Since you have a new Arduino, let’s start over.
Use the attached .zip file and the grbl upload example to put a fresh copy of grbl version 0.9j on the new Arduino.
grbl-master.zip (367.0 KB)
Hi Larry,
I have the 0.9j version installed. The ? command show me:
Idle,MPos:0.000,19.050,-1.000,WPos:0.000,19.050,-1.000,Buf:0,RX:1,Lim:111
But sometimes show me:
Idle,MPos:0.000,19.050,-1.000,WPos:0.000,19.050,-1.000,Buf:0,RX:1,Lim:100
With the power supply on or off, and with the limit switches wires plugged to the gShield or not plugged, indistinctly. 
Now, show me always Lim:111 and the voltages are:
X: 0.880 V
Y: 0.780 V
Z: 0.062 V
With the power supply off, only the USB.
Do the test again, but this time do it with the gShield unplugged from the Arduino.
Idle,MPos:0.000,0.000,0.000,WPos:0.000,0.000,0.000,Buf:0,RX:1,Lim:000
I bought a second pair of Arduino Uno and gShield and the problem is the same. I don’t understand anything…
I have the same problem even with the motors off. Can I have noise issues with the Arduino and gShield connected only to the USB?
Phil,
Have you tried .1 ceramic capacitors between the Arduino limit input pins and ground? Just may be all that you need. I suspect that the problem is related to the close proximity of the noisy (electrically) output circuitry of the gshield to the Arduino.
John
www.picengrave.com
@Mino
@PhilJohnson
@Zach_Kaplan
I don’t think this is noise.
Mino has done the test with nothing but the Arduino and the gShield. No 24 volt power, no motors, no noise and it fails with the gShield plugged in and does not fail with the gShield not plugged in.
It’s a bit difficult to find this type of problem remotely. Is there some way to work this out so that Inventables can retrieve these two gShields for testing, or if they don’t have the time I would be willing to try and locate the issue if I could get the boards temporarily.
@LarryM
Exactly. With out power supply. Only the Arduino and the gShienld to the USB.
Now, I have two pairs of Arduino and gShield. In the first pair the ? command always show me PIN:110 and in the second pair PIN:111 (Sometimes, in both pairs, the values change to 100 or 011)
Send the gShields to United States is expensive for me, I live in Spain.
I wouldn’t expect you to pay for that.
Did your parts come from the US or are you working with a local company?
So, now we have three boards with the same problem.
That’s the problem. I bought my X-Carve through a shop in London (RoboSavvy) and your technical service is not very attentive to me. I had to wait more than a month until finally they sent the second gShield. I try to talk to them again… Thanks for the help, Larry!
I’m not associated with Inventables, except as a very satisfied customer.
Are you saying that the US customer service is not helpful, or the RoboSavvy customer service is not helpful, or both?
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Oh! I thought you’re part of the Inventables team. No, only the RoboSavvy customer service. I have not yet contacted with the US customer service (Inventables), but I will do. I don’t understand where the problem can be. Two pairs of Aduino and gShield only connected to the USB with the same problem, it is exasperating…
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Yes. That’s why I would really like to know what this problem is.
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I don’t have an X-controller, so my comment is based on things I’ve read on the forum.
I believe that the X-controller is a single PCB Arduino look alike and motor drivers on one board. It does have some noise filtering on the switch inputs.
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I forgot to ask you if you used shielded wire for your homing switches. Do you have shielded wire for the homing switches or did you use the black/white wires from the kit?
You can contact Inventables Customer Success through our support center. In your message please indicate you ordered from Robosavvy but you are having issues. We don’t have access to Robosavvy’s customer information so they won’t be able to find your order number in our system.
Hi, Nuno from Robosavvy here,
We are in touch with @Mino since day 1 and already sent out two gshields, unfortunately UK/ES mail system took more than two weeks to deliver the first gshield so we sent a second one as we would assume the first would be lost.
After reviewing all the case there’s one thing that no one mentioned until now, the solderings on the gshield. The right angle pins needs to be soldered by the customer and from the picture seems that those solderings are bad with solder balls on the pins that do not make a proper connection with the board.
Help on how to to do a good solder
@Mino can you please check the conductivity between the end of the pins (marked with a red circle on the image below) you soldered and the ones that come already assembled?
From your photo only the pin 1 and 2 seem to be properly soldered, all the others look like ball soldering with the pin 5 and 7 being the worst ones.
Hi @PhilJohnson, your soldering job looks as good as you can do with a handheld soldering iron, if you compare both images you can see that yours are all “volcano like” compared with the ones from @mino that are ball shaped
Have you already tested with a new gshield?
by the way, thanks to sparkfun.com for the image 
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