Re: Guiding Problems with PHD2 and OnStep


Hello Mr Dutton!

I am not used to programming the system, since i did not build it on my own. 
I have to check what version i run and will see if this triggers my problem.
I do think that the backlash correction you mentioned could be the main problem, becaus i DO have big backlash in dec and managed to measure that and program a correction in PHD. Maybe this correction is still active and causes problems.

I DO check guide rate all the time by now...

Re: Guiding Problems with PHD2 and OnStep


Hey! Time to answer now finally... 

Wanted to give all your kind suggestions a try tonight but clouds...

I align with the new Alignment routine of N.I.N.A. now, because it is way faster then the drift alingnment of PHD2, just for info
I do NOT make a 3 Star alignmet, because i platesolve so this is imho useless for me.
Guidescope indeed was entered wrong some time ago but ist is right now.
I DO have a VEEERY Big Backlash in DEC that i was NOT able to get away atm.
I guide via the Stick PC thats mounted right on my mount so, NO, i do not have a problem with delay over WIFI. The Control Computer goes with the scope...

Re: I can´t flash the wemos esp32 #EQ5 #error #wemos #esp32


Oh sorry, I will remember it.

Thank you so much, now it works. I'm so happy 😊

Re: Help for wiring up CNCv3 - DRV8825 -R32 - D1 #esp32 #wemos #250p #arduino #d1

Chris Whitener

Try without limits switches set.  and without home.  Sometimes these take a bit of understanding.
The SWS is separate.  it needs to be connected to a serial port.

Re: Help for wiring up CNCv3 - DRV8825 -R32 - D1 #esp32 #wemos #250p #arduino #d1

Fernando Nino Sr

Check out Oddvar Naess mod on his EQ5 mount, he has a wiring diagram for some of it using the same items you have. Also download the PDF file, much more information.

Re: I can´t flash the wemos esp32 #EQ5 #error #wemos #esp32

Dave Schwartz

Its very hard to make out the text from an image - in future, use the 'Copy error messages' button above the output area to paste the text directly in your email.

Your error messages say something about 'Tone'. I don't use the ESP32 controller but what I remember from previous discussions is that the maintainers of the ESP32 board manager have implemented their own 'Tone' method which conflicts with the one Howard has had for a very long time in OnStep. You are probably using the latest version of the board manager (2.0.2 or 2.0.3). Reinstall version 2.0.0 - it doesn't have this conflict (of a few other introduced problems).

On 2022-05-15 6:14 a.m., manadhion via wrote:
I would like to build a goto for my EQ5.

I buyed a Wemos ESP32 Dev Module and would like to flash this with the OneStep file and my config.h

Everytime i try to compilate this in Arduino IDE i get a exit status failure (See the pic) and i don´t know what is wrong.
Can everybody help me?

Thank you

I can´t flash the wemos esp32 #EQ5 #error #wemos #esp32


I would like to build a goto for my EQ5.

I buyed a Wemos ESP32 Dev Module and would like to flash this with the OneStep file and my config.h

Everytime i try to compilate this in Arduino IDE i get a exit status failure (See the pic) and i don´t know what is wrong. 
Can everybody help me?

Thank you

Re: Setting the tracking rate


Thanx Mike, I will check this out :-)

Am 14.05.2022 um 18:38 schrieb Mike Ahner:

On Sat, May 14, 2022 at 07:31 AM, Merowinger wrote:
If the EEPROM on the DS3231 is not working properly, will this result in the behaviour? How can I test the EEPROM?
Because the STM32F103/303 micros do not have onboard EEPROM, if the DS3231 isn't working, OnStep won't boot.

There are some test utilities in the Files section under STM32, there is one specifically for testing the EEPROM.

With the Blue Pill, normally you will not need to change the master clock, the Blue Pill is fairly accurate. But enable PPS in the Config.h file and OnStep will correct the clock with the temperature-compensated RTC of the DS3231.


Re: Setting the tracking rate


Thanx Drew for the answer, I activated PPS and I will continue setting up my system :-)

Next thing I learned is that the RA-motor is running wrong direction :-) I had to configure to invers. The DE-motor seems to be ok :-) (I did not understand in the moment, why only one of the motors must be inverted, both are wired identically, but ok, I will see if guiding works.)

