grblShield and stepper wiring

[Tom Smith]

HI all - I am putting together the connectors for my electronics package as I wait for the mechanical kit. I have purchased a grblShield, and am trying to wrap my head around the connections. I've isolated the pairs, not difficult, of wires from the steppers - in my case, using the NEMA 17 motors from SparkFun, it is Red-Black and Green-BLue.

The dots I have not been able to connect is, when looking at the grblShield, is what order these should be connected. 4 pins per axis, but does it matter if I hook up R-K-G-B, or G-B-R-K, or B-G-K-R, or K-R-B-G??

I assume that each pair has a polarity, but again, not sure how to determine this. I figured that will I sift through the forum, and the grblShield pages, etc, I'd throw the question out here so that once I or someone else answers the question, it will be easier for the next person to find the answer.

Thanks!

Tom

[alpha]

I guess you use this stepper: http://www.sparkfun.com/products/10846
if so this data sheet from the sparkfun web page will answer your questions: http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Robotics/42BYGHM809.PDF

As far as I understand it is black pin 1 green pin 2 red pin 3 and blue pin 4... at least that is what I did. I do have the synthetos.com grbl shield. However it is possible to reverse the direction in the grbl settings - so I don't think it is that important.

[Tom Smith]

Thanks a lot, Markus - very helpful, and a good reminder to me to look for datasheets.

[alpha]

After the wiring is done I sure you want to study those two threads that talk about the grbl configuration and some Z axis issues:

http://www.shapeoko.com/forum/viewtopic.php?f=4&t=221
http://www.shapeoko.com/forum/viewtopic.php?f=3&t=237

[Tom Smith]

Thanks all - one final (?) question - which pin on the grblShield motor connectors represents pin one? Assuming the board is oriented so that the connectors are on the side farthest from you, and are labeled, from left to right, X Y Z, is pin one on the left or the right for each axis connector?

(I did look through the grblShield wiki this time, hoping to not ask something that is answered elsewhere, but didn't find what I was looking for)

Thanks!

Tom

[edwardrford]

Hi Tom,

Oriented in the direction you're talking about (like in this picture: http://www.synthetos.com/wiki/index.php ... grblShield) pin one would be on the right.

[alpha]

Hi Tom,

Oriented in the direction you're talking about (like in this picture: http://www.synthetos.com/wiki/index.php ... grblShield) pin one would be on the right.

There is one thing that is really confusing and that it a little 1 that is printed on the left... or do I imagine things?

[edwardrford]

The other thing is that to be honest, it doesn't matter which one is pin 1. As long as your pairs are together, your stepper will work. If it turns in the wrong direction, change the invert bits in grbl

[Tom Smith]

Hi Tom,

Oriented in the direction you're talking about (like in this picture: http://www.synthetos.com/wiki/index.php ... grblShield) pin one would be on the right.

There is one thing that is really confusing and that it a little 1 that is printed on the left... or do I imagine things?

Alpha - I interpreted that as part of the v1, or Version 1, of the grblShield (there are two versions, so far as I can tell). Mine is a V2 board.

Oriented in the direction you're talking about (like in this picture: http://www.synthetos.com/wiki/index.php ... grblShield) pin one would be on the right.

Thanks Edward

[aldenhart]

Pin 1 is AOUT and it is on the side of the motor plug located closest to the power terminal block (for each of X, Y and Z). This is the same for both v1 and v2 boards.

As Edward says, the exact pinout actually doesn't matter. As long as one winding goes to the A terminals (pins 1 and 2), and the other to the B terminals (3 and 4) then the motor is happy. The only variance is if either pair is reversed the motor will run in the opposite direction. If the motor runs backwards from the way you would like it you can either reverse one of A or B wire pairs (hardware polarity), or set / clear the right bit in the grbl dir invert mask (software polarity).

Ref: http://www.synthetos.com/wiki/index.php ... or_Pinouts
Ref: https://github.com/grbl/grbl/wiki/Configuring-Grbl

-- Alden