable is active low, i suppose it is active high.
So if 5 volts are put on this pin, the shield enables it.
Reading a bit on that site, i found this remark:
Added a breakout header for all the Axis’s.
That means these headers offer you an extra output to some other driver boards that use these same signals, but do not fit the connectors.
I don't think you need this.
Maybe you can use them to connect some LEDs to it(don't forget the accompanying resistors) and see what your board is doing.
There is an other remark on the site that you need to adjust the driver boards.
The link leads you to some general driver polulu driver page, not to the adjustment procedure.
Read this, scroll down to about 65% of that page and find something out about setting current limiting.
That procedure is about rotating a potentiometer.
It is probably set to the maximum position of one side, limiting the current at a very low level.
Read the instructions and get that motor spinning.
cpwfx:
since you got the shield working, what steps did you have to take?
Basically it boiled down to power draw. I had driven these steppers on several projects with 5VDC before, but by using my own H bridge and not the CNC shield. The CNC shield needs 8VDC to work. Also, with the two steppers running loaded I am pulling 1.3 Amps. Once I starting used a better spec power supply things started moving forward.
I currently have the rig attached to an Etch a Sketch. Works fine writing gcode manually, but I am having difficulties finding a program that will convert simple text or a simple BMP image to gcode. There are programs that do this, but each have their own let of limitations so I am continuing the hunt.
I'll take any suggestions on Windows XP software that will translate text or BMP to gcode..
I suspected I was running in to the same issue with my own test as well. I was trying to run the shield initially with a 9VDC battery that had a bit too much shelf-life on it, so changing to a 12VDC 4A PSU resolved it for me and I got the stepper whirring away using GRBLController on OS X. I zapped GRBL on an Arduino Uno r2 with the Protoneer provided library though the IDE, simple enough.
I was worried that some of the jumpers might have been causing issues but that was not the case. As everything seems fine so far it's easier to continue with configuring micro steps etc. as there were quite a few thing that could've potentially gone wrong, including my soldering.
cpwfx:
I was worried that some of the jumpers might have been causing issues but that was not the case.
I had the same concern, but like you, found it was not an issue. The shield comes with so many jumpers and AUX header pins, but near zero documentation on what they do. TIP: Ignore them all until the rig is running.
Very nice.
Can you give me an idea how this setup performs compared to a full blown Emc2 or Mach3 CNC controller setup? Are the "real-time" issues of timing an issue any more? Seems very promising.
IronJungle:
I hook up a driver and stepper to the X-axis and powered on the shield. No smoke, but no whirling stepper either. Regardless of what G code command I try I get no movement, but the IDE terminal does echo back "ok" after a valid command. I have verified that the ENABLE lines on the A4988 align with the correct place on the CNC Shield.
Hi Guys,
I'm new to all of this and read through your forum looking for answers.
I'm experiencing this exact problem (see above quote). Only difference is that I'm using a 12V 30A PSU (used on 3D Printers) So according to me it can't be a power issue.
