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Re: Project TinTac - a breadboard setup for testing OnStep code

James S. Albinson
 

Hello Khalid,
Yes, it is. The conversion to OnStep is ongoing in my mind, mostly, to replace the current commercial system that has problems.
I am working on TinTac, to test ideas, and on replacing some of the peculiar hardware.
Very much my thing. And it may never come to pass: there are many considerations.
Herewith an early commissioning image with the current system, which no longer works.
Regards, JAmes Albinson
M57 BRI filters, combined.


Re: Project TinTac - a breadboard setup for testing OnStep code

Khalid Baheyeldin
 

Wow ... 60cm Newtonian.
Would love to see images made through it ..

Must be the Thornton telescope at Keele Observatory then?

Also, I look forward to a writeup on how this was converted to OnStep, so it would feature on the showcase page.


Re: Project TinTac - a breadboard setup for testing OnStep code

James S. Albinson
 

Thank you Howard,
This is the sort of tip I appreciate as I am new to Arduino programming; my background is in Fortran.


Re: Default limits

Jamie Flinn
 

That is very cool especially if you don’t think in a sphere – visual of where the limit is is handy!!!...thanks

 

From: main@onstep.groups.io On Behalf Of Howard Dutton
Sent: Wednesday, July 29, 2020 1:00 PM
To: main@onstep.groups.io
Subject: Re: [onstep] Default limits

 

You can see what Axis1 min/max limits look like here (ignore the Tangent Arm Dec limits they don't apply here.)

https://onstep.groups.io/g/main/message/23434


Re: Connectors for frontal usage on the MINPCB1

George Cushing
 

Yes, Andre, I can get them to you. I also have a few MiniPCBv1 PCBs, 
George


Re: Project TinTac - a breadboard setup for testing OnStep code

James S. Albinson
 

Dear Khalid,
The mount was constructed 50 years ago by a heavy engineering co., and this is the 5th iteration of the drive system, reusing parts from the 3rd iteration.
The OTA is a steel frame of Brobdignagian proportions (500kg) with a 600mm f4.5 primary used at Newtonian.
A quick google on my name+observatory will reveal all, but as I replied to another poster, this is an individual project at present.
I will be considering TB6600 (Generic) driver blocks to run the stepper. Just that they are widely available and not too expensive.
OnStep should be perfectly good at running a radio telescope!!
Regards, James Albinson


Re: Default limits

Howard Dutton
 

You can see what Axis1 min/max limits look like here (ignore the Tangent Arm Dec limits they don't apply here.)

https://onstep.groups.io/g/main/message/23434


Re: Default limits

Jamie Flinn
 

Thanks – will play with those and see what happens (GULP!)

 

From: main@onstep.groups.io On Behalf Of Howard Dutton
Sent: Wednesday, July 29, 2020 12:05 PM
To: main@onstep.groups.io
Subject: Re: [onstep] Default limits

 

There are horizon and also Axis1 min/max limits in OnStep.

They stop tracking and prevent gotos.


Re: Project TinTac - a breadboard setup for testing OnStep code

Howard Dutton
 

On Wed, Jul 29, 2020 at 08:18 AM, <jsalbinson@...> wrote:
Maybe of interest: Bill Earl (https://learn.adafruit.com/multi-tasking-the-arduino-part-1/a-classy-solution)
There's plenty similar code in OnStep except I do the math correctly.

Don't use this form, it will fall down (after several days) due to overflow:

  • if((ledState == HIGH) && (currentMillis - previousMillis >= OnTime))

It should be:

if ((ledState == HIGH) && ((long)(currentMillis - previousMillis) >= OnTime))


Re: Boards and drivers required - help

Khalid Baheyeldin
 

As Markus said: if you get the MKS Gen-L, you don't need the RAMPS board, since the MKS Gen-L has everything that is on RAMPS built in (driver sockets for motors, ...etc.)

Regarding the power, you never run the driver or the motor at the max rated current.
Usually, you start at 40% of the motor (so 0.675A), and then test, tuning it up to say 70% of the 1.68A as a maximum.
You find where the sweet spot in that 40 to 70 range, that gives you fast slewing with no resonance/stalling.

You don't need the TMC5160 for those motors. The TMC2130 should be able to handle them, but make sure you have the heat sinks installed and monitor for excessive warming.


Re: OnStep Configuration Generator lives on ...

Khalid Baheyeldin
 

The OCG now has support for the TMC5160. The compiler will issue a warning that the default for IRUN is 600mA, with the name of the exact parameter. The user then has to go edit that parameter to whatever they want.


Re: Connectors for frontal usage on the MINPCB1

Khalid Baheyeldin
 

On Wed, Jul 29, 2020 at 12:11 PM, andre_moutinho wrote:
Does anyone have the RJs, USB and power connector components models for such assembly and where I could find them? 
The magic term is called: "vertical build".

Check the MiniPCB page, and scroll down to "Special notes for vertical build".


