SKR 3 - Spindle Sync

[CBR900cc]

Hello, I'm retrofitting an old lathe, it as encoder onboard and I've wired everything to SKR3, but encoder not reading, this is my platformio env:

`[env:btt_skr_30_h723_tmc5160]
board = generic_stm32h723vg
board_build.ldscript = STM32H723VGTX_FLASH.ld

build_flags =
${common.build_flags}
${usb_h723.build_flags}
;${sdcard.build_flags} ; disattivalo per test flash
-D BOARD_BTT_SKR_30
-D HSE_VALUE=25000000
-D DRIVER_SPINDLE_ENABLE=7 ; 1|2|4 = SPINDLE_ENA|SPINDLE_DIR|SPINDLE_PWM
-D VARIABLE_SPINDLE
-D SPINDLE_ENCODER_ENABLE=1
-D SPINDLE_SYNC_ENABLE=1
-D SPINDLE_ENCODER_USE_QEI=1
-D SPINDLE_SYNC_USE_QEI=1
-D SPINDLE_ENCODER_CLK=1
-D PROBE_ENABLE=0
-D SPINDLE0_ENABLE=11
-D N_SPINDLE=1
-D MY_MACHINE
-I Inc
-include Inc/my_machine.h

lib_deps =
${common_h723.lib_deps}
${usb_h723.lib_deps}
;${sdcard.lib_deps}
motors

lib_extra_dirs =
${common.lib_extra_dirs}
${usb_h723.lib_extra_dirs}
;${sdcard.lib_extra_dirs}

upload_protocol = dfu
monitor_speed = 115200
monitor_echo = yes
`

old encoder has 5 wires: 5v, gnd, out1, index, out2

[terjeio]

You have modified the board map and added pin mappings for the encoder?

BTW the H7 driver is by @dresco, I do not have any H7 boards available at the time.

[CBR900cc]

yes, pin mapped, there is some thing to check if spindle sync is really active by grbl command, like $sync?

[terjeio]

$I output contains SS in the NEWOPT string when enabled and the $PINS output should contain the encoder pins.
The related settings will also become available. $38 has to be set > 0 to enable encoder input which is required for spindle sync.

[CBR900cc]

ok, these settings are available and I've setted $38 to 1

[terjeio]

Ok, you should then be able to use the $SD command to output encoder data, pulse count, index count, error count and angular position. Use $SR to reset the data.

[CBR900cc]

ok, no one input

[dresco]

I've bench tested on my own prototype board, so the basic functionality should be working on the H7 driver. The commit where support was updated is here.

You'll note that there are a couple of clock input options, and I did hardcode an internal pullup on the spindle sync input (not optimal - but don't think there was a setting for this & I never got around to asking).

Can you share your pin mappings etc. I also have an SKR3 here, so can have a look..

[CBR900cc]

I'm using PB4 for SPINDLE_PULSE_PIN and PD7 for SPINDLE_INDEX_PIN
if can help, my encoder is 1250ppr and goes to gnd when pulsing

[terjeio]

When testing with a Nucleo 144 I get stable RPM from my simulator with these changes to the board map:

#if !SPINDLE_ENCODER_ENABLE && (COOLANT_ENABLE & COOLANT_MIST)
#define COOLANT_MIST_PORT           AUXOUTPUT4_PORT
#define COOLANT_MIST_PIN            AUXOUTPUT4_PIN
#endif

#if SPINDLE_ENCODER_ENABLE
#define SPINDLE_INDEX_PORT          GPIOD
#define SPINDLE_INDEX_PIN           7
#define SPINDLE_PULSE_PORT          GPIOB
#define SPINDLE_PULSE_PIN           4
#define SPINDLE_ENCODER_CLK         1
#endif

$SD output shows both pulse and index counts:

[SPINDLEENCODER:10,12190,1,10.114]

AFAIKT PD7 and PB4 is routed to U7 inputs, did you solder encoder wires to its pins?

[dresco]

When testing with a Nucleo 144 I get stable RPM from my simulator with these changes to the board map

Shall I add to the default Nucleo map?

