Date   

Re: FYsetc S6 GPS

Khalid Baheyeldin
 

On Fri, Jan 14, 2022 at 02:11 PM, Chris Whitener wrote:
Kahlid
That is Khalid ... common error though ...

Did you move the GPS from RX3/TX3 to the softserial pins?
No.

was this done to shutup the incessant spewing from the GPS?
We only need the info once a night.

I have always used the following:

  #define TIME_LOCATION_SOURCE    GPS
  #define SERIAL_GPS              Serial3
  #define SERIAL_GPS_BAUD         9600

And wired it to PC10 and PC11 on EXP1, as in the pictures on
the Wiki page.

Once the GPS gets a fix and starts providing PPS, OnStep stops
reading that port, so the info from it is ignored anyway.


FYsetc S6 GPS

Chris Whitener
 

Kahlid, Did you move the GPS from RX3/TX3 to the softserial pins?
was this done to shutup the incessant spewing from the GPS?
We only need the info once a night.


Re: USB cables

Chris Whitener
 

The teensy has a trace to cut.  Rtfm.  The Fysetc board has a jumper.  Do not apply power while in usb position.


Re: Question on Torque, Currents, steppers, voltages, CONFIG settings

Guy Brandenburg
 

Hi, Ken,

Right now, we have taken absolutely everything off of the mount, except for some bolts: all four OTAs, all of the finders, all of the counterweights, the large steel plate all of that was bolted to, and even the cover for the Ealing counterweight box.

When the mount was last operational, we balanced everything on both axes and in all positions by adding or subtracting counterweights of various sizes and compositions, in various locations, and also by sliding some of them along special grooved racks we fabricated. And loosening and sliding and reclamping the OTAs as needed. If we attached any imaging gear, we re-balanced. (Or at least I did. I hope other users did so as well.)

Right now, during very preliminary trials, it’s not balanced at all in RA because the empty CW box sits on one side. The DEC axis is balanced because the six remaining bolts are evenly spaced. My next stop will be to fabricate and rig up an counterweight of some sort to balance out the empty Ealing counterweight box. Maybe this weekend. I wish it were not 50 miles away.

In raising a big weight with a penny, it’s like Archimedes supposedly said: all you need is a long enough (weightless) lever, or (I would add) the proper gear set, and almost no friction….

Sent from my iPhone, which capitalizes Weirdly & misinterprets words just To keep you on your toes


Re: Controller Time Drift

Khalid Baheyeldin
 

On Fri, Jan 14, 2022 at 10:36 AM, Vladimir wrote:
if your board have temperature compensated crystal oscillator of good accuracy then you don't need a PPS at all. MCU already getting CLK from that oscillator and there is nothing to sync. Just disable both options then.

For now you can run OnStepX on Mega2560 but in future that MCU may not be supported in favor of more capable MCU's.
OnStep does need a PPS source unless the board's clock is inaccurate.
It is true that the Arduino Mega 2560 clock is one such case.

But the MKS Gen-L has a good clock, and it should not drift. That is why Howard recommends it over plain Arduino.

At least that was the case until now.
Manufacturers may be cutting corners, who knows.

@planetibo
You should not just adjust the steps per degree and assume this will
fix the drift (if it is indeed drift). It may make the motors track better
but there is still the sidereal clock that OnStep internally computes.

If you have an operating system with Python 3.x on it, there is a drift test
included in my OnStep Python API. Run it if you can, and it will tell you
what is going on.


USB cables

Chad Gray
 

Hello, If i want to use USB serial to connect my OnStep computer via ASCOM/INDI to OnStep, are there OnStep computers that you cannot use a USB cable with power?  

Say i have my 12volt going into the board to power the steppers.  Can i use a USB cable with power also?

I smoke a Teensy SHC if i remember right when i first started so i have been paranoid about applying USB and Voltage at the same time on stuff in general.

Side question can you control OnStep with USB serial to the SHC?  Or do you have to plug in the USB to the OnStep computer to control it?

