Auto_Bed_Leveling: Enhanced G29 command

[Roxy]

>>>G28
SENDING:G28
>>>M114
SENDING:M114
X:84.00 Y:97.00 Z:-0.78 E:0.00 Count X: 84.00 Y:97.00 Z:-0.78

I just thought i'd do another M114 to see where it thinks it is after the M48 and its totally different!?

**Just thought i'd run it again to make sure its a consistent result
>>>G28
SENDING:G28
>>>M114
SENDING:M114
X:84.00 Y:97.00 Z:-0.78 E:0.00 Count X: 84.00 Y:97.00 Z:-0.78

>>>M114
SENDING:M114
X:84.00 Y:97.00 Z:-0.77 E:0.00 Count X: 84.00 Y:97.00 Z:9.23

I don't understand why you say it is totally different? The M114 after the G28 is consistently reporting the nozzle to be at -.77 or so.

Right now... It looks like the code is behaving as it should. We need to understand things a little better.

Let's repeat the G28 and M114 with these changes:

#define Z_RAISE_BEFORE_HOMING 0 // (in mm) Raise Z before homing (G28) for Probe Clearance.
#define Z_RAISE_BEFORE_PROBING 0 //How much the extruder will be raised before traveling to the first probing point.
#define Z_RAISE_BETWEEN_PROBINGS 0 //How much the extruder will be raised when traveling from between next probing points

You should manually move the nozzle to a safe height after connecting before issuing the commands. This might help us understand where the strange values are coming from.

[brainscan]

The first M114 shows z -0.77 and after M48 z 9.23 which is much closer to what it should be even though it's in the same position when I issue the command.

I have no idea what the custom m code point thing is, I've tried raising it as a question on a few forums and no one has got back to me. I noticed it's in the main marlin code and was added a few months ago with absolutely no explanation as to what it does or how it affects the printer. I didn't want to comment it out incase it switched something vital off. I thought if it's in there with no explanation the developers must have felt it to be important. I will try what you've suggested and get back to you.

[Roxy]

The first M114 shows z -0.77 and after M48 z 9.23 which is much closer to what it should be even though it's in the same position when I issue the command.

I have no idea what the custom m code point thing is, I've tried raising it as a question on a few forums and no one has got back to me. I noticed it's in the main marlin code and was added a few months ago with absolutely no explanation as to what it does or how it affects the printer. I didn't want to comment it out incase it switched something vital off. I thought if it's in there with no explanation the developers must have felt it to be important. I will try what you've suggested and get back to you.

I edited out that comment about the CUSTOM_M_CODE. But I guess you saw the post before I did that. That code is benign if you don't send your printer an M851. I think it was in there to help the developer doing the bed leveling. It is in my code base (and everybody elses) too.

I think we want to concentrate on the G28 and the M114. That is the minimum code to cause the problem and we should be able to figure out what is causing your problem.

[brainscan]

I edited out that comment about the CUSTOM_M_CODE. But I guess you saw the post before I did that. That code is benign if you don't send your printer an M851. I think it was in there to help the developer doing the bed leveling. It is in my code base (and everybody elses) too.

I think we want to concentrate on the G28 and the M114. That is the minimum code to cause the problem and we should be able to figure out what is causing your problem.

I was reading your post in the notification email so only just seen the edit. Thanks for explaining the m code points, I won't worry about it now. Here's what I got after changing everything to 0
>>>G28
SENDING:G28
>>>M114
SENDING:M114
X:84.00 Y:97.00 Z:-0.78 E:0.00 Count X: 84.00 Y:97.00 Z:-0.78

(and previously I had said the safe z homing wasn't so safe but just ignore me I hadn't spotted that it moves all three axis together as it was too quick)

[Roxy]

OK, there is something going on here we don't understand. We have code being generated that we don't know about!

- First, are you using Arduino v.22 ?

- Lets add a couple lines of debug code to the G28 command in Marlin_main.cpp Please make it look like this:

case 28: //G28 Home all Axis one at a time
#ifdef ENABLE_AUTO_BED_LEVELING
plan_bed_level_matrix.set_to_identity(); //Reset the plane ("erase" all leveling data)
#endif //ENABLE_AUTO_BED_LEVELING

SERIAL_PROTOCOLPGM("??? Going to zero Z-Axis with offset of: "); // <---<<< New code to let us see what it thinks is the right thing to do
SERIAL_PROTOCOL_F(Z_PROBE_OFFSET_FROM_EXTRUDER,6); // <---<<< New code to let us see what it thinks is the right thing to do
SERIAL_PROTOCOLPGM("\n"); // <---<<< New code to let us see what it thinks is the right thing to do

saved_feedrate = feedrate;
saved_feedmultiply = feedmultiply;
feedmultiply = 100;
previous_millis_cmd = millis();

Once that is built and flashed, repeat the G28 and M114. We'll get this figured out with a few more iterations....

[brainscan]

I had to start using arduino 1.0.1 as it stopped compiling when I downloaded a fresher copy of marlin a few months ago. Do I need to use 0022? I will do what you've said otherwise.

[Roxy]

I had to start using arduino 1.0.1 as it stopped compiling when I downloaded a fresher copy of marlin a few months ago. Do I need to use 0022? I will do what you've said otherwise.

Yes, I think you should be using V.22 I tried to switch to v1.0.1 and had problems with the Marlin Serial Communication code not wanting to compile. I looked at what it would take to warm that over and 'fix' it. I decided against doing that because any updates to the Marlin code would have to be crossed over again and again. I figured I would wait until the community was ready to all move at once to the updated version of Arduino.

But go ahead and compile this with v1.0.1 just because I'm curious what it is going to say about the value of Z_PROBE_OFFSET_FROM_EXTRUDER

Roxy EDIT:

Ah... It looks like the community has moved on... Maybe you shouldn't go back to v.22 ????
Let me check this out a little more.

OK... It looks like the current code base compiles clean in Arduino v1.0.5 !!! So it should be OK to keep using your v1.0.1 I'm going to migrate my stuff over to the new environment.

Go ahead and add those 3 lines to the G28 command.

[brainscan]

Sorry had to get some food or I was going to start making mistakes (well more than usual).
>>>G28
SENDING:G28
??? Going to zero Z-Axis with offset of: -7.400000
>>>M114
SENDING:M114
X:84.00 Y:97.00 Z:-0.78 E:0.00 Count X: 84.00 Y:97.00 Z:-0.78

[Roxy]

And you still have these lines in the Configuration.h file?

#define Z_RAISE_BEFORE_HOMING 0 // (in mm) Raise Z before homing (G28) for Probe Clearance.
#define Z_RAISE_BEFORE_PROBING 0 //How much the extruder will be raised before traveling to the first probing point.
#define Z_RAISE_BETWEEN_PROBINGS 0 //How much the extruder will be raised when traveling from between next probing points

[brainscan]

And you still have these lines in the Configuration.h file?

#define Z_RAISE_BEFORE_HOMING 0 // (in mm) Raise Z before homing (G28) for Probe Clearance.
#define Z_RAISE_BEFORE_PROBING 0 //How much the extruder will be raised before traveling to the first probing point.
#define Z_RAISE_BETWEEN_PROBINGS 0 //How much the extruder will be raised when traveling from between next probing points

Yes, they are all still set to 0