[terjeio]

Shall I add to the default Nucleo map?

I modified the SKR 3 board map to use for the Nucleo for somewhat realistic testing. If no conflicts in the default map it could be nice to add?

[CBR900cc]

ok, using PC6 and PD14, rotation is recognized but is very oscillating, and when I try PID Tuner, after pressing "Get Data" (IOSender), console print:

error:20 - Unsupported or invalid g-code command found in block.

Any suggestion?

[terjeio]

This works fine for me too, these pins are available on a link header for the E0 motor (dir and chip select)?

error:20 - Unsupported or invalid g-code command found in block.

Was lathe mode enabled? $31=2

[CBR900cc]

yes! $31 = 2

Now I'm using PD2 -> Pulse, PB14 -> Index, but rpm oscillating continuosly... around 100/125 rpm

[terjeio]

Testing with PD2 and PD14 (PB14 is not available on the Adrduino headers - I have not soldered CN11/CN12 headers yet) I again get stable output:

<Idle|MPos:0.000,0.000,0.000|Bf:100,1023|FS:0,200,197|Pn:XYZP>
<Idle|MPos:0.000,0.000,0.000|Bf:100,1023|FS:0,200,197|Pn:XYZP>
<Idle|MPos:0.000,0.000,0.000|Bf:100,1023|FS:0,200,197|Pn:XYZP>
<Idle|MPos:0.000,0.000,0.000|Bf:100,1023|FS:0,200,197|Pn:XYZP>
<Idle|MPos:0.000,0.000,0.000|Bf:100,1023|FS:0,200,197|Pn:XYZP>
<Idle|MPos:0.000,0.000,0.000|Bf:100,1023|FS:0,200,197|Pn:XYZP>
<Idle|MPos:0.000,0.000,0.000|Bf:100,1023|FS:0,200,197|Pn:XYZP>
<Idle|MPos:0.000,0.000,0.000|Bf:100,1023|FS:0,220,217|Pn:XYZP|Ov:100,100,110|A:SE>
<Idle|MPos:0.000,0.000,0.000|Bf:100,1023|FS:0,220,217|Pn:XYZP>
<Idle|MPos:0.000,0.000,0.000|Bf:100,1023|FS:0,220,217|Pn:XYZP|WCO:0.000,0.000,0.000>
<Idle|MPos:0.000,0.000,0.000|Bf:100,1023|FS:0,220,216|Pn:XYZP>
<Idle|MPos:0.000,0.000,0.000|Bf:100,1023|FS:0,220,217|Pn:XYZP>
<Idle|MPos:0.000,0.000,0.000|Bf:100,1023|FS:0,220,217|Pn:XYZP>
<Idle|MPos:0.000,0.000,0.000|Bf:100,1023|FS:0,220,217|Pn:XYZP>
<Idle|MPos:0.000,0.000,0.000|Bf:100,1023|FS:0,220,217|Pn:XYZP>
<Idle|MPos:0.000,0.000,0.000|Bf:100,1023|FS:0,220,217|Pn:XYZP>
<Idle|MPos:0.000,0.000,0.000|Bf:100,1023|FS:0,220,217|Pn:XYZP>

The 197 -> 217 step is due to a 10% RPM override.

So, IMO, either your input signal is noisy or unstable. Don't know if I should average the RPM result over several calls. What cannot be averaged is the angular position which is used for the PID loop.

[CBR900cc]

what's strange is that if I turn everything on and disconnect the encoder shaft from the lathe shaft, $SD doesn't give me any counts, so there's no interference... I think!

[terjeio]

Bad encoder then? It would be helpful if you could scope the signals?

[CBR900cc]

@terjeio @dresco please help me, I need to solve as soon as possible, i can pay for a faster help if you need!

[dresco]

Am using my own prototype board - map here, pins are PG14 & PB4.

If you turn the spindle manually, does your $SD output change as expected?

[CBR900cc]

$sd change not good, now I'm replacing encoder + wiring, update you soon
But is correct $sd show numbers update simply with cable connected (motor off!) but no update with cable disconnected (motor off)?

