Re: Simulate Alt/Azm movements in Equatorial mounts?

Patrizio Boschi <patrizio.boschi@...>

Hi, thank you all for the replies.

I understand the "reverse wedge" or align RA to zenith thing, but that practically disrupts the possibility to use the EQ mount for other "regular" things during the same session. I would like to keep the mount correctly aligned to celestial pole (because it's an EQ mount) AND be able to decide to move the scope using the hand controller with either RA/DEC or Alt/Azm logic - I mean, to decide it on the fly with a flip of an option. In fact you can already do that on some stellarium programs.

The controller (OnStep for us, but also the commercial ones) should understand that if you want to move "up" it just needs to move the two axes in some manner, and even to do a flip if you are reaching physical limits. It's already doing it whenever you do a GoTo. It just seems to me that the correct LX200 commands are missing, as we have:
  • :Mn# Move north
  • :Ms# Move south
  • :Me# Move east
  • :Mw# Move west
  • :Mp# Move in spiral manner
  • :MA# Move to Az/Alt coordinates
  • etc
But we are missing:
  • :Mu# Move up
  • :Md# Move down
  • :Ml# Move left
  • :Mr# Move right

I've checked OnStep code, and I think the commands could be added and I would like to have the time to try to implement them - I'm however still missing the math step to transform an "Up" command to 2 coordinated guide commands on RA/DEC axes (considering the eventual limiting speeds etc). In fact I see that an even more complex thing was implemented for Spiral Search, so I don't think it isn't feasible (but again I'm missing some of the math).

It's not a critic to any mount controller, I just don't understand why a similar basic function was never implemented by anyone in the world in any mount controller. It's the first thing people want to do when using a telescope - to move it reliably by hand around the human-undestandable reference points.

Kind regards,

Two focusers simultaneously via ASCOM driver

Lucas Socha


Is it possible to configure an ASCOM driver, so two focusers can be used at the same time - like for example in Maxim DL, where two ASCOM focusers can be connected? 

I tried connecting first by selecting Focuser 1 in ASCOM panel and second by selecting Focuser 2, but it apparently selects the same Focuser in all ASCOM driver instances.

If that is not possible, is there any other way to control both focusers at the same time in Windows OS?

Many thanks in advance,

Re: Sky Safari GOTO limits


I think I may found what is the problem here.

First of all, you need to check values set in SWS (advanced axis config) because they will took over. To me, it looks like values set by config.h are not applied after re-upload, but the values from SWS are instead. And pay attention that after changing these values in SWS manual restart is required.

And second, it looks to me that these values are not counted for 0 (wedge down) but from most east and most west position. I wanted to set the same limits like I have in EQMOD, but when I set -120 and +120 it effectively only goes 30 degrees east and west, which is equal to 2 hours RA (or 1 hour in clock dial). In order to make RA axis goes from 8-4h (as RA circle is imagined as a clock dial), so I needed to set limits to -210 and +210.

Default values of -180 and 180 would represent 9-3h. Your values -160 and 160 would be something like 10-2h.

Re: Sky Safari GOTO limits

Robert Benward

Yes. Both of those are set.  I am navigating the entire sky, except for that area under the pole.

Good idea.  I will see what alternate program I can download.

Re: Sky Safari GOTO limits


In SkySafari under Settings/Scope Setup do you have following settings:

Scope Type: Meade LX200 Classic
Mount Type: Equatorial GoTo (German)

Can you try other planetarium app, just to check if the problem is in the controller or in SkySafari?

Re: Hardcoded pulseguide limit?


If you are sure this is just to prevent switch stuck and not due to some hardware limitations (timer resolution, etc), I could increase this value because I don't use switches. I don't get it why exactly 16399ms... For normal scenario everything would be okay, for dithering more pixels on shorter fl camera lenses PG hits this limit.
It is unclear if the value of GUIDE_TIME_LIMIT is in terms of arc seconds or seconds of time and does it applies to PG length or manual guiding or both or none of them.

Re: Question about TMC2130 Stepper Drivers

Ken Hunter

Thanks Khalid...
Maybe that explanation should be included in the Wiki to reduce confusion?

Re: Hardcoded pulseguide limit?

Robert Benward

This is to prevent a stuck switch from driving the mount in circles.  It forces you to let off the switch and then re-apply.  It's a safety thing.  I am sure the Manual Guide command is the same thing, capped at 16 seconds.

