Re: Under the pole limit exceeded while parking

Howard Dutton

Guessing you're exceeding the AXIS1_LIMIT_MIN (Config.h mainly but runtime via website with newer versions) but watch out for the horizon limit also (runtime only.)

#define AXIS1_LIMIT_MIN              -190 //   -180, n. Where n= -90..-270 (degrees.) Minimum "Hour Angle" for Eq modes.      Adjust
                                          //         n. Where n=-180..-360 (degrees.) Minimum Azimuth for AltAzm mode.
#define AXIS1_LIMIT_MAX               180 //    180, n. Where n=  90.. 270 (degrees.) Maximum "Hour Angle" for Eq modes.      Adjust
                                          //         n. Where n= 180.. 360 (degrees.) Maximum Azimuth for AltAzm mode.

This is what the situation looks like, the solid red line shows MIN limit (changed to -190 degrees) and the thin dashed line is the MAX limit (still 180 degrees and not active on this pier side.)

Re: MKS GEN-L V2.1 TMC5160

Howard Dutton

Pretty sure shunts go in the green pin headers (4 under each driver) for SPI mode.

Re: MKS GEN-L V2.1 TMC5160


Thanks for your answer, so it should be very easy!

Re: Two problems with 3.16

Mark Christensen


Thanks, I'll file it for future reference. Since I was able to get 4.24 working without the two funnies seen in 3.16 I don't see the need. The Configs were the same.


Re: Under the pole limit exceeded while parking

Pablo Lewin

Ok now that the wind died down (winds of up to 50 kts ) I tried it again and this time by adjusting the meridian limits I was able to get the RA axis to move to the park position BUT as soon as the declination axis got close to horizontal that's when the under the pole limit exceeded error was triggered and the mount stopped but once I moved the declination axis back up again away from horizontal and towards polaris the mount reset itself

So the problem lies with th Declination limit and NOT with the meridian limits..I also unchecked the auto meridian flip just to experiment but I doubt this had any bearing with the dec limit problem

The question now: How do I disable or change the declination limit? Is there a way to do it through the app or is this something that has to be programmed?



Re: MKS GEN-L V2.1 TMC5160


Should be no jumpers/shunts underneath the stepper drivers for SPI mode.

Re: Can i lower the goto speed to 0.1x

Mike Ahner

On Sun, Jan 23, 2022 at 07:08 PM, apo wrote:
especially at start run so cause motor stalling
You can change the ramp up speed and the stop speed with the settings in this post from Howard. Maybe if you slow down the startup even more, the motor won't stall.

Re: Can i lower the goto speed to 0.1x


I use 2 LV8729 as stepper driver. RA set to 0.5A and 0.4A for DEC. I use 12V DC 5A power supply. Manual slewing at 8x to 16x is working fine on both axis with sufficent torrque. Just can’t turn the Goto speed slower, especially at start run so cause motor  stalling .

Microstepping is not the issue on this case.

Tracking also working fine at Sidereal rate.

The two motor are original on old Astro-Physics AP900 QMDC version. Can turn motors with the knobs if there is no power.


Re: Posicionamento errado para objetos #arduino #EQ5

Howard Dutton

On Sun, Jan 23, 2022 at 04:36 PM, Fabio wrote:
#define AXIS2_MICROSTEPS_GOTO_2      // Axis2 (Dec/Alt): Default _OFF, Optional microstep mode used during gotos
Should be...

#define AXIS2_MICROSTEPS_GOTO 2      // Axis2 (Dec/Alt): Default _OFF, Optional microstep mode used during gotos

..and that's an ancient version of OnStep, should use release-4.24.

Re: CGEM w/internal FYSETC S6 V2.0 #celestron #fysetc


I'd love some help on this, I already have the ftsec board, so I would just need the other parts and how to install belts and gears.  Let me know if you have more photos or information. Thank you

Re: CGEM w/internal FYSETC S6 V2.0 #celestron #fysetc


Sean, any way you could show me how you added the belts and gears? This is something I'd love to do, I already own the ftsec board and would just need to pick up the D1 mini V4 and belts, gears, and steppers. Have you done any imaging with this? What does your RMS error look like, if you have?