Thanks!
Chad


Re: Controller Time Drift

 

No, but if your board have temperature compensated crystal oscillator of good accuracy then you don't need a PPS at all. MCU already getting CLK from that oscillator and there is nothing to sync. Just disable both options then.

For now you can run OnStepX on Mega2560 but in future that MCU may not be supported in favor of more capable MCU's.


Re: OnStep Focuser support

George Cushing
 

These are still around for a couple of bucks


Re: OnStep Focuser support

George Cushing
 

Again I'd stay away from TIPs. No need to waste all that heat. IRL530 logic level MOSFETs will work nicely and the diode are included. 




Re: Controller Time Drift

planetibo@...
 

On Fri, Jan 14, 2022 at 03:48 PM, Vladimir wrote:
First you need to define RTC source in order to initialize 1Hz square wave signal to be used as PPS source. If you have DS3231 on I²C bus it would go something like this:
#define TIME_LOCATION_SOURCE DS3231

And your RTC (i.e DS3231) SQ pin must be connected to appropriate GPIO pin, not just I²C bus. BTW I am not sure OnStepX is good idea with Mega2560 MCU. You should probably stick with OnStep 4

MKS Gen-L v2 have a crystal oscillator.
Can we use crystal ocillator as a pps source? Or the Mega2560 should be synchronized with the crytal oscillator?

Why can't I run OnstepX on the Mega2560? The workload looks ok in the SmartWebServer interface.


Re: Controller Time Drift

planetibo@...
 

Currently I am at 26667 steps/°:
#define AXIS1_STEPS_PER_DEGREE 26667
 
I have a drift of about 11.4 "/ min, or about 1.27%.
 
I will try to configure at 27000 steps per °:
#define AXIS1_STEPS_PER_DEGREE 27000


Re: Controller Time Drift

 

On Fri, Jan 14, 2022 at 02:07 PM, <planetibo@...> wrote:
#define TIME_LOCATION_SOURCE OFF
#define TIME_LOCATION_PPS_SENSE HIGH
 
First you need to define RTC source in order to initialize 1Hz square wave signal to be used as PPS source. If you have DS3231 on I²C bus it would go something like this:
#define TIME_LOCATION_SOURCE DS3231

And your RTC (i.e DS3231) SQ pin must be connected to appropriate GPIO pin, not just I²C bus. BTW I am not sure OnStepX is good idea with Mega2560 MCU. You should probably stick with OnStep 4


Re: Controller Time Drift

Chad Gray
 

Having done clocks in HTML/Javascript they are not accurate.  Well, they are susceptible to in-accuracy.

My only input is to double check that the time on the computer is the same as the web browser. 

Chad


On Fri, Jan 14, 2022 at 8:07 AM <planetibo@...> wrote:
Hello,
I use this topic because I have a problem with time drift and therefore an RA drift at -11"/min.
I am using an MKS Gen-L v2 with OnstepX.
Normally the crystal oscillator should avoid time drift?

Here is the drift in time after 2 hours of running (at the biginning i do a "Sync with browser"):
Site:
  1/13/22 22:51:51 UT (web browser)
  1/13/22 22:51:12 UT (06:49:12  LST)
Here is my configuration for the PPS part in the Config.h:

#define TIME_LOCATION_SOURCE OFF
#define TIME_LOCATION_PPS_SENSE HIGH

I don't know if the Mks Gen-L v2 use correctly the Crystal Oscillator?


Re: Controller Time Drift

planetibo@...
 

Hello,
I use this topic because I have a problem with time drift and therefore an RA drift at -11"/min.
I am using an MKS Gen-L v2 with OnstepX.
Normally the crystal oscillator should avoid time drift?

Here is the drift in time after 2 hours of running (at the biginning i do a "Sync with browser"):
Site:
  1/13/22 22:51:51 UT (web browser)
  1/13/22 22:51:12 UT (06:49:12  LST)
Here is my configuration for the PPS part in the Config.h:

#define TIME_LOCATION_SOURCE OFF
#define TIME_LOCATION_PPS_SENSE HIGH

I don't know if the Mks Gen-L v2 use correctly the Crystal Oscillator?