Building the PCBMAX with frontal panel connectors

andre_moutinho
 

The original G11 drivers use a frontal side RJ, power, etc  connectors and I would like to know if anyone here have builded the controller box using such connectors configuration.

Thanks
Andre


Connectors for frontal usage on the MINPCB1

andre_moutinho
 

Hi,

The MINPCB1 PCB for the EM10 has the connectors to be plugged on the board frontal side (not at the side such as 90 degree connectors).

Does anyone have the RJs, USB and power connector components models for such assembly and where I could find them? 

Thanks
Andre


Re: Default limits

Howard Dutton
 

There are horizon and also Axis1 min/max limits in OnStep.

They stop tracking and prevent gotos.


Re: Project TinTac - a breadboard setup for testing OnStep code

Howard Dutton
 
Edited

On Wed, Jul 29, 2020 at 07:36 AM, <jsalbinson@...> wrote:
Still digesting some of the earlier comments, but the tan(theta)/theta function worries me a bit as both tan(theta) and theta go to zero, while the ratio analytically goes to 1, I doubt the computer can cope with zero/zero - it usually falls over. Therefore I found a series expansion for tan(theta), divided it by theta to get a series = 1+ term in theta**2 + term in theta**4 + term in theta**6. USe of a decent spread sheet, but putting in the zero terms by hand, give the result I commented on earlier. I will have another look at the code to see what I am missing. More coffee...
Below is how I see it, at least for a TA drive with a "sliding pivoting arm" i.e. the screw is fixed (at both ends) relative to the axis and the arm travels along it.  I'm no expert on TA's but I also didn't find much design info. online so this is my best understanding.  I kept things simple by using unity for the radius and 100 tpi for the screw.

1. As shown with the arm perpendicular to the screw the ratio is exactly 628:1.
2. To reach a real axis angle of 45° you would need 1" of travel.  Since tan(45) = 1 this checks out (1 * 100 = 100 steps if working at 1 step per rotation of the screw.)
3. To reach a real axis angle of 63.4° you would need 2" of travel.  Since tan(63.4) = 2 this checks out (2 * 100 = 200 steps if working at 1 step per rotation of the screw.)
4. If the TA is at 150 steps and you want to know the axis angle atan(150/100) = 56.30° which in angular steps (as opposed to angular degrees) would be 56.30 * (628/360) = 98.21 steps.




Re: Project TinTac - a breadboard setup for testing OnStep code

Khalid Baheyeldin
 

James,

Looking at the motors (NEMA 34), I think these are the largest I've seen for OnStep over the past 3 years or so.

Can you share what the mount is, and what OTA (or radio?) it will carry?


Re: new FYSETC S6 build

Khalid Baheyeldin
 

In another thread Markus wrote:

I also tried the GPS change to RX3 again without success.

...#define TIME_LOCATION_SOURCE          GPS #define SerialGPS Serial3 #define SerialGPSBaud 9600

 

The GPS TX goes to RX3 PC11 on EXP1 left row second pin from top.

Markus,

Did you refresh your OnStep version from the latest master?
It has a change for not using Serial3 as a command port, and that allows it to work for the GPS.


Re: OnStep Configuration Generator lives on ...

Khalid Baheyeldin
 

On Wed, Jul 29, 2020 at 04:47 AM, Howard Dutton wrote:
OnStep requires no additional values for the the TMC5160 vs. the TMC2130, if you don't specify the current it falls back to 600mA and OnStep provides a warning on compile.

And sure one should specify IRUN, but that's the only other option most need for decent performance.  If they want to mess around with IGOTO and IHOLD they're tuning and compiling/uploading/testing several times probably at that point and who cares then.
The default Config.h has all the I* parameters set to OFF.
If this works, with a compile warning, then I can add the TMC5160 without having to ask for the values for each of the I* values.
Should I?

I didn't look at the OCG and how you set this up... but it should would be nice to grab an Config.h file and turn it into a template then parse the file to insert the values.
That is exactly how I am doing it in this refresh/re-design. The values that will be set by the OCG are tokenized, and the OCG replaces those tokens.

The new format of the Config.h lends itself well to this. I have two Config.h templates, one for 3.16 and another for master.

The only thing I added is the two lines for the GPS serial port and baud rate. Nothing else was changed.

Of course, this is all a point in time thing, and if new variables are introduced I have to merge them (in the master template).


Default limits

Jamie Flinn
 

Hi All…

 

I am setting up  a workaround for the PARK/UNPARK crash in Kstars/EKOS and trying to find a suitable and reliable LIMIT I can set that say, stops tracking or even better auto parks  (since I CAN kill Kstars/EKOS via end of schedule process that is still working)

 

Normally I would just unpark at start of schedule and park at the end then power off in the morning…..

 

Overhead limit I have set to 90 so that EKOS meridian flip can happen – so is there a horizon limit that will trigger a stop in tracking (at all times! – trying to avoind crashing the scope inot the ground)

 

Thanks in advance

J

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