I just finished building an ACRO1010 laser engraver using an Arduino Mega 2560 controller running Grbl 1.1g. The engraver works great, except I have never been able to use the Homing Cycle. When homing is turned on, the machine boots in alarm state, as it should. I enter $X to reset and then $H to home. The machine just sits there - no movement with either axis. After about a minute or so it goes back into alarm state. Since the machine is trying to home, I can't use '?' to see what is happening. If I disable the homing cycle the machine works fine, I just manually home it. I'm using limit switches supplied with the kit in a "normally open" mode. I have confirmed they are working correctly with a continuity tester on the Arduino pins. I'm using Pin10 for X-Axis and 11 for Y-Axis. I also disabled Z-Axis homing in config.h, by commenting out the homing definitions and replacing them with: #define HOMING_CYCLE_0 (1<<X_AXIS) #define HOMING_CYCLE_1 (1<<Y_AXIS) #define N_HOMING_LOCATE_CYCLE 1 I'm new to laser engraving and Grbl, so I'm not sure how I can see what is happening to determine where I messed up. A log of a recent attempt is below along with my configuration settings. Any suggestions or ideas are greatly appreciated! Thanks, Jim In the following the machine does not move after the $H commands. Waiting for connection... Waiting for connection... Grbl 1.1g ['$' for help] [MSG:'$H'|'$X' to unlock] error:9 [MSG:Caution: Unlocked] ok ? <Idle|MPos:0.000,0.000,0.000|Bf:35,254|FS:0,0|Pn:XYZR|WCO:0.000,0.000,0.000> ok $i [VER:1.1g.20180813.Mega:ACRO1010] [OPT:VNM+,35,255] ok ? <Idle|MPos:0.000,0.000,0.000|Bf:35,254|FS:0,0|Pn:XYZR|Ov:100,100,100> ok $H ? ALARM:8 ok Grbl 1.1g ['$' for help] [MSG:'$H'|'$X' to unlock] [MSG:Caution: Unlocked] ok ? <Idle|MPos:0.000,0.000,-10.000|Bf:35,254|FS:0,0|Pn:XYZR|WCO:0.000,0.000,0.000> ok $$ $0=5 $1=255 $2=0 $3=0 $4=1 $5=1 $6=0 $10=3 $11=0.005 $12=0.002 $13=0 $20=0 $21=0 $22=1 $23=1 $24=250.000 $25=50.000 $26=25 $27=10.000 $30=1000 $31=0 $32=1 $100=230.620 $101=230.620 $102=500.000 $110=3000.000 $111=3000.000 $112=500.000 $120=15.000 $121=15.000 $122=10.000 $130=914.000 $131=914.000 $132=500.000 ok $X ok $H ALARM:8 ok Grbl 1.1g ['$' for help] [MSG:'$H'|'$X' to unlock] [MSG:Caution: Unlocked] ok ? <Idle|MPos:0.000,0.000,-10.000|Bf:35,254|FS:0,0|Pn:XYZR|WCO:0.000,0.000,0.000> ok
Use our Flashing tool under wizards and tools to setup the 2 axes firmware We did all the compile options for you in there Also use our profile in Grbl settings then
Hi Peter I looked at that option. I'm using an Arduino Mega 3560, the wizard only allows me to select an Arduino Uno or Nano. Do you know which one I should select? Thanks, Jim
Oh in that case neither. Also, most Grbl 2560 builds arent as stable (at the Atmega328 is the more used version) , check the source where you got it from for issues related to homing then, you'll have to discuss this with the Firmware vendor/developer then
Thanks for the insight about the 2560. I was not aware of the stability issues. I may look into an Atmega328 as an alternative.
