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INDI Library v1.9.6 Released (21 May 2022)

Bi-monthly INDI Library released with new drivers and bug fixes.

INDI focuser driver for Waveshare Stepper Motor HAT for Raspberry Pi

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  • Thank you received: 78
Barry,

That motor should be fine. In the default 32x microstepping configuration, it might move a little slow. If that turns out to be the case, you can change the DIP switches on the Waveshare HAT to a lower microstepping factor, to speed things up. You will need to modify the #define MICROSTEPPING at the top of the source code file to match the DIP switches, and rebuild the driver. But it will work as is, maybe just a little slow.

-- Kevin
The following user(s) said Thank You: Barry Dyer
7 months 2 weeks ago #76237

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Hi Kevin
Firstly a huge thank you for the work you've done on this driver.  It's been a lot of fun playing with getting this working on my Raspberry Pi 4 and StellarmateOS.  I have a question on microstepping and I suspect I am missing something elementary.  I have a 1.8 degree (200 steps/rev) Nema14 motor that I am trying to pair with my SVX102T refractor.  My scope has a CFZ of 111 microns and I am trying to achieve the recommended 10 steps per CFZ.  I believe that using 1/8 steps should achieve this goal, but I am a loss as to how to make the driver do this.  I tested with the Waveshare Python code (which needed to be corrected for the active high enable pin) and was able to make the stepper motor do a 1/8 rev with 200 steps:
    Motor1.SetMicroStep('hardward','1/8step')
    Motor1.TurnStep(Dir='forward', steps=200, stepdelay = 0.0001)
    time.sleep(0.5)
    Motor1.TurnStep(Dir='backward', steps=200, stepdelay = 0.0001)
    Motor1.Stop()
Questions:
  1. To make this work for the focuser, I changed the MICROSTEPPING define in wmh_focuser.cpp to 8 and set the dip switches to 110 on the board.  However, this still yields a full turn for 200 steps when I test using the Indi Control panel for the focuser. I'm sure I'm misunderstanding the intent of the MICROSTEPPING define, but for the life of my I can't figure it out. 
  2. I then figured I could put the motor onto the fine focus knob, but wouldn't that make focusing really slow?


 
5 months 1 week ago #78508

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I believe the way microstepping was implemented in the driver is for smoother and quieter motor movement rather than added precision. And a microstep position can only be held with constant power to the motor, which is not desirable. Your options are therefor to use gear reduction and backlash compensation.
INDI/KStars on Raspberry Pi 4, 4gb
Raspbian Buster with AstroPi3 script configuration
Skywatcher HEQ5 Pro Mount
Canon 600D Camera
Orion SSAG/ASI120mm @280mm Guide Scope
PHD2
Waveshare Stepper Motor Board - DIY Focuser
Adafruit GPS Module
Generic Bluetooth Joystick.
Startech 7 port powered USB Hub.
The following user(s) said Thank You: Anand Narwani
5 months 1 week ago #78544

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I've been playing around lately with the hardware DIP switches, and I found that the Modes switches are orientated in a very non-intuitive way.
Switches 123 belong to motor 1
Switches 456 belong to motor 2
The Mode table is organized as Mode 2, Mode 1, Mode 0 in the documentation. I found they actually correspond to the DIP switches in reverse order.
Mode 0 is switch 1 and 4
Mode 1 is switch 2 and 5
Mode 2 is switch 3 and 6

So to set it for 1/8 step you need to set DIP 1, 2, 3 to 1, 1, 0 respectively.

  
INDI/KStars on Raspberry Pi 4, 4gb
Raspbian Buster with AstroPi3 script configuration
Skywatcher HEQ5 Pro Mount
Canon 600D Camera
Orion SSAG/ASI120mm @280mm Guide Scope
PHD2
Waveshare Stepper Motor Board - DIY Focuser
Adafruit GPS Module
Generic Bluetooth Joystick.
Startech 7 port powered USB Hub.
Last edit: 3 months 4 weeks ago by Andrew.
3 months 4 weeks ago #79780
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Eureka!!!
Stubborn as I am I wanted to try the waveshare stepper hat again; all worked out perfectly. Soon the report with 150PDS
Ettore
INDI/KStars on Raspberry Pi 4, 4gb
Raspberry Bull 64bit
Skywatcher 150PDS
CGE-PRO Mount
Nikon D5300 Camera
ZWO ASI120mm
Guidescope: Tair 3-A 299mm
Whaveshave focuser
3 months 2 weeks ago #80361

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  Kevin,
Can't tell you how much I appreciate the work you have done on the Waveshare Hat focuser module.  I have been working on fabricating a motor bracket for my 1990's C8 and a Nikon 70-200mm F2.8 lens.  Attached photos of the completed brackets and presently performing software calibrations for travel parameters before attempting outdoor focusing tests.
I am using a 5:1 pulley reduction on the C8 and a 6:1 reduction on the Nikon lens.
Thanks again!
Bill G

   
Last edit: 2 months 2 weeks ago by Bill Glynn.
2 months 2 weeks ago #81171
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I'm glad it's working for you. I can't see your pictures, they say "You do not have permissions to access this page."
2 months 2 weeks ago #81203

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Kevin,
I see that your RPi4 is attached directly to the scope. Does it have a cooling fan and if so are there no vibration concerns? I would love to fasten it to my mount but was concerned about vibration?
Bill G
2 months 1 week ago #81232

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Now I see your pictures. Nice 3d printed brackets :)

My Pi does not have a cooling fan. I never have problems with it overheating. But I don't live in the desert, where it can be 100 degree F at midnight.
The following user(s) said Thank You: Bill Glynn
2 months 1 week ago #81234

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