Take care,



Posicionamento errado para objetos #arduino #EQ5


Oi pessoal! Preciso de uma ajuda pois sou iniciante, infelizmente não sei especificações detalhadas da placa do onstep que veio junto a uma montagem EQ5 que comprei. O problema é que seja quando peço para fazer o alinhamento (estrela) pelo aplicativo celular ou quando envio o comando goto para qualquer objeto, os motores param MUITO antes de chegar ao destino final. Não sei o que fazer. 

Para contextualizar vocês informo as características do equipamento: 
Montagem: Eq5
Onstep: 1.8 (antigo)
02 Motores: Nema 17 
Passos: 200 (cada um deles)
Drive: DRV8825

Utilizei a planilha de configuração e alcancei os seguintes valores:
versão da planilha: 1.12
Stepper-Steps: 200 (para os dois eixos)
Micro-Steps: 32 (para os dois eixos)
GR1: 3 (para os dois eixos)
GR2: 144 (para os dois eixos)
MaxRate: 44

Essa combinação trouxe os seguintes valores:
StepsPerDegreeAxis1 = 7680.00000
StepsPerDegreeAxis2 = 7680.00000
StepsPerWormRotationAxis1 = 19200
StepsPerWormRotationAxis2 = 19200
Steps per second (in RA, Eq mounts)  = 32.0
Tracking resolution estimate (in arc-sec) = 0.469
Maximum slew rate (°/s)  = 2.96
PECBufferSize = 600
Stepper Motor shaft speeds (am ambos eixos) -> 213.1 RPM;  3.6 RPS;  0.7 kHz (full step)

Dados da minha localização:
Latitude: -13º
Longitude: +38º 28'
UTC Offset: +3h

Características do GOTO Limits: 
Horizon: -10
Overhead: 90
Meridian E: 10
Meridian W: 10

Estou usando o onstep para android como também Poth Setup para conexão ao Stellarium via ASCOM (v1.44). As conexões estão OK. Os programas reconhecem normalmente os equipamentos e consigo acompanhar por eles, porém quando o comando é enviado para os motores eles começam bem mas antes de chegarem ao destino final param. Parece que vão até a metade do caminho, por exemplo. Daí para chegar até o objeto escolhido tenho que clicar nos comandos até chegar.

A configuração presente no config.classic.h é a seguinte:

