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:
https://learn.watterott.com/silentstepstick/protector/

Bob,
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.  

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.

On Tue, May 10, 2022 at 10:19 PM, eugenecisneros wrote:

S5160

Eugene,
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. 

Bob

FYI, Bigtreetech website

TMC5160

Back in stock on 26th,May

You can pre-order, $16.84

Agreed.  

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:

Looks like you are buying into another obsolete product.

Bob

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.
https://onstep.groups.io/g/main/files/Utilities%20for%20STM32

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.

-Mike

A good summary Otto.

I would add that versions of OnStep prior to the current release-4.24 (that is, anything earlier than version 4.24q) may have a bug where the variable guide rate guide commands (and spiral search) trip up pulse guiding.  That was patched back in March.

If you don't want to update to the latest, the solution is to be sure you set the guide rate (perhaps 0.5x) just before guiding starts.

This could really be incorrectly set backlash too, the above is just a possibility.

Amazon.com (in US) has them for $27 with soldered headers.  I also saw them on DigiKey.

Niki,

I use an EQ5 as well with an ASI120 (though on a 50mm SVBony guidescope).  I will go through my workflow for guiding:

- Polar drift align in PHD2 (be sure tracking is ON when doing this)
- 3 Star align in OnStep
- Run PHD2 and point the scope or camera to an area of the sky at +/- 20 deg in declination (this is what PHD2 suggests)
- Move the scope to the desired target and begin guiding, letting PHD2 automatically detect the guide star AND the exposure

A few things for you to check based on your problem
1) Did you set the correct guidescope focal length and camera pixel size in PHD2?
2) You mention this works well on a Skywatcher mount...does your EQ5 have significant backlash in either DEC or RA?
3) Are you doing guiding via WiFi or hard-wired from your computer to the OnStep board?

According to the WIKI, the pulse-guide command is always 0.25x, 0.5x, or 1.0x and never higher.

1. With this separate pulse-guide rate any rate set at 0.25x, 0.5x, or 1x applies to both the normal guide rate and the pulse-guide rate.  Any rate set above 1x is applied to the normal guide rate only and the pulse-guide rate will remain at the last setting (0.25x, 0.5x, or 1x.)

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 57.xxx (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.

I am just thinking about this:

If the EEPROM on the DS3231 is not working properly, will this result in the behaviour? How can I test the EEPROM?


Frank

Am 14.05.2022 um 10:31 schrieb Merowinger:

Hi

my name is Stefan. I'm newbie in terms of telescopes and just bought a Skywatcher Dobson 10" 250p.
I came across this awesome site full of great ideas and switched my former Intention to build a cnc machine, to motorizing my Dobson.

I do have most of the parts shown at this wiki entry, which does supply a lot of information, but unfortunately not detailed enough for me.

 I'm not the best electrician (although I try to get better :)), so I do have some missing knowledge on wiring up the components.

I own this kit:

• 3 Nema 17 1.8 200 steps
• 4 DRV8825
• Cncv3 shield
• 3 Endstops

Additionally

• D1 R32
• D1 mini
• DS3132RTC
• GT-U7 GPS
• BME/BMP280
• Active Buzzer 5v
• 3d printer
• soldering station
• elect. accessories (capacitors, etc.)

Of course I know that with this kind of components there is not much to expect in terms of accuracy, but I would be glad to use it as guiding help for visual scoping
and to learn more about the night sky, telescopes and the ecosystem around it.

My scope with 3d printed gears and endstoppers: 

Gear reduction on azimuth 44:1 and altitude 22:1



I read the wiki up and down and found a lot, so that I was able to tune the stepper drivers to 0.75A.
Configuring OnStep and uploading it to the R32 worked and I was able to steer both steppers manually with the Android app.

Goto did not work for me, as the dobson just turned around in circles after setting it up aligning as described here.

So there a few questions, I do not find an answer for and would be very pleased if someone could shed some light into it.

1. DRV8825 the 1.5A (0.75A) are without heatsink - I read somewhere that with heatsink 2A (1A) max is possible, true and does this improve something?
2. Is OnStepX possible to run the SWS on the same R32 or do I always have to use the D1 mini additionally
3. How would I connect the D1 mini to use the SWS for accessing OnStep?
4. I did not get the endstoppers to work, when configuring the as LimitSense Low - I guess also the wiring was wrong...
5. How do I wire up the additional components? It was not possible for me to get them to work, I think the reason is setting the correct pins.

Here are images of my components as well as my current config for OnStep:



Any help would be appreciated, thank you!

Best regards

Stefan

Hi! 

I am calibrating wherever i am looking at. So most of the time near the object i plan to photograph. With my other two mounts (Skywatcher) this always worked flawless. I AM northern hemisphere, yes. I know that the box size can be changed in size, but even the largest wood be far to small for the initial move. 

I managed to capture a video of the LARGE move the first pulse does, so you can see.