3 Achs Fräse mit MESA 7C80 und Raspi 4

I don't see any obvious issues with the hal /ini files, other than
the facts that the PWM rate was set to 400 Hz which is too low.
It would not prevent the analog output from working,  it would
just cause more output ripple than desired.

What is the voltage between SPINDLE+ and SPINDLE- ?

What is the result of

1. Starting LinuxCNC.

2. Setting the spindle on and the speed to 1/2 of full scale (12000 RPM)

3. Checking all the spindle signals with

halcmd show signal spin

Hello,

Please excuse my crashing into this thread. I've found it very useful so far and managed to set up 6 out of 7 parts of my 30-year-old Gravograph Unica that I'm trying to convert to LinuxCNC running on a Raspberry Pi with a Mesa 7C80.

What's working fine so far are the 3 steppers and corresponding home switches X, Y & Z.

But: The spindle won't turn on.
I'd like to control it via PWM and as far as I can tell there should be PWM output on pin 2 of TB5 of the 7C80.
There's no useable output there, and I'm not sure where to search and what to do next ...

If there's any chance you could have a look at my .hal and .ini files, that would be very much appreciated
I also included the output of the terminal from where LinuxCNC was launched, and the output of "halcmd show signal spin".
Voltage between SINDLE+ and SPINDLE- seems to be just noise or in the mV-Magnitude.

Thank you for reading and best regards,
Erik
captain-panda

 
 
 
 

You must apply an external voltage (5 to 15 VDC)
between SPINDLE+ and SPINDLE-. This voltage typically
comes from the VFD. (the potentiometer supply) It is best
that this comes from the VFD so the you do not introduce
VFD switching  noise into the rest of the system.

The output voltage on SPINDLE OUT will vary from SPINDLE-
to SPINDLE+ as  the PWM duty cycle varies from 0 to 100%
(0 RPM to full RPM)

Thank you PCW!

Not sure I understand that fully.
There's no VFD in my setup - what I'm looking for is a generic PWM signal - pulses - that I want to feed to this spindle driver board:

www.mikroe.com/pwm-driver-click

The board needs 5V power supply itself, which I currently take from the 7C80.
Now, if I hook up SINDLE- to GND and SPINDLE+ to +5V, will there be 5V pulses on SPINDLE OUT?

The spindle output is _not_ a PWM output but rather
an isolated analog output used to replace the potentiometer
of a VFD.

If you need a 5V PWM signal, you would need firmware
that includes a pwmgen with an output on a 5V pin

7c801p_5abobd.bit

Is one, this replaces STEP5 with a PWM output

 

Okay!
Thank you for this clarification.
I'm considering changing my control concept rather than the firmware.
The larger Gravograph machines have AC spindle motors anyway, and I can use the analog signal for those as well ...
Would this other firmware only turn STEP5 into a PWM output, or affect other functions and/or pinout of the 7C80 as well?

The firmware changes STEP5 to PWM and DIR5 to GPIO
it also sets up the parallel expansion port (P1) to interface
with a standard 5 Axis breakout. This should not make any
operational differences.

Hallo.

Meine 3 Achs Fräse läuft jetzt. Homing funktioniert. Referenzschalter sind eingebaut und funktionieren. Handrad funktioniert (fast). Jetzt möchte ich noch, dass spindle-at-speed mit einem Eingang verknüpft wird, der gesetzt wird (high) wenn die Zielfrequenz der Spindel am FU anliegt. Wie mache ich das? Mein FU schaltet ein Relais durch und damit liegt auf einem Eingang 24V an. Das Signal kommt an und der Eingang wird auch geschaltet. Nur wie mache ich jetzt die Verknüpfung zu spindle-at-speed?

Hat mir da jemand einen tipp?

LG

Hans Peter

Hallo Aciera

Danke für deinen Tipp, aber der funktioniert leider nicht. Das habe ich auch schon so versucht. Aber wenn ich das so in die HAL eingebe, dann ist zumindest das LED am Dragon HD Screen für spindel at speed sofort nach dem Absetzen des MDI Kommandos "M3 S24000" an. Die Spindel braucht aber 5 Sekunden für den Hochlauf. Der Inputpin geht auf High, wenn die Zielfrequenz erreicht ist. Das spindle at speed ist von dem Zustand des Input Pins komplett unbeeindruckt.

LG

Hans Peter