"Garbage receive MPos" on Status Request with "?"

[Jens101]

Hello, I an pretty new to githup. However I stumbled across a issue, which might be worth reporting.

After an update to version 0.9.14.306 bCNC connected at start-up to the controller without clearing the alarm bar to idle. Also bCNC stopped communicating to the controller. Checking the Terminal window I got the following Message:

Garbage receive MPos: <Idle|MPos:0.00,0.00,0.00,0.00|Bf:31,128|WCO:-733.00,-884.00,-5.00,0.00> [G54:-733.00,-884.00,-5.00,0.00] [G55:-890.00,-745.00,-5.00,0.00] [G56:-636.00,-499.00,-88.00,0.00] [G57:0.00,0.00,0.00,0.00] [G58:0.00,0.00,0.00,0.00] [G59:-561.65,-740.92,-91.75,0.00] [G28:0.00,0.00,0.00,0.00] [G30:0.00,0.00,0.00,0.00] [G92:0.00,0.00,0.00,0.00]

It seems that the GRBL1.py goes not cope with 4 axis any more.

A downgrade to bCNC 0.9.14.304 solved the issue for the moment for me.

[Harvie]

Reported to the author of 6 axis support... Hopefully they will figure where the problem lays... https://github.com/vlachoudis/bCNC/pull/1384

[tsmarks]

I am looking into it. What OS are your using? My test laptop running Ubuntu does not have this problem. And what grbl settings ($$) are set on your machine? What grbl install are you using?

It appears the controller is reporting a 4th axis position seen here: MPos:0.00,0.00,0.00,0.00 My 3 axis grbl only reports 3 and my other controller reports 6. If this is a use case, some changes around line 119 to allow the 4th axis with out 5 and 6 might work. Without being able to reproduce the error, I don't want to toss test code out. Would you be willing to try experimental code?

[Jens101]

Thanks a lot. I was not sure if this issue was important enough. My bCNC runs on: PRETTY_NAME="Raspbian GNU/Linux 10 (buster)" NAME="Raspbian GNU/Linux" VERSION_ID="10" VERSION="10 (buster)" VERSION_CODENAME=buster ID=raspbian ID_LIKE=debian Linux cnc1 4.19.118-v7+ #1311 SMP Mon Apr 27 14:21:24 BST 2020 armv7l

The grbl responds to $I with: [VER:1.1f5.02/24/2018:] [OPT:VMH,AVR_644,SPI_SR,SPI_DISP,PANEL,C_AXIS]

To $$ it responds with: $0=10 $1=25 $2=0 $3=0 $4=1 $5=0 $6=0 $10=3 $11=0.010 $12=0.050 $13=0 $20=1 $21=0 $22=1 $23=3 $24=100.000 $25=2000.000 $26=25 $27=5.000 $30=1000 $31=0 $32=0 $100=79.839 $101=79.974 $102=320.000 $103=10.000 $110=7500.000 $111=7500.000 $112=1000.000 $113=10.000 $120=250.000 $121=250.000 $122=50.000 $123=10.000 $130=750.000 $131=900.000 $132=130.000 $133=10.000

I have no problem to test experimental code. I just would set up a separate SD Card in order to avoid any harm to my existing installation. Maybe I could even learn a bit.

[tsmarks]

OK. I think I see the issue. Your grbl is reporting a "C Axis". If you change line 119 in GRBL1.py from "if len(word) > 4:" to "if len(word) > 5:" it SHOULD ignore the C Axis report and treat your system like a 3 axis. IF you installed using pip the file could be in /usr/local/lib/python2.7/dist-packages/bCNC/controllers/. IF you downloaded the zip or "git cloned" it will be in controllers where ever you put the bCNC.

That really is only a temporary fix. I was unaware of a case where grbl reported only 4 axis. All I saw was 3 or 6. We really should fix this to allow bCNC to acknowledge the 4 axis report if there is a firmware that reports it... but one issue at a time. Let's get this working before digging a bigger hole.

Does anyone else have a 4 axis firmware? Do we want to work this special case into bCNC or just let it treat it as a 3 axis?