#define GUIDE_TIME_LIMIT                0 //      0, No guide time limit. Or n. Where n=1..120 second time limit guard.       Adjust

Re: Stepping up to 24V

Robert Benward

Get a schematic or specifications to make sure you can plug in 24V.  I am using a MaxESP and they come with switching buck regulators.  They drop the voltage down to 5V and take 35V or more on the input.  There may not be any need to provide a separate supply to the Wemos. 

Also, you may wish to change the connector on your set up.  It's dangerous to use 24V on the standard 5.5x2.1mm plug and socket.  Too many astronomy things run on 12V max and use the same plug.  In the dark when you're fumbling around is not the time to find out you inserted the wrong plug into a 12V socket.


Re: Simulate Alt/Azm movements in Equatorial mounts?

Robert Benward

Rotate your RA axis to the vertical and you're all set.  Or get a Dob.  

Once I did the reverse. I had an iOptron cube, but the older alt/az only model.  I just told it I was at the North Pole, and then tilted the cube's azimuth axis to my latitude.  It worked well enough that I modified the hand controller to accept ST4 commands and I was able to take pictures with it.


Sky Safari GOTO limits

Robert Benward

Hi All,
I am in the process of integrating my Onstep with my Losmandy.  So far so good, with a 10:1 planetary &24V, I can achieve a decent 2deg/sec.  I also have it running "goto"s from Sky Safari on my iPad.  This is where I run into the problem.  For some reason I cannot "goto" any object that is below the altitude of the NCP.  It doesn't generate any errors, it just sits there and does nothing.  The target coordinates show up on the status page, but nothing else.  If I hit stop and then select another target, above the altitude of the NCP, it goes there no problem.

I am not sure which settings I need to adjust. 

All from the Smart Webserver;
From the config page:
Horizon and Overhead limits -10deg & +90deg

Under Advanced:
RA  limits -160 min pos & +160 max pos
DEC limits -90 min pos & +90 max pos

How do I read this?  Will this give me plus or minus 160 deg from "up" or my home position?  I think even this is too  much, I probably don't want my RA any lower than 110 from vertical (meridian limits are +/-15).
For the DEC, don't I need more than +90 if I go from the zenith and continue doing down, south of the NCP?

I then set the RA limits to +/-180 and uploaded.  It improved slightly, but I still cant get to anything below a horizontal line that intersects with the NCP.

I checked the wiki and maybe I missed it, but I couldn't find anything that would help.


Re: Simulate Alt/Azm movements in Equatorial mounts?


Another thought. Within the EQ mount restrictions i have no idea if the guiding port  controls would give you the  correct directions locally or if they set to move reasonable distances.?

Re: Simulate Alt/Azm movements in Equatorial mounts?


This may or may not be what you are trying to do.
I have just started  used Stellarium to control Onstep via the usb  and using lx200 mode or ascom.
I am new to all this so other progs may do it as well but Stellarium gives you a nice variable "virtual" view of the sky as a hemisphere. It  takes a little getting used to but with the horizon in ( you can even add a wraparound view of your own site). if onstep is set up correctly you can just click on a star and tell the telescope to go to it. if you zoom in an make it central ( space bar) then you can just click the next star over  and go to it. 
Stellerium doesn't give you a cursor pad but is you use Ascom you can then use "Ascom device hub" to give you cursor controls and i have even uses Sharpcap with ascom at the same time to get a second set of cursors. Sharpcap is connected to a couple of cameras as a wided view and a finder on the laptop and jus visual or another camera on the main scope.
I havn't found one yet but there is probably a Ascom hand controller , i may also have a go at using a USB numberpad just to get the keys i want mapped to the appropriate buttons.

Unfortunatly with an equatorial mount my understanding ( may be wrong , all new to me) is that at certain positons "just moving a bit left" actually needs the scope to move up to the celestial pole to flip sided of the pier and then come back down again. i still havn't got my mind clear on that bit .

It may be a silly idea, i was thinking as it for using my EQ for terestrial daytime  as well as stars,  but i was was considering   a "reverse wedge" . normally you add a wedge to an AZ to turn it into a EQ. should be able to  add a "wedge" so the polarscope points straight up? normal mounts wouldn't give the adjustment but  i have access to a EQ5 so it w"should " just be a couple of plates at the correct angle in between the tripod and the mount ( the OTA may hit the legs though at high angles ) .   maybe you can get fabricated a bit of metal to take the offset out (i.e 90 - latitude). Tracking wouldn't work with that though, but it may give you the effect you wan't, i am not sure.

