ALARM: Homing fail

ALARM: Homing fail

Hello and thank you for support! This first time build is an Eggbot/ Smoothie Board/ Laser Diode. I am trying to home one axis at a time. Starting with Y axis. It keeps crashing. Console says ALARM: Homing fail. I do not yet have endstops set up for X axis. Y homes to MAX (instead of MIN) Need some help debugging please.

My config file in Paste bin:
file:///.file/id=6571367.12888372180

Here is some console history:

M107

M107

ok

ok

$X

G28.2 XY

ALARM: Homing fail

ok

G21

?

error:Alarm lock

<Alarm|MPos:-200.0000,-400.0000,0.0000|WPos:-200.0000,-400.0000,0.0000|F:4000.0,100.0>

ok

Starting stream

G21 G54

G91

G1 X0 Y2 F400 S0

G90

M2

error:Alarm lock

On or near line 0:

error:Alarm lock

On or near line 0:

Stream completed in 0:00

error:Alarm lock

error:Alarm lock

ok

ALARM: Abort during cycle

$X

[Caution: Unlocked]

ok

ALARM: Abort during cycle

$X

[Caution: Unlocked]

ok

Hi,

First of all, you should provide a public link to pastebin… This is not one.
I understand you don’t have any homnig switches. There are many solutions (one at a time!):

  • Try to add homing switches
  • Revert polarity of pins configurer for homing switches (always on). Smoothie will thing they are activated (alpha_min_endstop, beta_min_endstop, gamma_min_endstop). To reverse, pu a ^ at the end of pin definition if not present or remove it if presenf (ex : beta_min_endstop 1.28^ or beta_min_endstop 1.28)
  • Try to disable Cartesian homing in your conf (cartesian_homing false)

Hope this will help.
JPC

Hi JPC
Oops, Here is the config in paste bin: https://pastebin.com/2JRgGQHT

I have dug a little deeper and found a few posts where homing has some challenges(errors) with this Smoothie Board (2015)
-I have end stops on the Y axis (the pen arm), but not yet on the X axis.
-My understanding is that ^ is pull up, v is pull down, reverse/invert is !
-I don’t see in the config file a line that says Cartesian homing, (unless I should add it)

thanks for your input!

Thanks for the config file.

First thing to know about your homing solution is:

  • Is it a simple passive switch?
  • Is it an active switch (a little board, delivering a voltage, frequently with a led on it and needing to be connected with 3 wires)
  • Is it another solution (optical, magnetic, etc…)?

It this is a passive switch, the simplest way to connect it, is to wire the switche between groud and input, and setting the input as reversed (!) and pullup (^). When switch is not active, the pullup give a 3.3V to the uP input. The invert sign(!) tells smoothie to understand that as a logic zero.

Homing direction (alpha_homing_direction & alpha_homing_direction = home_to_min) suggest your switches are supposed to be at the machine zero. Motor will decrease coordinates to reach homes.

So alpha_min_endstop & beta_min_endstop will be used as pin definition for min X and min Y home switches. Alpha config, suggest a passive switch connected to pin 1.24, inverting boolean logic and setting up the pullup (^!). That should be good for a passive switch between gnd and input (normally opened). You shoud put one on this axis, since it a nonsense to home only one axis…

Beta switch config (1.26^ ) have got a pullup, but is not inverted, If no switch connected to it, it will be seen as a “switch activated” input (logic 1 all the time to the input because of pullup). I don’t understand how you’ve cabled a switch on this input, but at least i suggest to connect a NO passive swich between GND and INPUT, and add the ! to the definition.

If you’re connectig active switches (delivering a voltage), remove the pullup (^), and insert and invert sign (!) only if your switch is delivering 3.3 or 5V when not activated.

Your homing order (homing_order YX) suggest you’ll home Y then X. If there’s no switch on X, why to home it? Not sure if removing X in homing order will be enough to home with a single axis. You’ll have to try.

Hope this will help.

-Thank you for your input Jean-Phillipe!

-I am using passive switches with just two wires. They are wired to be NC (normally closed, when pressed they are NOT connected to common). I was advised that this cuts down on "noise”

-Y axis switches (Min and Max) are installed but not X axis switches (yet). As you say, it is nonsense to only home one axis, so I set homing as “false”

-is it possible to have Y switches only set as soft or hard end steps and not use auto homing at all? Then I can manually position Laser using jogging and try to keep it within working area using only software.

-Is is correct to use both min and max end steps enabled?

New Config file: https://pastebin.com/8QfaSTEC

For Y axis, since you’ve connected as NC, it should be connected between GND and input. The pullup you’ve activated is pulling to 1 when switch is activated. So you should not add a ! to pin definition, since it’s positive logic !

I don’t think you can have min and max active at the same time in the configuration. You can comment beta_max_endstop because you’re homing in the direction home_to_min.

Not sure what you should do with homing_order … Maybe only Y? Does X axis moves when you start homing? Did you test your cabling with a voltmeter on the card whil activating switch?

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