// -----------------------------------------------------------------------------------
// Configuration for legacy OnStep Classic (Mega2560 or Teensy3.x)
// *** this is for backwards compatability with older OnStep systems ***
#define Classic_ON   //  <- Turn _ON to use this configuration
#ifdef Classic_ON
// -------------------------------------------------------------------------------------------------------------------------
// ADJUST THE FOLLOWING TO CONFIGURE YOUR CONTROLLER FEATURES --------------------------------------------------------------
// Enables internal goto assist mount modeling (for Eq mounts), default=_OFF (Experimental)
// Note that Goto Assist in Sky Planetarium works even if this is off
// Default speed for Serial1 com port, Default=9600
// Mount type, default is _GEM (German Equatorial) other options are _FORK, _FORK_ALT.  _FORK switches off Meridian Flips after (1, 2 or 3 star) alignment is done.  _FORK_ALT disables Meridian Flips (1 star align.)
// _ALTAZM is for Alt/Azm mounted 'scopes (1 star align only.)
// Strict parking, default=_OFF.  Set to _ON and unparking is only allowed if successfully parked.  Otherwise unparking is allowed if at home and not parked (the Home/Reset command ":hF#" sets this state.) 
// ST4 interface on pins 47, 49, 51, 53.  Pin 47 is RA- (West), Pin 49 is Dec- (South), Pin 51 is Dec+ (North), Pin 53 is RA+ (East.)  Teensy3.x pins 24, 25, 26, 27.
// ST4_ON enables the interface.  ST4_PULLUP enables the interface and any internal pullup resistors.
// It is up to you to create an interface that meets the electrical specifications of any connected device, use at your own risk.  default=_OFF
#define ST4_OFF
// If SEPARATE_PULSE_GUIDE_RATE_ON is used the ST4 port is limited to guide rates <= 1X except when ST4_HAND_CONTROL_ON is used.
// Additionally, ST4_HAND_CONTROL_ON enables special features: Press and hold [E]+[W] buttons for > 2 seconds...  In this mode [E] decreases and [W] increases guide rates (or if tracking isn't on yet adjusts illuminated recticule brightness.)
// [S] for Sync (or Accept if in align mode.) [N] for Tracking on/off. -OR- Press and hold [N]+[S] buttons for > 2 seconds...  In this mode [E] selects prior and [W] next user catalog item.
// [N] to do a Goto to the catalog item.  [S] for Sound on/off.  The keypad returns to normal operation after 4 seconds of inactivity.  ST4_HAND_CONTROL_ON also adds a 100ms de-bounce to all button presses.
// Finally, during a goto pressing any button aborts the slew.  If meridian flip paused at home, pressing any button continues.  default=_ON
// ST4_ALTERNATE_PINS_ON moves the interface (Mega2560 only) to pins 43, 45, 47, 49.  Pin 43 is Dec- (South), Pin 45 is Dec+ (North), Pin 47 is RA- (West), Pin 49 is RA+ (East.)
// ST4_ALTERNATE_PINS_ON is required for Steve's ST4 board and is also required if the ST4 interface is to be used alongside the Arduino Ethernet Shield
// Separate pulse-guide rate so centering and guiding don't disturb each other, default=_ON
// Guide time limit (in seconds,) default=0 (no limit.)  A safety feature, some guides are started with one command and stopped with another.  
// If the stop command is never received the guide will continue forever unless this is enabled.
// RTC (Real Time Clock) support, default=_OFF. Other options: RTC_DS3234 for a DS3234 on the default SPI interface pins (and CS on pin 10, optionally wire the SQW output to the PPS pin below.)
#define RTC_OFF
// PPS use _ON or _PULLUP to enable the input and use the built-in pullup resistor.  Sense rising edge on pin 21 for optional precision clock source (GPS, for example), default=_OFF (Teensy3.x Pin 23)
// PEC sense on pin 2 or threshold value on Analog 1 (Analog 14 on Teensy3.x) use _ON or _PULLUP to enable the input and use the built-in pullup resistor, default=_OFF
// analog values range from 0 to 1023 which indicate voltages from 0-5VDC (or 0-3.3VDC) on the analog pin, for example "PEC_SENSE 600" would detect an index when the voltage exceeds 2.92V (or 1.93V)
// with either index detection method, once triggered 60s must expire before another detection can happen.  This gives time for the index magnet to pass by the detector before another cycle begins.
// Ignored on Alt/Azm mounts.
// PEC sense, rising edge (default with PEC_SENSE_STATE HIGH, use LOW for falling edge) on pin 2 (ex. PEC_SENSE_ON) ; for optional PEC index
// switch close (to ground) on pin 3 for optional limit sense (stops gotos and/or tracking), default=_OFF
// Light status LED by sink to ground (pin 9) and source +5V (pin 8), default=_ON
// _ON and OnStep keeps this illuminated to indicate that the controller is active.  When sidereal tracking this LED will rapidly flash
// Light 2nd status LED by sink to ground (pin 10), default=_OFF, must be off for Teensy3.x (pin 7)
// _ON sets this to blink at 1 sec intervals when PPS is synced
// n sets this to dimly light a polar finder reticle, for example I use STATUS_LED2_PINS 250
// The default SPI device CS is at pin 10 also, so if the SPI interface is used this must be _OFF
// Light reticule LED by sink to ground (pin 44), default=_OFF.  Defaults to pin 9 on the Teensy3.x (STATUS_LED_PINS must be _ON)
// RETICULE_LED_PINS n, where n=0 to 255 activates this feature and sets default brightness
// Sound/buzzer on pin 42, default=_OFF.  (Teensy3.x Pin 29)
// Specify frequency for a piezo speaker (for example "BUZZER 2000") or use BUZZER_ON for a piezo buzzer.
#define BUZZER_OFF
// Sound state at startup, default=_ON.
// Optionally adjust tracking rate to compensate for atmospheric refraction, default=_OFF
// can be turned on/off with the :Te# and :Td# commands regardless of this setting
// Set to _OFF and OnStep will allow Syncs to change pier side for GEM mounts (on/off), default=_ON
