I have been trying to get the grbl CNC shield working on the Uno. Problem is that the stepper drivers are beiing disabled by a 4.55v across the EN (pin 1 on the driver). I looked at the GRBL schematic and there is a pull up resister attached to the grbl pin that goes to the arduino digital pin 8. When I check the output of that pin without the grbl in place, I get a wavering voltage of < 1v. My question is this...would that indicate that the pin is floating rather than being LOW?? If the digital pin 8 is floating, would not the pull up resister on the grble board bring the EN HIGH??
I have been trying to get this thing to work for three days now and I know a bit more than I did three days ago, but still not enough to figure out what to do about it. Even though I have the GRBL source code available to me, I have only a rudimentary understanding of C++ and not sure where to look to answer my question.
Hmmmmmm....Interesting response. I came to this forum because it was suggested by a response from a member on a CNC forum. Also, if you do a search for GRBL on this forum, you will find many, many questions related to GRBL (just not exactly my question). My question has more to do with electronics and how microcontrollers work than GRBL specifically. Also, I have gotten a lot of electronics help on this forum even though my questions did not always pertain to programming.
If I have misinterpreted your response, I apologize.
I was not saying "go away". I was simply saying that there may be more expertise elsewhere. You had not told us that you had already been searching on CNC Forums.
My understanding of GRBL is that it is well tested and "just works" if the proper configuration is implemented.
Thanks for clerifying. Turns out that the problem was a bad UNO. Got another and it worked fine. I guess there was a bad io pin on eight. I was able to communicate with the GRBL fine with $ codes and the Uno tested out fine in another project. That’s what made it so hard for me to comprehend, but none the less, changing the uno fixed the issue.
The one that worked was a clone. The one that didn’t was the real thing. That’s another reason I had a hard time diagnosing...blind allegiance to the gods of Arduino. Most of the time though, they deserve it.