HAL Examples
Stepper motor basic example
# Joint 0 setup
setp remora.joint.0.scale [JOINT_0]SCALE
setp remora.joint.0.maxaccel [JOINT_0]STEPGEN_MAXACCEL
net xpos-cmd <= joint.0.motor-pos-cmd => remora.joint.0.pos-cmd
net j0pos-fb <= remora.joint.0.pos-fb => joint.0.motor-pos-fb
net j0enable <= joint.0.amp-enable-out => remora.joint.0.enable
This is a simple hal configuration for basic position mode stepgen
Note: sections with labels such as “[JOINT_0]xxxx” means the value is found in the Linuxcnc ini file under [JOINT_0]
For further refinement of your stepper configuration, or if you are having issues with stepper position, it is recomended to add these sections to your Linuxcnc hal/ini file. These represent values for the internal stepgenerator and can be used to smooth out motion.
setp remora.joint.0.pgain [JOINT_0]P_GAIN
setp remora.joint.0.ff1gain [JOINT_0]FF1_GAIN
setp remora.joint.0.deadband [JOINT_0]DEADBAND
Stepper motor Closed Loop example
# remora joint control to velocity mode
loadrt remora ctrl_type=v
# load the PRU encoder module
loadrt PRUencoder names=encoderJ0
# load pid controller for joint0
loadrt pid names=j0pid
# add PRUencoder and PID to funtions
addf PRUencoder.capture-position servo-thread
addf j0pid.do-pid-calcs servo-thread
# Joint 0 setup
setp remora.joint.0.scale [JOINT_0]SCALE
setp remora.joint.0.maxaccel [JOINT_0]STEPGEN_MAXACCEL
setp encoderJ0.position-scale [JOINT_0_ENCODER]ENCODER_SCALE
net j0enable <= joint.0.amp-enable-out => remora.joint.0.enable
net j0enable => j0pid.enable
net encoderJ0-count => encoderJ0.raw_count
net j0pos-fb <= encoderJ0.position => j0pid.feedback
net j0pos-fb => joint.0.motor-pos-fb
net j0pos-cmd <= joint.0.motor-pos-cmd => j0pid.command
net j0pid-output <= j0pid.output => remora.joint.0.vel-cmd
setp j0pid.Pgain [JOINT_0]P
setp j0pid.Igain [JOINT_0]I
setp j0pid.Dgain [JOINT_0]D
setp j0pid.bias [JOINT_0]BIAS
setp j0pid.FF0 [JOINT_0]FF0
setp j0pid.FF1 [JOINT_0]FF1
setp j0pid.FF2 [JOINT_0]FF2
setp j0pid.deadband [JOINT_0]DEADBAND
# Remora Process Value (PV) feedbacks
# link the encoder PV to the config.txt
net encoderJ0-count <= remora.PV.0
Note: sections with labels such as “[JOINT_0]xxxx” means the value is found in the Linuxcnc ini file under [JOINT_0]
The example above is for setting up a stepgen joint with velocity mode to run a closed loop stepper motor, please refer to the example configuration under linuxcnc/configs/remora/remora-closed-loop
PWM to 0-10v spindle control simple
#spindle DAC 0-10 control
loadrt scale count=1
addf scale.0 servo-thread
setp scale.0.gain 1 #this will make m3 s1000 give 100% output and m3 s100 10%
net spindle-speed-scale spindle.0.speed-out => scale.0.in
net spindle-speed-abs scale.0.out => abs.0.in
net spindle-speed-DAC abs.0.out => remora.SP.3
In the above example we create a scale and give it a value of 1
then we link the spindle speed to the scale input
Then we must pass the scale value into a abs as the spindle value can go negative. linux cnc uses negative to define spindle direction and we need to avoid this as the abs will always return a positive number.
Lastly we take the abs out and link it to the remora.sp.3
remora needs a value between 0-100 for the pwm gen.
PWM to 0-10v spindle control with inverted lincurve compensation.