Am 14.05.2022 um 15:55 schrieb Drew 🔭📷🚴 ♂:

On Sat, May 14, 2022 at 04:31 AM, Merowinger wrote:

I found the buttons to adjust the tracking rate, I tested it, but rate did not change, the rate is always 60.164 Hz in sidereal.
There is a common misperception as to what the buttons do and what the tracking rate is showing. The tracking rate is reporting the requested tracking rate. The heavens move at 60.164 Hz, change it to Lunar, and it will report the (I don't remember the exact number) rate requested to track the moon.

The tracking rate buttons adjust the master clock to correct for errors in the board clock. Some MCU's have inaccurate clocks, some do not.  The STM32 is not bad (ASIK) and should not require adjustment. PPS will improve the accuracy to as good as you can get.

If you are experiencing drift, look at the stepper math first. A one-step error can generate a huge amount of drift.

Re: Guiding Problems with PHD2 and OnStep

Derek Regan

It also shows you selecting the star, let PhD choose... Can't really see on the video but did it lose the star on the first guide pulse? As the first calibration step on my setup is fairly small, sure the guide pulse increase as the steps do..

Re: Guiding Problems with PHD2 and OnStep

Derek Regan

So you're using a ST4 cable to the mount?  
The video shows a box far too small for the guide pulse, not so sure that you can decrease the pulse but you can increase the box in size... If it works on your other setups then something is different,either calibration step size, guide pulse size, something like that..don't think it has anything to do with Onstep, more PhD setup

Re: My Dobson project

Tomas de Mora

Hello everyone.
A few months have passed since the beginning of this post, the project is already finished and I wanted to finish it with a summary of the material used in case it was of interest to someone. I expose it here since this post is linked to the wiki. I didn't want to go into too many details as it would be very long, many things to study and many problems to solve, but I had a good time.
When I started I had no knowledge of pulleys, belts, stepper motors, torques, gears and many others, also of astronomy although I have been in that for a few years now.
I don't go into technical questions of connections or configurations, everything is well covered by the wiki or by the messages in this forum.
You will always find someone to help you, like me, but expose it clearly and with as much information as possible about your problem.
A video of the mount running.

For its construction I have used 15mm plywood, except for the Declination platform which is 10mm, the round base is made of 19mm MDF, heavier, trying to achieve greater stability.

For the assembly I have used M5 30mm screws with bushings for formwork in wood, for the exposed areas the same round-headed screws, more attractive. The shafts are through M8 screws, the holes have bearing bushes. For the rest of the material M4 screws of different lengths.


After trying different solutions I decided to use a 35cm diameter metal sliding platform (Lazy Susan), by far the best solution.

In the construction it is necessary to pay great attention and precision in the drilling of both axes, the two axes must be perfectly perpendicular to the optical axis of the telescope.


I made the secondary pulleys and the motor supports using 3DStudio for the design and a 3D printer (Prusa MK2) for its manufacture, I leave you the link to Thingiverse.

The pulleys could not have been larger due to the limitations of the printer and due to warping problems.
When I ordered the engines

I did not observe that this model comes with a Key-Way on the shaft, that meant having to rethink the selection of pulleys and belts since I did not find GT2-type key-way pulleys in any supplier, I only found a solution with 3mm pitch pulleys (HTD3M) of 25 teeth the smallest. I have had to admit a lower resolution for this reason.

I also had problems with the HTD3M straps, finding ones with the required length and not very wide was not easy, I finally found ones with a width of 10mm. In the end I had to place the motors based on the length of the belts that I found.



I chose the solution with the Wemos R32 with CNC V3, using LV8729 drivers. I made the pcb for the rest of the components using EasyEda for the design and then a CNC machine for its manufacture, there are three pcb`s, one for two step-dawn at 5v and 3.3v, another for the connections with the motors and a third for the ESP8276, the clock and the rest of the connections to terminal ST4 and BME280.


In this case I did not find any problem, both in the initial tests and later with everything assembled and welded, it always worked well. Without trying the ST4 connection for guidance which I will probably never use, this is not made for that. I did manage to set up a MagicSee though I don't think I'll use it much.


In the final tests I still haven't got a precise GoTo but I'm very close, my problem is that I don't have time or continuity to do tests.

I have the SLEW_RATE_BASE_DESIRED in 3, a bit slow, it is seen in the video, for me it is enough, but I think it can be improved.

