Electronic home switches made easy!

[pinchio]

What is required to add another LED to indicate normal state (green led). The LED would switch off and the red led would come in when the switch is triggered by the field.

Any assistance with actual part number from digikey and wire up schematic would be appreciated for this electronic newbie.

Thank You

[x2df]

What is required to add another LED to indicate normal state (green led). The LED would switch off and the red led would come in when the switch is triggered by the field.

Any assistance with actual part number from digikey and wire up schematic would be appreciated for this electronic newbie.

Thank You

If you are using an LED with less than 20mA supply current, you can use any (preferable a XOR GATE in this situation) Logic Gate. Simply wire the cathode to the output of the LED and wire the Anode of the green LED to the Output of the same logic gate. When the switch is on, it will show as green, supplying the Green LED with current, when the Switch is tripped, it would allow the Logic gate to 'sink' the current of the Red LED.

The input to the Red LED would be just powered from 5 volts or whatever voltage you have, with respect to the proper resistor in line to supply the proper forward voltage of the LED.

The Hall Effect Sensor output would got to one of the A or B inputs of the Logic Gate, (instead of the Anode of the LED as before), and the other input of the logic gate would be connected to ground. Most CMOS Logic Gates will Sink or Source up to 25mA, any more than that, you'll destroy the logic gate. But Your LED's will most Likely reach enough (if not full) brightness at around 10mA anyway.

[jlandry]

Thanks for the reply but I have the MX3660 version. I drew up a diagram on how i think it should be wired up.

Attachment 326294

Naspc, have you tried wiring this up yet? I also have the MX3660 and am looking to connect hall effect sensors.

[nlancaster]

Just buy x2df's kit. Works awesome and looks great!

[blitz355]

Is there a way to keep a controller from moving back outside of the hystersis? When homing my y& slaved a axis, one axis moves for a moment longer than the other (moving away after contact). It's very difficult to get the slaved axis to actuate at the exact same spot as the other.

[RonaldoNZ]

That's by design in order to square the axis.

Sent from my SM-N9005 using Tapatalk

[blitz355]

That's by design in order to square the axis.

Sent from my SM-N9005 using Tapatalk

What? Making it difficult to actuate at the same time? Lol

[RonaldoNZ]

What? Making it difficult to actuate at the same time? Lol

Treat one sensor as fixed and the other you need to tune/position. I wouldn't call it difficult

Sent from my SM-N9005 using Tapatalk

[justCNCit]

Hello, I've been trying to hook up this circuit with the hall effect sensors directly to the parallel port without success.

I have an external 5v power supply. Is the key to use a common ground? Mach 3 registers logic change when parallel port input is closed to parallel ground. The Hall effect puts out 5v relative to its own ground using multimeter, when a magnet is next to the switch. Is a transistor required in order to connect these two circuits?

Thanks
Shawn

[x2df]

Hello Shawn,

I know that some breakout boards, like the G540 if I remember correctly, is kinda touchy and doesn't operate correctly unless the ground pins of separate supplies are tied together creating a common ground point.

Also, you may need to have a diode inline with the circuit to the parallel input. try that.

If you are on a laptop using a parallel port ONLY with mach 3 you may experience other problems than just this as well. If I remember correctly, Laptops using parallel port work okay with Windows 95/98 (or XP too?), but any newer version of windows on a laptop with a parallel port and Mach 3 has problems. In those cases, you would need to get a smoothstepper and use the ethernet or USB ports. Or use a Desktop machine all together. In either case, a Smoothstepper will improve overall performance for you machine no matter what operating system you have on your PC.

[x2df]

depending on your switch configurations as well, you need to program Mach 3 for normally Open (NO) or Normally Closed (NC) limit switch operation. These hall switches are designed to work as Normally closed, sinking the ground from the parallel port. Once that ground point is severed (switch unplugged or wire cut), it becomes an open circuit.

For example, the G540 has an internal optical transistor (Optocoupler which has an LED that operates a transistor). The ground point, or the cathode side of the LED, is connected to ground, the LED turns on which turns on the Transistor which activates the software to say the limit switch is on. In this case, this would be a normally closed switch. The Limit switch would go between the LED's cathode and the ground point, almost as if you placed a mechanical switch there to complete the closed circuit. This is idea for a perfect SAFELY operated machine. Because if the wiring for the limit switch is accidentally cut or has become unplugged, it would stop the LED from emitting light, thus turning off the transistor, notifying the software program that the circuit is open. So in this case, Mach 3 would have to be configured as a Normally Closed (NC) switch operation.

The switches I have designed, can be configured for both NO or NC operation with the help of a combination of logic gates and optoMOS (same as Optocoupler but uses a mosFET instead of Transistor).

Hope that helps.

[justCNCit]

Hello, after struggling for a couple days on this I followed this article to success today:

https://electronics.stackexchange.co...el-port-inputs

Requirement was a common ground for both circuits. Signals register fine in Mach 3. I am using the G540 but to my knowledge it should ignore unused pins. I have a 4 axis machine and have had problems with maintaining maching position in between tool changes. I make wood signs and based on dial indicators, the motors wander on startup (10+ hour tool paths sometimes) and even a 0.002" change seems to muck up the work.

Wanted to get a proper breakout board as well but have to generate work before making any purchases and shipping to Canada is very expensive even though CNC4PC has some nice stuff. Using a PC for control so a solid +5v from the parallel port isn't an issue. But beginning to see the merits of using USB although I have a second parallel port card.

[x2df]

There's really no need to get a 'proper breakout board'. That G540 is an excellent breakout board. Only reason to upgrade or get better is if you upgrade your machine and start running bigger motors.

[justCNCit]

you have to be kidding me. Thanks for the info, that saves me some money today.

Another question on the Hall Effect switches, is that Mach only seems to pickup once the switch has turned on and then off. Is the hall effect still repeatable and accurate being used like that? I think Romano called this hysteresis, or is this some random value of field distance. Thank you

[ger21]

That's how Mach3 works when homing. It moves towards the switch until it triggers, then backs off until the switch opens. The opening point is your home position.

[justCNCit]

What I don't understand is when homing, you hit the switch and the DRO goes to zero without over shooting. How is that possible? you would think it has to ramp down and would end up a little in the negative, but no stepper is going to dead stop from normal velocity to zero.

When connecting from inputs to ground, what common digital ground is used on the G540 breakout?

[ger21]

It zeroes the DRO while backing off the switch, when the switch opens. Not when it hits the switch.

[john-100]

Hi Shawn,

what HAL effect switches are you using ?

if your using switches like the SS441 that have normally open NPN outputs you can connect them in parallel
to one of the G540 inputs

if they have their own LED indicators you may find its better to connect them to a 12V supply
with the G540 input circuit being connected to its own +12V supply - see diagram for details



John

[justCNCit]

SS441. I am not sure of that wiring diagram, using the ones previously posted the wiring and inputs now work. But my Y axis and A axis are slaved and not homing together. I'm sure the question gets asked a lot how to configure for that.

[justCNCit]

Ok so the Diagnostics screen did not show movement on A axis when simulating so that threw me off. But the homing is working now.

The repeatability posted on the first couple pages of this thread seemed really good but using a dial indicator on my setup it looks like +/-0.002" which isn't that great is there anything can be done about that?