Re: Connecting pwr ground to positive

kevin
 

Hi Paul,
Found  your messages in spam folder and hopefully sent you a reply

The 3.3V generated on the blue pill is the rail labelled VCC that is the supply for everything except the Wemos D1 Mini which generates its own from the 5V supply.

As noted in the Wiki,  the diodes are  require for the TMC drivers in the case that you only have the USB plugged in and no external power
Stepper driver section: Axis1/2 (RA/Dec or Azm/Alt): Axis1 and Axis2 each consist of:
  • A 1N4001 diode D20 (marked on the PCB back, but shown graphically here near the U3 marking) pulls VMOT up when only VIO is present, as TMC drivers require this.


Re: Connecting pwr ground to positive

Apollo Grandad (Paul)
 

Here's a simple video of reverse voltage protection:

https://youtu.be/IrB-FPcv1Dc


Re: Question on Torque, Currents, steppers, voltages, CONFIG settings

Ken Hunter
 

Guy, etc...

2 points to make...

1. The steppers on the bench... If they will not run at Guide or Slewing speeds on the bench
then they will surely NOT be able to drive the Telescope mount out there in the cold.

2. Guy said the mount was balanced... I am having horrible dreams thinking that the mount
counterweight is hanging down with the Dec Axis pointed straight up with no scope attached.
Please tell me this is not the case and how the mount balance was obtained.

If the scope Axis (RA AND Dec) is not precisely balanced it will be very difficult for the stepper
motors to overcome the imbalanced condition. Even changing from a 1-1/4 eyepiece to a 2"
eyepiece can cause enough of a balance problem to make movement difficult depending on
how far the eyepiece is from the Axis.

Guy... If you have any docs on the mount maintenance or especially the method for balancing
the mount, please send me a copy or link to it.

I am willing to chat with you guys all day if necessary to walk you through setting and checking
the mount balance but... Only if the mount has ALL scopes and instruments installed as if you
were going to do an actual observing session AND you have a few others there with you so they
can help and also learn the process.

A Penny can lift a 10 pound weight ! Ask me to prove it.


Re: Connecting pwr ground to positive

Apollo Grandad (Paul)
 

Kevin,

I know the STM blackpill module has a 3.3V regulator - surely that should generate the common 3.3V supply? (which the cpu may be hardwired to)

What confuses me are the Schottky diodes that link 3.3V to the higher voltage lines, in the maxstm circuit. Looks risky?

Diode bridge and USB opto-isolated data lines get my vote. External servo/stepper driver modules have opto-isolated signal lines.

Btw I've sent you 2 emails about the pcbs. Check your spam folder!

Cheers 
Paul 
 


How to double increase torque with silent stepper driver LV8729 #bluepill #configuration

quoctan91@...
 

Hi everyone, i have a question and need your support, please help. Im building my FORK mount ,it will carry a 20kg binoscope and maybe bigger equipment in future. I already have two 57x57 1.5A step motor that make me concern about the torque because it's all small motor . Besides, i have two LV8729 that saticify me with its super silent operation.
So, i have an ideal to double increase torque power for two axis. This will be two 57x57 step motor with two LV8729 driver for axis 1 and the same configuration for axis 2.
My questions is :
1. For examples bellow circuit, can i use both two LV8729 with two motor for 1 axis at same time ?
2. For big ,heavy system, if i have good mechanical design, can i use small and low torque stepper motor ?
Thank you.
Tan.


Re: Having a rough time with geting the web server working on the wemos esp8266, curious of a couple things I havent come across in the writings yet...

pepsiaddict@...
 

oddly enough, it works fine when not installed on the PCB, and just jumpered to rx and tx and powered through usb connection back to PC...will test more tonight to try and figure out the cause

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