[x2df]

Ray,

As Rick has said, you can use both hall and mechanical switches. It would be best to use the hall for homing because of their accuracy. Then use the mechanical as the limit if you so desire, as a limit doesn't require much accurracy at all.

The hall effect switch can be wired as normally closed or normally open depending on the electronic design. They can also accept any voltage you desire to use them with, if designed with an optocoupler or optoMOS.

I have designed my switches with an optoMOS and you can run up to 60v through them to switch, but they would require a 5v source to power the LEDs and the sensor. I have also designed my switches to be selectable for normally open or normally closed operation.

So running a control board (i.e. G540) that puts out 12v through a mechanical switch, will also work with a hall switch if designed in similar fashion as mine have been.

[x2df]

I should add that I believe the hall switch works up to 25v for the Honeywell and 28v for the Allegro.

[bcer960]

x2DF,

I have been looking over your website, and will contact you through there.
These are the switches I have installed, but are not hooked up.
https://nicegear.co.nz/sensors/hall-...sensor-module/
When I was using a xylotex board, I had them working, but I am not sure how to connect them to the G540.

Ray

[RicknBeachcrest]

Rick,
How are your hall effect switches wired? I upgraded to the 540 a couple of years ago, but the halls I have are only 5v, and the 540 puts out 12v (that might be wrong I haven't looked at it in awhile, I just remember it was higher than the halls would work on)

Thanks
Ray

Take a look at post no 2 in this thread.
"The easiest way to understand these sensors is to see the output like a switch to ground, whenever the magnet is present."

The 5 volts is only used to run the sensor. When the hall effect switch is tripped, it connects ground to the Out. The Out on the sensor is connected to one of the four inputs to the G540, So when the hall effect switch is tripped, the input on the G540 (that you have selected for your home) is grounded (and brought to a low state). And that is how Mach3 knows that home switch has been tripped.

Here is the post in my build log that talks a bit more on the home switch.
http://www.cnczone.com/forums/cnc-wo...ml#post1285974

Rick

[x2df]

Ray,

Those switches you have linked work, however, there are problems with them, and they have been discussed somewhere in this thread, as well as the hooking up to the G540.

From Memory, I'll try to elaborate on the problem with the switch you linked....

The big problem with those switches is that if you use the holes supplied with it to mount the switches, you will end up crushing the capacitor and resistor that is shown. Those are just way to close to the holes that are drilled on that board. Bad design. Other then that and the large circuit board that comes with it, they are pretty much as the same configurations as what Romanlini has on the first few pages of this thread. Pretty basic. A single LED for showing it has been triggered. Those Freetronic switches are Bi-Polar, meaning they sense both south and north pole of the magnet. I have not used them, but I would think that could cause problems. My switches, as well as most of the other ones designed here, as well as the ones Romanlini designed in the first few posts of this thread, are Uni-Polar, meaning they only detect one side of the magnet.

Now, the problem, if I remember correctly, with the G540 and these hall switches, is that a Diode may be needed to hook these up to it. Also, one thing that was discovered is that the ground for the switches, as well as the ground wire for the G540 itself need to be tied together for the switches to operate correctly. The G540 puts out some sort of ground loop and the switches act funny if the ground wire of them are NOT tied together with the ground of the G540. If I diode is needed, a small 1/2W 1N4001 should be sufficient enough.

This has been discussed in this thread, though I can't remember which posts.

I recently got a new computer system, and I will need time to hunt down the proper wiring schematic for wiring these up to the G540. If I find it, I'll post it.

I also want to add, The G540 also has a 2K2 pull-up resistor on it's outputs for limit/home switches. This will cause a problem if using less than 5volts if memory serves me correctly. The G540 might drop too much voltage across that resistor, and may not see the potential ground from the Limit switch it needs to see to activate.

[bcer960]

Thank-you both rick and x2df for your replies.
-Rick, I did not understand about what the 5v does for the hall effect, although I did read the original post I still didn't understand that the voltage could be external from the G540.

x2df- I found out about the mounting holes when I first installed them. I did not crush the component's, but did have the board short out through the mounting screws. A fiber washer between the screw head and the board fixed this.I have styrene spacers behind the board, and this may have saved me from the crushing.
- I did not have an issue with it being bi-polar. With the xylotex, it worked fine.
-If you find the schematic, that would be great.

Ray

[RicknBeachcrest]

Thank-you both rick and x2df for your replies.
-Rick, I did not understand about what the 5v does for the hall effect, although I did read the original post I still didn't understand that the voltage could be external from the G540.


Ray

The 5 volts is what powers the sensor and this voltage needs to come from somewhere (and not from the g540). You can think of the sensor as a little switch that needs power to work. Some people will use the 5 volts from the usb on the computer. I chose to use a separate 5 volt power supply, since I had other things that needed 5 volts. And these power supplies are not that expensive.

Just make sure all your DC negatives (what some may call ground) are connected to each other.
Hope this helps some.
Rick

[FelixPQ]

Edit: I found a good solution for using these with the G540 post #664.

I have read many post on this thread and I still didn't find a definite answer on using these hall effect sensor in parallel on 2 g540 inputs. I see so many versions of Roman initial design, some without additional components and some with more component. I gave up after reading about 30 page of the initial posts.

