Cramps board FAULT pins

[klemenz...@gmail.com]

Hi!

I have connected closed loop steppers (3 of them) to cramps that resides on beaglebone that runs machinekit, and this closed loop steper drivers have FAULT- and FAULT+ pin.

FAULT + pin goes to GND when closed loop driver cannot push motor in demanded position.

Is it possible to connect this fault pin to some fault pin on cramps (or somehow connect them to eStop)? I was looking cramps pdf schematics, but cannot find such pin.

[Charles Steinkuehler]

I'd recommend just using one of the digital I/O pins unless you need
all six limit switches on P502 and the 4 spare/SPI pins on P503. Add
a signal to your HAL file and tie it to the amp-fault-in signal(s) of
the motion component.

If you really want to wire your fault signal into the ESTOP chain, you
can use a circuit similar to what I have already on the board instead
of a simple jumper (or in series with a physical ESTOP switch if
you've got one).

Something similar to the R301/Q303 circuit in the ESTOP chain on the
CRAMPS board should do what you want:

* You probably want a pull-up resistor on the FAULT+ line (similar to
R301). The pull-up voltage and the resistance will depend on the
characteristics of your FAULT+ output. Make sure you do not exceed
the maximum Vgs of the FET (usually 15-20V).

* The FET gate should be tied to your FAULT+ signal. The FET will
conduct when FAULT+ is high, and will not conduct when FAULT+ is low.

* The FET source should be tied to the low side of the ESTOP chain
(P302 pin 2)

* The FET drain should be tied to the high side of the ESTOP chain
(P302 pin 1)

--
Charles Steinkuehler
cha...@steinkuehler.net