I found an UNO from an old project. Reflashed it with an empty program to clear it out, then used the Flash Wizard to flash it with the 2 axis option. I'm making progress, but it's still not Homing right. Now when I home, the x-axis will move to the left (-x direction) for 5 mm, pause, then move left for 5mm. Next the y-axis will move closer (-y direction) for 5 mm, pause, move 5mm closer, then stop. It appears the home cycle completes at this point. I have the gantry in the middle and it does not contact any limit switches. If I change the pull off distance from $27=5 to $27=20. It moves in 20mm increments as described above. I have the x-limit switch in pin 9 and the y-limit in pin 10 of the UNO. My current config is below. Any ideas on what is causing this and how to fix it are greatly appreciated. [21:06:48] [ $$ ] ok [21:06:48] [ $I ] [VER:1.1g.20181112:ACRO1010] [21:06:48] [ $I ] [OPT:V,15,128] [21:06:48] [ $I ] ok [21:06:59] [ $$ ] $0=5 ;Step pulse time, microseconds [21:06:59] [ $$ ] $1=255 ;Step idle delay, milliseconds [21:06:59] [ $$ ] $2=0 ;Step pulse invert, mask [21:06:59] [ $$ ] $3=0 ;Step direction invert, mask [21:06:59] [ $$ ] $4=1 ;Invert step enable pin, boolean [21:06:59] [ $$ ] $5=0 ;Invert limit pins, boolean [21:06:59] [ $$ ] $6=0 ;Invert probe pin, boolean [21:06:59] [ $$ ] $10=2 ;Status report options, mask [21:06:59] [ $$ ] $11=0.010 ;Junction deviation, millimeters [21:06:59] [ $$ ] $12=0.002 ;Arc tolerance, millimeters [21:06:59] [ $$ ] $13=0 ;Report in inches, boolean [21:06:59] [ $$ ] $20=0 ;Soft limits enable, boolean [21:06:59] [ $$ ] $21=0 ;Hard limits enable, boolean [21:06:59] [ $$ ] $22=1 ;Homing cycle enable, boolean [21:06:59] [ $$ ] $23=0 ;Homing direction invert, mask [21:06:59] [ $$ ] $24=500.000 ;Homing locate feed rate, mm/min [21:06:59] [ $$ ] $25=200.000 ;Homing search seek rate, mm/min [21:06:59] [ $$ ] $26=250 ;Homing switch debounce delay, milliseconds [21:06:59] [ $$ ] $27=5.000 ;Homing switch pull-off distance, millimeters [21:06:59] [ $$ ] $30=1000 ;Maximum spindle speed, RPM [21:06:59] [ $$ ] $31=0 ;Minimum spindle speed, RPM [21:06:59] [ $$ ] $32=1 ;Laser-mode enable, boolean [21:06:59] [ $$ ] $100=230.620 ;X-axis steps per millimeter [21:06:59] [ $$ ] $101=230.620 ;Y-axis steps per millimeter [21:06:59] [ $$ ] $102=250.000 ;Z-axis steps per millimeter [21:06:59] [ $$ ] $110=3000.000 ;X-axis maximum rate, mm/min [21:06:59] [ $$ ] $111=3000.000 ;Y-axis maximum rate, mm/min [21:06:59] [ $$ ] $112=500.000 ;Z-axis maximum rate, mm/min [21:06:59] [ $$ ] $120=10.000 ;X-axis acceleration, mm/sec^2 [21:06:59] [ $$ ] $121=10.000 ;Y-axis acceleration, mm/sec^2 [21:06:59] [ $$ ] $122=10.000 ;Z-axis acceleration, mm/sec^2 [21:06:59] [ $$ ] $130=914.000 ;X-axis maximum travel, millimeters [21:06:59] [ $$ ] $131=914.000 ;Y-axis maximum travel, millimeters [21:06:59] [ $$ ] $132=200.000 ;Z-axis maximum travel, millimeters [21:06:59] [ $$ ] ok
Check the troubleshooting tab to see if they are "off" before the move (should show green, if they are red invert $5)
Yeah, make sure the NC/NO issue is correct first. But it's usually a noise issue. Connect a 0.1uF/100nF ceramic cap between each of your switch pins and ground, and make sure your limit cables are either shielded wire or inside the grounded machine frame extrusion. That said, I have had grbl just arbitrarily seek its previous "home" and pretend there are totally limit switches at an arbitrary 0,0. Not sure what that behaviour is, I can only assume it's some kind of failsafe buried in the grbl code that I haven't seen yet. It did go away once I had the caps on there though, I think the stepper cables are noisy.
Hi Rob - Thanks for the advice on the noise issue. That solved the problem! After I verified in the troubleshooting tab the swithes were set correctly, I added the 0.0uF cap filters. That cleared up the issue immediately. I had the limit switch wire running inside the vrail for both x and y axis. I was surprised it was noise. I thought that the noise would trigger 'false positives' with the switches. I did not see anything like that in the troubleshooting tab. Regardless, it's now working and I appreicate your and Peter's help in resolivng my problem. I was going crazy trying to figure it out. Jim