The 2 inputs are needed because I have a dual x axis ballscrew machine using Mach3 auto squaring macro. I also assume it would be extremely difficult to setup or position the sensors mechanically so that my Y axis is "perfectly" square with my X axis every time hit the home all button. I would appreciate any suggestion on how to proceed?

Thanks,
Yves

[deeph46]

Hi,

Yesterday I used this sensor as a limit switch. I can get M1, M2 and M3 Limits lit (yellow color) in Diagnostics.
But have problem when run Ref All Home. Clicked Ref All Home, the Z axis start looking for a sensor. Then I put/hold the magnet above the sensor and the Z's DRO still running/counting. Until I remove the magnet, the Z axis then zero'ed. X and Y axis do the same.
I test that procedure without connecting the motors, just control box and a Mach3.

Do I missed something?

Thanks
deeph

[x2df]

Hi,

Yesterday I used this sensor as a limit switch. I can get M1, M2 and M3 Limits lit (yellow color) in Diagnostics.
But have problem when run Ref All Home. Clicked Ref All Home, the Z axis start looking for a sensor. Then I put/hold the magnet above the sensor and the Z's DRO still running/counting. Until I remove the magnet, the Z axis then zero'ed. X and Y axis do the same.
I test that procedure without connecting the motors, just control box and a Mach3.

Do I missed something?

Thanks
deeph

You may need to check the setting in Mach3. Sounds like you have it set for Normally Open mode, using a Normally Closed Limit Switch.

If the switch is Normally Open, holding the magnet close to the switch will close the circuit and removing the magnet will OPEN (not connected) the circuit, causing a limit to trip.
If the switch is Normally Closed, then holding the magnet close would OPEN (not connected) the circuit and cause the limit to trip.

[deeph46]

You may need to check the setting in Mach3. Sounds like you have it set for Normally Open mode, using a Normally Closed Limit Switch.

If the switch is Normally Open, holding the magnet close to the switch will close the circuit and removing the magnet will OPEN (not connected) the circuit, causing a limit to trip.
If the switch is Normally Closed, then holding the magnet close would OPEN (not connected) the circuit and cause the limit to trip.

What setting should I change? I checked the Active Low.

Red LED lit on my board at pin # 10, 11 and 12 when no magnet near sensor.

EDIT:
Did try again with motors plugged to control box and taped the sensor in X axis, magnet on X carriage.
Clicked Ref All Home, it actually works. X carriage search the sensor, after find the sensor immediately stop for 1 second. Then back about 1mm.

So it works normal now.

I'm using this Hall sensor module (pictured). There are 2 outputs Ao (analog) and Do (digital). I have tried both, looks like Ao is NC and Do is NO.

[deeph46]

Anyone know how to wiring 2 sensors in 1 axis? I'm going to use for ie. X Home and X++.

[x2df]

Anyone know how to wiring 2 sensors in 1 axis? I'm going to use for ie. X Home and X++.

If you have, for example, two ballscrews/leadscrews for x-axis, and want to home each to square the machine, then I think you need a separate switch for each so MACH3 can determine which switch has triggered during the homing process. Some people are using the A-Axis and telling mach3 that it is the second X-homing switch.

For just two switches, as you said for X-Home then X-Limit....You just need one switch. When Mach homes the machine, after which it will see that same switch as a limit. Then just place another switch for the X- (other side of the machine) in series with x-, y-, and z- (if there is one).

[deeph46]

If you have, for example, two ballscrews/leadscrews for x-axis, and want to home each to square the machine, then I think you need a separate switch for each so MACH3 can determine which switch has triggered during the homing process. Some people are using the A-Axis and telling mach3 that it is the second X-homing switch.

For just two switches, as you said for X-Home then X-Limit....You just need one switch. When Mach homes the machine, after which it will see that same switch as a limit. Then just place another switch for the X- (other side of the machine) in series with x-, y-, and z- (if there is one).

Do you mean in my case, I can just use Soft limit for the other end of X axis?

And does like this wiring for 2 switches each axis?
http://www.mycncuk.com/attachment.ph...4&d=1285524715

[x2df]

yes, that diagram is right.

However, if you have two x-axis, then you will need a fourth home switch, and use the A-axis input of the breakout board and let Mach3 know that you need to home both sides of the x-axis to square the table.

I would NEVER use a soft limit or software limit for a machine. Same goes for the e-stop.

[deeph46]

Sorry, but this sensor using signal can I series the signal sensors? Or maybe using paralel?

[x2df]

I don't think you could run it in series without incorporating optocouplers/optomos' into them. But you should be able to run them as in the picture below, however, with that Comparator on that board, I'm not sure if that would cause problems.

Something like this picture :



Also, if you wanted to put an LED on the front of your panel for each of your switches, you can do this.:

[deeph46]

Just tried it, conected to pin 13 it works. When X++ reached the Reset activated. Is it correct? If so how do I reset the sensor, I'm not able to deactivate Reset. Sensor keep on active state. I should wiggle a bit the sensor to make the sensor inactive.

[x2df]

did you use the diodes?

[deeph46]

yes using 1N4002, but didn't work.