Simulate Alt/Azm movements in Equatorial mounts?

Patrizio Boschi <patrizio.boschi@...>

Hi, maybe it's a stupid question, but is it possible to just be stupid and simulate the Alt/Azm movement in Equatorial mounts?

So when you press "N" on the SHC, instead of going "N" and move the DEC axis, it just goes "UP" (towards zenith) moving both axes using some math for coordinate transformation. "S" would go "DOWN" (towards nadir/horizon), "W"/"E" would go left and right on the sky's circle of latitude (or whatever it's called in english).

Does OnStep already include some math/logic functions to do that?

(...And why nobody wants it? Sometimes I just want to relax with visual observations, then I just want to watch "a bit on the left" in respect of the sky when I watch it with naked eyes, and it's very hard to decide what to do when the telescope inverts some directions, the finder inverts some directions, the SHC inverts some directions, then you change position around the telescope, then you change hand which holds the SHC, the RA/DEC axes rotate around invisible references, the brain is freezing, etc. In fact I can do that, but I also would be dead at the first turn if I had to apply the same logics when driving a vehicle.)

Re: Bluepill connecting

Khalid Baheyeldin

On Mon, Nov 22, 2021 at 06:37 PM, Peter Abbey wrote:
We have tried connecting both the SHC and the main Onstep directly by USB the same as we did for the Wifi module, but it won’t show up as mounted. We are getting a little red light on the USB connection on either devise but that’s all.
You cannot flash the STM32 module from the microUSB on the module itself.
You MUST flash it through the CP2102 module on the PCB.
And there must be power applied, and the Flash/Run switch has to be on Flash.

Read the Wiki page carefully again, and follow the instructions.

Re: Bluepill connecting

Peter Abbey

Help please,
I have completed the build of the Onstep bluebell kit and SHC, but am having trouble getting the firmware to load.

We managed to get the up load the firmware for the Wifi module. ( removed from main board and connected to computer, Macbook air running High Sierra)

We have tried connecting both the SHC and the main Onstep directly by USB the same as we did for the Wifi module, but it won’t show up as mounted. We are getting a little red light on the USB connection on either devise but that’s all.

I thought I had built everything correctly, but it’s not working.


Re: Another EQ6 build #neq6 #eq6


Since your PCB is SMD, hope you have some spares that you can sell, this looks very nice, great job!

Re: Question about TMC2130 Stepper Drivers

Khalid Baheyeldin

On Mon, Nov 22, 2021 at 02:48 PM, Ken Hunter wrote:
Is this saying that there are 2 different types of TMC2130s, TMC2130 and SSS TMC2130  and that they are treated differently?

SSS stands for SilentStepStick, which is TMC's nomenclature for their drivers.
They prefixed the previous term in the 3D community (StepStick) with 'Silent'.

StepStick is the module format for all drivers since Pololu introduced it.

While we are talking TMC2130 ...

The TMC2130 and TMC5160 are both SPI, which means boards that support
them have common wires connecting the drivers. They both support setting
the current in Config.h.

The differences is lower current maximum for the 2130 vs. 5160.
The former also has a potentiometer as an alternative way to set
the current.
It also heats up consideranly more than the 5160.

Question about TMC2130 Stepper Drivers

Ken Hunter

Extracted from the MaxESP3 config.h file...

// Stepper driver models (also see ~/OnStep/src/sd_drivers/Models.h for additional infrequently used models and more info.): 
// A4988, DRV8825, LV8729, S109, SSS TMC2209*, TMC2130* **, and TMC5160* ***
// * = add _QUIET (stealthChop tracking) for example "TMC2130_QUIET"
// ** = SSS TMC2130 if you choose to set stepper driver current (in mA) set Vref pot. 2.5V instead of by motor current as usual.
// *** = SSS TMC5160 you must set stepper driver current (in mA) w/ #define AXISn_TMC_IRUN (IHOLD, etc.)

Is this saying that there are 2 different types of TMC2130s, TMC2130 and SSS TMC2130  and that they are treated differently?

Re: Erratic motor rotation direction

Marco Lorenzi

Thanks Drew and Howard for pointing me to the right place and for the explanation, now I see it and it makes sense. My bad, spent time searching on the forum and didn't check properly all the details in the wiki :(
Thanks Drew also for the additional comments on the other settings! I am aware I still have to set the current limitation, I am setting this out now as I am learning a bit more on the setting details.
I am going to test your suggested settings right away :)

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