// Set to _ON and OnStep will remember the last auto meridian flip setting (on/off), default=_OFF
// Set to _ON and OnStep will remember the last meridian flip pause at home setting (on/off), default=_OFF
// ADJUST THE FOLLOWING TO MATCH YOUR MOUNT --------------------------------------------------------------------------------
#define REMEMBER_MAX_RATE_OFF       // set to _ON and OnStep will remember rates set in the ASCOM driver, Android App, etc. default=_OFF
#define MaxRate                   44 // microseconds per microstep default setting for gotos, can be adjusted for two times lower or higher at run-time
                                     // minimum* (fastest goto) is around 32 (Mega2560,) 16 (Teensy3.2,) 12 (Teensy3.5,) 4 (Teensy3.6,) default=96 higher is ok
                                     // * = minimum can be lower, when both AXIS1/AXIS2_MICROSTEPS are used the compiler will warn you if it's too low
#define DegreesForAcceleration   5.0 // approximate number of degrees for full acceleration or deceleration: higher values=longer acceleration/deceleration
                                     // Default=5.0, too low (about <1) can cause gotos to never end if micro-step mode switching is enabled.
#define DegreesForRapidStop      1.0 // approximate number of degrees required to stop when requested or if limit is exceeded during a slew: higher values=longer deceleration
                                     // Default=1.0, too low (about <1) can cause gotos to never end if micro-step mode switching is enabled.
#define BacklashTakeupRate        25 // backlash takeup rate (in multipules of the sidereal rate): too fast and your motors will stall,
                                     // too slow and the mount will be sluggish while it moves through the backlash
                                     // for the most part this doesn't need to be changed, but adjust when needed.  Default=25
                                     // Axis1 is for RA/Az
#define StepsPerDegreeAxis1  7680.0      // calculated as    :  stepper_steps * micro_steps * gear_reduction1 * (gear_reduction2/360)
                                     // G11              :  400           * 32          * 1               *  360/360              = 12800
                                     // Axis2 is for Dec/Alt
#define StepsPerDegreeAxis2  7680.0     // calculated as    :  stepper_steps * micro_steps * gear_reduction1 * (gear_reduction2/360)
                                     // G11              :  400           * 32          * 1               *  360/360              = 12800
                                     // the EM10b has two spur gears that drive the RA/Dec worms, they give an additional 1.25:1 reduction
                                     // in addition to the 18:1 gear heads on the steppers for a 22.5:1 final ratio before the worm/wheels at 144:1
                                     // PEC, number of steps for a complete worm rotation (in RA), (StepsPerDegreeAxis1*360)/gear_reduction2.  Ignored on Alt/Azm mounts.
#define StepsPerWormRotationAxis1 19200L
                                     // G11              : (12800*360)/360 = 12800
#define PECBufferSize           600  // PEC, buffer size, max should be no more than 3384, your required buffer size >= StepsPerAxis1WormRotation/(StepsPerDegeeAxis1/240)
                                     // for the most part this doesn't need to be changed, but adjust when needed.  824 seconds is the default.  Ignored on Alt/Azm mounts.
#define MinutesPastMeridianE      60 // for goto's, how far past the meridian to allow before we do a flip (if on the East side of the pier) - one hour of RA is the default = 60.  Sometimes used for Fork mounts in Align mode.  Ignored on Alt/Azm mounts.
#define MinutesPastMeridianW      60 // as above, if on the West side of the pier.  If left alone, the mount will stop tracking when it hits the this limit.  Sometimes used for Fork mounts in Align mode.  Ignored on Alt/Azm mounts.
                                     // The above two lines can be removed and settings in EEPROM will be used instead, be sure to set the Meridian limits in control software if you do this!  
                                     // If you don't remove these lines Meridian limits will return to these defaults on power up.
#define UnderPoleLimit            12 // maximum allowed hour angle (+/-) under the celestial pole.  Default=12.  Ignored on Alt/Azm mounts.
                                     // If left alone, the mount will stop tracking when it hits this limit.  Valid range is 10 to 12 hours.
#define MinDec                   -91 // minimum allowed declination, default = -91 (off)  Ignored on Alt/Azm mounts.
#define MaxDec                   +91 // maximum allowed declination, default =  91 (off)  Ignored on Alt/Azm mounts.
                                     // For example, a value of +80 would stop gotos/tracking near the north celestial pole.
                                     // For a Northern Hemisphere user, this would stop tracking when the mount is in the polar home position but
                                     // that can be easily worked around by doing an alignment once and saving a park position (assuming a 
                                     // fork/yolk mount with meridian flips turned off by setting the minutesPastMeridian values to cover the whole sky)
#define MaxAzm                   180 // Alt/Az mounts only. +/- maximum allowed Azimuth, default =  180.  Allowed range is 180 to 360
                                     // Axis3 is optional and for a rotator/de-rotator
// AXIS1/2 STEPPER DRIVER CONTROL ------------------------------------------------------------------------------------------