[pmchealey]

Exactly the same for me. I'm using python 3.8.3 or 2.7.16 (same problem) When connected, I receive continuously: // Garbage receive MPos: <Alarm|MPos:0.000,0.000,0.000,0.000,0.000|FS:0,0|WCO:0.000,0.000,0.000,0.000,0.000> Garbage receive MPos: <Alarm|MPos:0.000,0.000,0.000,0.000,0.000|FS:0,0|Ov:100,100,100> Garbage receive MPos: <Alarm|MPos:0.000,0.000,0.000,0.000,0.000|FS:0,0> Garbage receive MPos: <Alarm|MPos:0.000,0.000,0.000,0.000,0.000|FS:0,0> Garbage receive MPos: <Alarm|MPos:0.000,0.000,0.000,0.000,0.000|FS:0,0> Garbage receive MPos: <Alarm|MPos:0.000,0.000,0.000,0.000,0.000|FS:0,0> Garbage receive MPos: <Alarm|MPos:0.000,0.000,0.000,0.000,0.000|FS:0,0> Garbage receive MPos: <Alarm|MPos:0.000,0.000,0.000,0.000,0.000|FS:0,0> Garbage receive MPos: <Alarm|MPos:0.000,0.000,0.000,0.000,0.000|FS:0,0> Garbage receive MPos: <Alarm|MPos:0.000,0.000,0.000,0.000,0.000|FS:0,0> // When I unlock, no more communications... I try the modification on GRBL.py : no change I return to the .304 version and all is good.

Thank you for your help

[pmchealey]

... One more information There is this message in the terminal when I unlock : // Traceback (most recent call last): File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/threading.py", line 932, in _bootstrap_inner self.run() File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/threading.py", line 870, in run self._target(*self._args, **self._kwargs) File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/bCNC/Sender.py", line 777, in serialIO elif self.mcontrol.parseLine(line, cline, sline): File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/bCNC/controllers/_GenericController.py", line 201, in parseLine self.parseBracketSquare(line) File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/site-packages/bCNC/controllers/GRBL1.py", line 218, in parseBracketSquare CNC.vars["G92C"] = float(word[6]) IndexError: list index out of range //

regards,

[Jens101]

Sorry but I've also bad news. The modification did not show any effect. In GRBL1.py I also changed line 128 to "CNC.vars["state"] = "Garbage 5 receive %s: %s"%(word[0],line)" (adding the "5"). However the message stays the same with out the additional "5". Maybe the change didn't show any effect, because bCNC loads GRBL1.pyc instead of GRBL1.py. I don't know how to check that. Attached is a screenshot for illustration.

[tsmarks]

OK. I see two other lines with the same issue:

lines 169 and 215

if len(word) > 4: can be if len(word) > 5:

If that doesn't work.... could you add print(word) after 109, so i can see what your grbl is sending.

@pmchealey I noticed your error is slightly different than @Jens101 See jens is reporting four positions "<Idle|MPos:0.00,0.00,0.00,0.00|..." While yours is reporting five. If you run a $$ do you have a 114, 124, and 134? It would appear you have a 5axis config? If my guess correct, you may need to use "len(word) > 6" to get this to work.

After we get this working, I have a good idea of what the final code should be to fix this the right way. We should be able to test and commit. Thank you for working through this.

[pmchealey]

Thank you Tsmarks everything is working! I change all for "len(word) > 6" in grbl1.py. There is still a little problem : no display for A in DRO (stay at 0) when I jog

[Jens101]

For me it does the trick as well. Thanks. To be perfectly honest, I did not get why. Anyway. Just for giving a complete feedback here is the console output, resulting from the 'print' inclusion at line 110. bCNC.txt

[tmbdev]

I'm having the same problem. There seem to be a lot of places where the six axis support assumes that anything with more than 3 axes is 6 axes.

I have a 4-axis controller (an ESP32-GRBL board). The same controller comes in 2, 3, 4, and 6 axes, so I think you can't make assumptions like that.

A quick fix is modifications like this (modified from GRBL1.py):

        if word[0] == "G92":
            CNC.vars["G92X"] = float(word[1])
            CNC.vars["G92Y"] = float(word[2])
            CNC.vars["G92Z"] = float(word[3])
            #if Utils.config.get("bCNC","enable6axis") == "true":
            if len(word) > 4:
                CNC.vars["G92A"] = float(word[4])
            if len(word) > 5:
                CNC.vars["G92B"] = float(word[5])
            if len(word) > 6:
                CNC.vars["G92C"] = float(word[6])
            CNC.vars[word[0]] = word[1:]
            self.master._gUpdate = True

I still haven't tracked down all of these problems, but if I can get something that works on my 4-axis controller, I'll send a PR.

Somewhat cleaner is to make this an actual loop, like this:

axis_names = "X Y Z A B C D E F G".split()
...
for name, value in zip(axis_names, word[1:]):
    CNC.vars["G92"+name] = value

Long term, it might be worth thinking about introducing a class to hold a collection of axis values and associated axis names, and methods like "axisobj.stateToVars(CNC.vars, prefix="G92").

(Also, to avoid breaking existing systems with new features like this, it might be worth having some automated test cases that run bCNC against a simulator.)

[tmbdev]

NB: small PR was incorporated with the above conditionals yesterday. That fixes the immediate problems of not being able to run at all on 4-axis machines.