#spindle DAC 0-10 control
loadrt lincurve personality=9
addf lincurve.0 servo-thread
loadrt scale count=1
addf scale.0 servo-thread
setp scale.0.gain 1 #this will make m3 s1000 give 100% output and m3 s100 10%
net spindle-speed-scale spindle.0.speed-out => scale.0.in
net spindle-speed-abs scale.0.out => abs.0.in
net spindle-speed-DAC abs.0.out => lincurve.0.in
#Lincurve compensation
setp lincurve.0.x-val-00 10
setp lincurve.0.y-val-00 100
setp lincurve.0.x-val-01 100
setp lincurve.0.y-val-01 98
setp lincurve.0.x-val-02 200
setp lincurve.0.y-val-02 90
setp lincurve.0.x-val-03 300
setp lincurve.0.y-val-03 81
setp lincurve.0.x-val-04 400
setp lincurve.0.y-val-04 69
setp lincurve.0.x-val-05 500
setp lincurve.0.y-val-05 59
setp lincurve.0.x-val-06 600
setp lincurve.0.y-val-06 48.6
setp lincurve.0.x-val-07 700
setp lincurve.0.y-val-07 39.6
setp lincurve.0.x-val-08 800
setp lincurve.0.y-val-08 29.9
setp lincurve.0.x-val-08 900
setp lincurve.0.y-val-08 20.8
setp lincurve.0.x-val-08 1000
setp lincurve.0.y-val-08 12.6
net spindle-corrected lincurve.0.out => remora.SP.3
This is almost the exact same as above but adds a lincurve component to fix for the non linear PWM to 0-10v control board selected, it also fixes a problem of the cnc break out board logic being reversed.
Such that without the lincurve 0%pwm would give out 10V(max spindle speed) and 100% pwm would give out 0V
We take the abs out and pass it into lincurve then the table in lincurve takes a value X and replaces it with value Y and scale any value between the points.
in the above any value between 0-10 for spindle speed gives 100 as the output thus the logic is inverted
in the above any value between 1000 or more for spindle speed gives 12.6
For more info about lincurve
This was tuned via a scope watching the values and making the table such that the output would be roughly linear.
Spindle control and coolant signal outputs
# outputs
net coolant-flood <= iocontrol.0.coolant-flood
net spindle-on => remora.output.00
net spindle-ccw => remora.output.01
net coolant-flood => remora.output.02
QEI Encoder without index
# Initialize the encoder (spindle)
loadrt PRUencoder names=encoder.0
addf PRUencoder.capture-position servo-thread
setp encoder.0.position-scale 1200.000000 #6
# connect the hal encoder to linuxcnc
net encoder-count <= remora.PV.2 => encoder.0.raw_count
This example we add the encoder module to the linux cnc servo thread
Then define/set the encoder with its pulse per revolution, example: 300pulse per rev encoder x4 for being a quadrature encoder equals 1200.
Then we link the “encoder-count” to the remora PV value and pass it all into encoder.0.raw_count (the PV value will be what ever you set in the config tool/file)
QEI Encoder with index
# Initialize the encoder (spindle)
loadrt PRUencoder names=encoder.0
addf PRUencoder.capture-position servo-thread
setp encoder.0.position-scale 1200.000000 #6
# connect the hal encoder to linuxcnc
net encoder-count <= remora.PV.2 => encoder.0.raw_count
net encoder-phaseZ <= remora.input.07 => encoder.0.phase-Z
This example we add the encoder module to the linux cnc servo thread
Then define/set the encoder with its pulse per revolution, example: 300pulse per rev encoder x4 for being a quadrature encoder equals 1200.
Then we link the “encoder-count” to the remora PV value and pass it all into encoder.0.raw_count (the PV value will be what ever you set in the config tool/file)
Finally we link encoder-phaseZ to the remora input that has the index pulse connected and pass it to encoder.0.phase-Z.
Endstops + home switches
# end-stops
net X-min remora.input.00 => joint.0.home-sw-in joint.0.neg-lim-sw-in
net Y-min remora.input.02 => joint.1.home-sw-in joint.1.neg-lim-sw-in
net Z-min remora.input.04 => joint.2.home-sw-in joint.2.neg-lim-sw-in
In the above example we are sending the value of the input to both the home-sw-in and neg-lim-sw-in
The advantage to this is we can save on pins and simplify the machine wiring