// Reverse the direction of movement.  Adjust as needed or reverse your wiring so things move in the right direction
#define AXIS1_REVERSE_ON           // RA/Azm axis
#define AXIS2_REVERSE_OFF           // Dec/Alt axis
// Optional stepper driver Enable support, just wire Enable to Pins 25 (Axis1) and 30 (Axis2) and OnStep will pull these HIGH (Teensy3.x Pins 16,21)
// by default to disable stepper drivers on startup and when Parked.  An Align, Sync, or UnPark will enable the drivers.  Adjust below if you need these pulled LOW to disable the drivers.
// For equatorial mounts, _ON powers down the Declination axis when it's not being used to help lower power use.  During low rate guiding (<=1x) the axis stays enabled
// for 10 minutes after any guide on either axis.  Otherwise, the Dec axis is disabled (powered off) 10 seconds after movement stops.
// Basic stepper driver mode setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
// If used, this requires connections M0, M1, and M2 on Pins 22,23,24 for Axis1 (RA/Azm) (Teensy3.x Pins 13,14,15.)  M0, M1, M2 are on Pins 27,28,29 for Axis2 (Dec/Alt) (Teensy3.x Pins 18,19,20.)
// Stepper driver models are as follows: (for example AXIS1_DRIVER_MODEL DRV8825,) A4988, LV8729, RAPS128, TMC2208, TMC2130 (spreadCycle,) 
// TMC2130_QUIET (stealthChop tracking,) TMC2130_VQUIET (full stealthChop mode,) add _LOWPWR for 50% power during tracking (for example: TMC2130_QUIET_LOWPWR)
#define AXIS1_DRIVER_MODEL DRV8825   // Axis1 (RA/Azm):  Default _OFF, Stepper driver model (see above)
#define AXIS1_MICROSTEPS 32          // Axis1 (RA/Azm):  Default _OFF, Microstep mode when the scope is doing sidereal tracking (for example: AXIS1_MICROSTEPS 32)
#define AXIS1_MICROSTEPS_GOTO_2      // Axis1 (RA/Azm):  Default _OFF, Optional microstep mode used during gotos (for example: AXIS1_MICROSTEPS_GOTO 2)
#define AXIS2_DRIVER_MODEL DRV8825   // Axis2 (Dec/Alt): Default _OFF, Stepper driver model (see above)
#define AXIS2_MICROSTEPS 32          // Axis2 (Dec/Alt): Default _OFF, Microstep mode when the scope is doing sidereal tracking
#define AXIS2_MICROSTEPS_GOTO_2      // Axis2 (Dec/Alt): Default _OFF, Optional microstep mode used during gotos
// Note: you can replace this section with the contents of "AdvancedStepperSetup.txt" . . . . . . . . . . . . . . . . . . . 
// Stepper driver Fault detection
// just wire driver Fault signal to Pins 26 (Axis1) and 31 (Axis2), default=_OFF (Teensy3.x Pins 17,22) other settings are LOW and HIGH (if available applies internal pullup if LOW and pulldown if HIGH.)
// ------------------------------------------------------------------------------------------------------------------------
// FOCUSER ROTATOR OR ALT/AZ DE-ROTATION ----------------------------------------------------------------------------------
// A9,A8 = Step,Dir (Teensy3.x 30,33 choose either this option or the second focuser, not both)
#define ROTATOR_OFF                  // enable or disable rotator feature (for any mount type,) default=_OFF (de-rotator is available only for MOUNT_TYPE_ALTAZM.)
#define MaxRateAxis3              10 // this is the minimum number of milli-seconds between micro-steps, default=8
#define StepsPerDegreeAxis3     64.0 // calculated as    :  stepper_steps * micro_steps * gear_reduction1 * (gear_reduction2/360)
                                     // Rotator          :  24            * 8           * 20              *  6/360                = 64
                                     // For de-rotation of Alt/Az mounts a quick estimate of the required resolution (in StepsPerDegree)
                                     // would be an estimate of the circumference of the useful imaging circle in (pixels * 2)/360
#define MinAxis3                -180 // minimum allowed Axis3 rotator, default = -180
#define MaxAxis3                 180 // maximum allowed Axis3 rotator, default =  180
#define AXIS3_REVERSE_OFF            // reverse the direction of Axis3 rotator movement
// FOCUSER1 ---------------------------------------------------------------------------------------------------------------
// A11,A10 = Step,Dir (Teensy3.2 pins 31,32) (Teensy3.5/3.6 pins 34,35)
#define FOCUSER1_OFF                 // enable or disable focuser feature, default=_OFF
#define MaxRateAxis4              10 // this is the minimum number of milli-seconds between micro-steps, default=8
#define StepsPerMicrometerAxis4  0.5 // figure this out by testing or other means
#define MinAxis4               -25.0 // minimum allowed Axis4 position in millimeters, default = -25.0
#define MaxAxis4                25.0 // maximum allowed Axis4 position in millimeters, default =  25.0
#define AXIS4_REVERSE_OFF            // reverse the direction of Axis4 focuser movement
// FOCUSER2 ---------------------------------------------------------------------------------------------------------------
// A13,A12 = Step,Dir (Teensy3.x pins 30,33 choose either this option or the rotator, not both) 
#define FOCUSER2_OFF                 // enable or disable focuser feature, default=_OFF
#define MaxRateAxis5              10 // this is the minimum number of milli-seconds between micro-steps, default=8
#define StepsPerMicrometerAxis5  0.5 // figure this out by testing or other means
#define MinAxis5               -25.0 // minimum allowed Axis5 position in millimeters, default = -25.0
#define MaxAxis5                25.0 // maximum allowed Axis5 position in millimeters, default =  25.0
#define AXIS5_REVERSE_OFF            // reverse the direction of Axis4 focuser movement
// -------------------------------------------------------------------------------------------------------------------------
#define FileVersionConfig 2
#include "src/pinmaps/Pins.Classic.h"