[CBR900cc]

uhm...... with cable connected and VFD ON (motor off) $SD change, but with VFD OFF(motor off) $SD stay unchanged!

[terjeio]

The F7 and H7 uses (or may use) incorrect clock settings (prescaler) for the RPM timer that may result in incorrect RPM returned.
I have fixed the F7 code (copied over from the F4 driver) and will commit it later. When testing with my simulator the RPM reported is stable regardless so this "bug" is not the source of instability. The F4 code also supports 16 bit RPM timers via counting overflows - I'll copy this code over as well.

One way to check that the $SD output is approximately correct is to run the spindle for e.g. 30 seconds and check that returned values are within range. At 60 RPM the index count should be around 30 depending on the time taken to accelerate/decelerate the spindle. The pulse count should be close to the index count multiplied with the actual PPR.

[CBR900cc]

ok, thank you, I think there are high noise from vfd, working hard to solve

[CBR900cc]

@terjeio @dresco I've solved noise issue, but rpm are oscillating continuosly, I've manually applied fix from F7 code (copied over from the F4 driver) like you but issue no resolved, and I'm not able to threading! Can you help me? please I need to solve, is possible to contact your with instant messaging?
thank you

[dresco]

PG14 for index, PB4 for pulse (dedicated encoder inputs on my own board)

// Spindle encoder pins (index pin must be interrupt capable).
#if SPINDLE_ENCODER_ENABLE
#define SPINDLE_INDEX_PORT          GPIOG
#define SPINDLE_INDEX_PIN           14
#define SPINDLE_PULSE_PORT          GPIOB
#define SPINDLE_PULSE_PIN           4
#define SPINDLE_ENCODER_CLK         1
#endif

[CBR900cc]

can you check if pin I'm using have some issue? or anything else?
tomorrow with your pins, if there are in my board

[dresco]

While setting this back up, have remembered my original testing didn't go to plan. I couldn't get the stepper spindle to work with the encoder configured (was getting a hard fault when starting the spindle), so had been testing using a stepper on a spare axis to verify encoder counts. (In fact this seems worse now, can't start a stepper spindle at all, even without encoder configuration).

Have updated the H7 code with the latest changes (will push to GitHub shortly), and can confirm the encoder counts are still as expected for me. Testing with the stepper/encoder driven from the A axis.

Afraid I'm not able to verify your pins, as they are in use elsewhere on my board. However, am confident I would have tested both timer modes (TI1FP1 and ETR pins) on a dev board when I was adding the code.

I have just noticed your pulse pin (PD2) is also used by the SDMMC peripheral, have you disabled SD card support in your build configuration?

[CBR900cc]

in my build I've commented these lines in platformio.ini:
build_flags =
${common.build_flags}
${usb_h723.build_flags}
;${sdcard.build_flags}

lib_deps =
${common_h723.lib_deps}
${usb_h723.lib_deps}
;${sdcard.lib_deps}

lib_extra_dirs =
${common.lib_extra_dirs}
${usb_h723.lib_extra_dirs}
;${sdcard.lib_extra_dirs}

I think it is disabled!

[dresco]

I think it is disabled!

Yes, should be.
SD will be present in the NEWOPT line of the $I response if enabled..

[CBR900cc]

thank you, for the moment I've been edited source for using simply INDEX and not PULSE for sync, now my lathe thread decent and rpm read is good. Waiting for your tests, please update me asap, really thanks for you job, if you accept I want to offer you a "pizza"!

[dresco]

I've got my stepper spindle working now. The encoder counts look correct, but the encoder feedback doesn't seem to be having any impact on spindle speed. For example I get the same spindle speed (read from a tachometer) whether $38 is correctly set to 360PPR, or changed to something incorrect.

Not sure whether I'm still missing a setting, or whether this is not supported for a stepper spindle?

[CBR900cc]

I don't know, in my case, editing $38 multiplier of rpms, change! but now I'm working with simple index, without pulse... my lathe have 8kw spindle motor, don't think it can lose rpms. I've ordered teensy 4.1 hoping to solve everything and return back to index + pulse... Can you implement a sync only using index??