noel20 pisze:A może w linuxie da się zmienić, żeby zmieniając prędkość wrzeciona w programie zmieniała się częstotliwość, a nie wypełnienie?

linuxcnc-dev/linuxcnc-dev/src/hal/components$ ls *.c
at_pid.c    encoder_ratio.c  mux_generic.c  siggen.c        supply.c
boss_plc.c  freqgen.c        pid.c          sim_encoder.c   threads.c
counter.c   lcd.c            pwmgen.c       stepgen.c       watchdog.c
debounce.c  matrix_kb.c      sampler.c      streamer.c      weighted_sum.c
encoder.c   modmath.c        sampler_usr.c  streamer_usr.c

'siggen.c', is a HAL component that generates square, triangle, sine, cosine, and sawtooth waves. I expect that it will mostly be used for testing. It is a realtime component.

It supports any number of signal generators, as set by the insmod parameter 'num_chan'. Alternatively,use the names= specifier and a list of unique names separated by commas. The names= and num_chan= specifiers are mututally exclusive.

Each generator has a number of pins and parameters, whose names begin with 'siggen.x.', where 'x' is the generator number.
Generator numbers start at zero.

Each generator is controlled by three pins. 'frequency' sets the frequency in Hertz. 'amplitude' sets the peak amplitude, and 'offset' sets the DC offset. For example, if 'amplitude' is 1.0 and 'offset' is 0.0, the outputs will swing from -1.0 to +1.0. If 'amplitude' is 2.5 and 'offset' is 10.0, then the outputs will swing from 7.5 to 12.5.

There are six output pins: 'square', 'triangle', 'sine', 'cosine', 'clock', and 'sawtooth'. All six run at the same frequency, amplitude, and offset.

This component exports one function per signal generator, called 'siggen.x.update'. It is a floating point function.

'stepgen.c', is a HAL component that provides software based step pulse generation. The maximum step rate will depend on the speed of the PC, but is expected to exceed 5KHz for even the slowest computers, and may reach 25KHz on fast ones. It is a realtime component.

It supports up to 16 pulse generators. Each generator can produce several types of outputs in addition to step/dir, including quadrature, half- and full-step unipolar and bipolar, three phase,
and five phase. A 32 bit feedback value is provided indicating the current position of the motor in counts (assuming no lost steps), and a floating point feedback in user specified position units is also provided.

'freqgen.c', is a HAL component that generates step pulses at a specific frequency in software. The maximum step rate will depend on the speed on the PC, but is expected to exceed 1KHz for even the slowest computers, and may reach 10KHz on fast ones. It is a realtime component.

Note that this is _not_ the preferred step pulse generator for EMC2. This module simply generates a frequency (velocity). A separate PID or other loop is needed to turn EMC's position commands into velocity commands, and the PID loop needs to be tuned, which adds unneccessary complexity to the machine setup. For EMC and other applications that use position instead of velocity commands, the component "stepgen" is preferred. It contains a built in, pre-tuned position to velocity converter. This module is provided only for special cases where it is more appropriate.

mc2kwacz pisze:Powtarzam, że są tu inne źródła błędów, konsekwentnie ignorowane, i nie ma nad nimi kontroli.

Mądrej głowie dość dwie słowie

mc2kwacz pisze:Najprostszy układ z transoptorem będzie bardziej nieliniowy ale za to zdecydowanie bardziej powtarzalna

mc2kwacz pisze:Chodzi o to, żeby najpierw się nauczyć i zrozumieć a potem zabierać za robotę.

mc2kwacz pisze:Kwantyzacja czyli rozdzielczość sygnału cyfrowego to jego minimalna możliwa zmiana a nie stosunek czegoś do czegoś.

noel20 pisze:Nie wiele z tego zrozumiałem
A o co chodzi z trybem regulacji gęstości?

tuxcnc pisze:Otóż :

Cytat:

Because software-generated PWM uses a fairly slow timebase (several to many microseconds), it has limited resolution. For example, if make-pulses is called at a 20KHz rate, and pwm-freq is 2KHz, there are only 10 possible duty cycles.

( http://linuxcnc.org/docs/...9/pwmgen.9.html )

This file, 'pwmgen.c', is a HAL component that generates Pulse Width Modulation or Pulse Density Modulation signals in software. Since the timing granularity of a software based scheme is rather large compared to a hardware, either the output frequency, or the resolution, or both, will be less than expected from hardware implementations.

The driver exports two functions. 'pwmgen.make-pulses', is responsible for actually generating the PWM/PDM signals. It must be executed in a fast thread to reduce pulse jitter and improve resolution. The other function, pwmgen.update, is normally called from a much slower thread. It reads the command and sets internal variables used by 'pwm.make-pulses'. 'update' uses floating point, 'make-pulses' does not.

loadrt pwmgen output_type=0
addf pwmgen.make-pulses base-thread
addf pwmgen.update servo-thread
net spindle-cmd <= motion.spindle-speed-out => pwmgen.0.value
net spindle-enable <= motion.spindle-on => pwmgen.0.enable
net spindle-pwm <= pwmgen.0.pwm
setp pwmgen.0.pwm-freq 1000.0
setp pwmgen.0.scale 8877.77777778
setp pwmgen.0.offset 0.04887359199
setp pwmgen.0.dither-pwm true
net spindle-pwm => parport.0.pin-01-out

BASE_PERIOD = 16666
SERVO_PERIOD = 1000000

loadrt [EMCMOT]EMCMOT base_period_nsec=[EMCMOT]BASE_PERIOD servo_period_nsec=[EMCMOT]SERVO_PERIOD num_joints=[TRAJ]AXES