Podem me ajudar ?  


Fábio Rodrigues

Re: I know this is geared to OnStep, but looking for fork mount plans

George Cushing

Look at pretty much any Dobson and you have a basic Alt/Az fork mount. Add EQ wedge and you have an EQ mount.. I've seen 'em built with everything from plywood to channel iron. Look at the non-driven wheel spindle from any auto and you have the basis of the RA axle.

Re: Automatically flipping when reaching the ASCOM Meridian W. Limit Value


Yes i have the same problem with Ekos Henk (Dutch like me?).
Could you test the HA counter in Ekos?
It updates the time left when the target is synced but the counter stays there without counting down like it is supposed to.

Re: Can i lower the goto speed to 0.1x


from the experiments i just did if you press slowest it actually goes faster than the  default if you set the select desired to 0.05.
you can  change acceleration distance to larger if you want, i don't know the maximum is , you would normally do that if you have a large OTA with a lot of inertia and fast slewing.

Have you looked at the resistors on the back of the driver and what did you set Vref to on the little adjuster on the top?
what voltage do you us?
have you any numbers for the motors and gearboxes printed on them.?
You could also try setting the AXISx_DRIVER_MICROSTEPS_GOTO 2 the same as the normal one so at least it is one less variable.
What effect do higher micro-stepping values have?
also check for solder problems, the micro stepping  is controlled from the processor pins so a bad joint can produce the wrong stepping.

can you check that your tracking rate is correct. when enabled only one  motor should rotate at the worm should do 1 rotation in 5 mins 37.9seconds .

looking at the video of the right one rotating and the grub screw it would appear to be taking roughly 16 seconds to do one turn. as your worm is 225teeth that is 1.6 degrees per tooth  so that would actually be about  0.1 degrees per second. Can you time them accurately or record a full revolution.