In conclusion I could say several things:

*** The motors, I think, are excessive for what is required, just perhaps because of the 100:1 reduction that in my case and I suppose that in any other Dobson transformation it is fundamental. Today I would have chosen these


Their only difference is that they have a strange reduction of 99.5:1 that should be taken into account, in their favor, they are cheaper, they are delivered without a Key-way, which allows the use of GT2 pulleys and belts, facilitating their construction and reducing the final cost and deliver more torque at higher speeds.


When I started the project I had neither a telescope nor a mount and I decided to make the mount myself and buy the telescope, I don't know if I would do it today, I think that for those who already have a Dobson mount with a Telescope for very little money it can be motorized, but If you have to buy and do everything, I think it's better to buy a complete new or second-hand piece of equipment. In Spain, an 8” motorized retractable Skywatcher with Goto is worth less than €1,100. I don't know how much I have saved since I have spent much more than necessary on trial and error and oversized orders, but I don't think more than €200-250. I don't know if it's worth it. Although the fun and learning are not quantified.


But I intend to put OnStep on my AVX.!!!!

OnStep is a great project, once again my congratulations to Howard and everyone who collaborates on this excellent solution.

I'm sorry if there is any lack or inconsistency in my English, it's collaborative google<-> person.
Greetings and good starry skies



Re: TMC5160 substitute?

Robert Benward

Thank you!  That makes perfect sense now.  Looking at them again, yes they look  like protection diodes and not MOSFETs.   So, you don't need the bottom board for our purposes.

I wonder why Trinamic obsoleted them (the TMC5161).  

I also realized the basic TMC5160 is a 60V chip, it must be the MOSFETs that limit them to 35V.  The QHV5160 must be using higher voltage MOSFETS


Re: Help for wiring up CNCv3 - DRV8825 -R32 - D1 #esp32 #wemos #250p #arduino #d1


Hi George,
thanks for your offer. Shipping to Germany is no problem?

I want also to add a motor focuser at a later point, is that possible given that I see only 2 stepper driver slots on the design?

Re: TMC5160 substitute?

Howard Dutton

On Fri, May 13, 2022 at 05:33 PM, Robert Benward wrote:
Those 5161 are strange beasts.  The external MOSFETS are on a board below and I suspect the chip output is being used to driver the gates of the mosfets, but since the upper board is available alone, I don't know how they break the pin-to-socket-to-pin connection to route the outputs to the gate inputs.  The Fysetc wiki shows the upper boards as available separately.  The upper board alone can handle 3.5A.   I wonder where the power board comes from
AFAIK the MOSFETs of TMC5161's are on-die where the TMC5160 has the MOSFETs off-die and that is the only difference.

Thinking the second board they plug into is one of these basically:

Re: TMC5160 substitute?


Re the S5160s that I ordered, the vendor says send them back if they are not compatible.

Thanks for the info re TMC5160s back in stock on 26th May.  I pre-ordered 4 pieces and using the discount code it came to $60.63 with free shipping.  So, $15.16 ea.  

Re: Guiding Problems with PHD2 and OnStep

Pablo Lewin

Do you have the PEC correction on? if so TURN IT OFF! I had a similar problem with my CGE Pro and I couldn't understand why the stars/mount would jump around..then I turned the PEC off and voila!..try it...even if it's not the problem, it's one less variable to deal with till you find what's wrong..

Pablo Lewin
The Maury Lewin Astronomical Observatory
Glendora CA. USA.

Re: TMC5160 substitute?

Robert Benward

On Tue, May 10, 2022 at 10:19 PM, eugenecisneros wrote:
I just looked at what you are buying, they look identical to what I purchased, yet they are rated at only 35V.  Note my comment about board overhang in my previous post.  This will apply to the drivers you just bought.  This will be OK on the STM32 blue pill, it might fit the minis, but I doubt it, and it will not fit any of the Max series without  "adjustments" I described before. 


Re: TMC5160 substitute?

Robert Benward

FYI, Bigtreetech website


Back in stock on 26th,May

You can pre-order, $16.84

Re: TMC5160 substitute?

Robert Benward


My point is the "chip" alone can drive 3.5A, and the board below has the Mosfets.  The pins seem to be pass through, from pin to header and to pin again, so I am curious as to how the pins are separated or "broken out" when you stack them.  The headers and pins are directly over each other so I would like to know how they are doing it.   

Also, I can't seem to find any technical info on the driver board, no current specs, nothing.  So, what is it you are buying?  They are also not longer available on AliExpress.
Also, from Trinamic's website:


This product is no longer available
Looks like you are buying into another obsolete product.


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