As there are knobs on the end can they be rotated by hand if there is no power connected and the motors unplugged?
what do the knobs feel like if the omotor is turninbgd doing a tracking and also when they are rotating like in the video?

MKS GEN-L V2.1 TMC5160



I'm building my goto controller based MKS GEN-L V2.1 with TMC5160 micro stepper, and i read on wiki that "Just configure the shunts under the stepper socket for SPI mode and plug them in" Despite numerous readings of documentation i'm not able to find those and how to set them. 
Thanks in advance for your help

Re: Can i lower the goto speed to 0.1x


I recorded two video clips, same setting.
1st is Goto button being pressed
2nd is during motor stalling and Abort button is pressed(waited some seconds).

Re: Can i lower the goto speed to 0.1x


Hi Kevin,

I set the SLEW_RATE_BASE_DESIRED to 0.001 and set Goto speed to slowest in Android App. When i select an object and press Goto button the motor still driving at higher than expected speed and stalling there. When i press the Abort button, seconds later the two motor can rotate at normal. Is this problem caused by the SLEW_ACCELERATION_DIST? Can i change the 5.0 value to less or more to make the motor start at slowerst speed? Thanks again.

On Sun, Jan 23, 2022 at 02:54 AM, kevin wrote:

To get over inertia etc it accelerates slowly so you don't get to this rate until SLEW_ACCELERATION_DIST   5.0. degrees.

Re: Can i lower the goto speed to 0.1x


Forgot to say the slider when default is 0.05 goes between 0.1 and 0.03 deg however again this is a rounding/display issues as the time indicates that it would be 4 times the 0.1 time so actually 0.025 degrees as expected.

just tried it with 0.1 deg/sec and faster /fastest works as expected ( 0.2,0.15) but slower and slowest both still only give Ascom 0.07 degrees although reporting 0.1 on the display same as default.  the Ascom slider goes from 0.2 down to 0.05 deg
with 0.2 degrees you get slower Ascom  0.13 ( actual 0.14, display 0.1)  and slowest   0.1, the slider is then 0.4 to 0.1 degrees.

This may all seem confusing but it is fairly standard when you do maths with limited accuracy and very small numbers. Basically if you have 0.2 degrees/sec or higher you will get 5 speeds from the android app. The SHC may work differently and if you have Ascom working you can go down to 0.25 degrees/sec. I haven't tried slower  :-)

Re: Can i lower the goto speed to 0.1x


Normal is what you set in the config.h file, or the config generator if you used that. Currently you have 0.2 in the one you attached. #define SLEW_RATE_BASE_DESIRED  0.2 Change it to 0.05 and you will then you should have 0.025 ( 0.5X) to 0.1 ( 2X) to try. ( see issue below)
To get over inertia etc it accelerates slowly so you don't get to this rate until SLEW_ACCELERATION_DIST   5.0. degrees.
 I have just reloaded my controller with 0.05 but don't have a mount connected. I haven't used the SHC, but for testing I am using the Android app. I also have the Onstep Ascom driver loaded on my computer and i can see the properties in that.
In the app i get the slew rates in multiples of the tracking rates when in the tracking window as it is for guiding and only going small distances.
I think it just uses the SLEW_RATE_BASE_DESIRED automatically when it does a GOTO as fast as it can. in the android app I have an option to change the GOTO rate but I can't get the GOTO speed to display anything other than 0.1 deg./sec even when by pushing the  slowest button.
This may actually only be a rounding issue caused by  displaying to .1 degree steps.   because if i change the app speed the reported speed in the Ascom telescope chooser Onstep driver properties give 0.05 for default  faster gives 0.08 and fastest gives 0.1. these would all "round up" to 0.1 for display.
There does seems to be a problem somewhere though because slower and slowest both give 0.07?
I can actually use the slider in the Ascom properties to go below 0.5 and then my app displays 0.0 degrees, as in the botom right corner of this.

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