Since I aquired an Losmandy G11 mount without any goto provision I decided to create my own solution. I was a bit reluctant to use a Gemini, mainly because of the cost, but also due to the reliability since the servo motors are somewhat prone to failure. I also like to have complete control over the software/firmware so that no "show stopper" issues will ever be a problem for me. Looking around the 'net I saw other goto systems that seemed capable, but either they had needlessly complex hardware or were commercial systems that cost about twice what they should.
OnStep is a computerized goto system, usually for stepper motor equipped mounts though any step/dir interface motor driver (including servo) should work. It was designed, from the beginning, as a more or less general purpose system and provisions were made in the firmware to allow for use on a variety of mounts including Equatorial and Alt/Az (GEM, Fork, Dobsonian, etc.) It uses an LX200 like computer command set with a few extensions to suit hand controller-less operation.
There's a telescope hand controller App for Android (free in the Google Play Store,) an option to control through a website (Smart Web Server,) and a dedicated physical hand controller (Smart Hand Controller.) Or, on a PC there's ASCOM and INDI drivers for control. These options allow you to setup and control OnStep using a wide range of software including my Sky Planetarium, Cartes du Ciel, Stellarium, SkySafari, KStars, PHD2, etc. You can see most of the control possibilities in the diagram below:
Also, please visit my StellarJourney.comsite for updates, links toOnStep resources, my other astronomy software, or to see someImages taken with the assistance of my OnStep operated mounts.
If you find OnStep useful and would like to show your appreciation and support please consider making asmall monetary donation. This keeps me motivated and helps cover expenses associated with my projects.
My GPS does not appear to function and I note Khalid's comment here about defining the GPS serial port as
#define TIME_LOCATION_SOURCE GPS
#define SERIAL_GPS Serial3
#define
My GPS does not appear to function and I note Khalid's comment here about defining the GPS serial port as
#define TIME_LOCATION_SOURCE GPS
#define SERIAL_GPS Serial3
#define
A couple of thoughts.
I would worry that if one of the drivers missed a step pulse and they got out of sync the two motors could end up fighting one another. Some 3d printer boards (the FYSETC S6 is
A couple of thoughts.
I would worry that if one of the drivers missed a step pulse and they got out of sync the two motors could end up fighting one another. Some 3d printer boards (the FYSETC S6 is
Guy...
Do a Google search on Vexta Clean Damper for information on how the "flywheel"
actually works. DO NOT get isolation dampers that mount the stepper on rubber
gaskets. You need the shaft mounted
Guy...
Do a Google search on Vexta Clean Damper for information on how the "flywheel"
actually works. DO NOT get isolation dampers that mount the stepper on rubber
gaskets. You need the shaft mounted
Barry,
I am one of the few people that implemented encoders on my mounts. I have a couple of Losmandy mounts with Astro Devices 311,296 step encoders.
I am driving them through a Teensy 4.0 that is
Barry,
I am one of the few people that implemented encoders on my mounts. I have a couple of Losmandy mounts with Astro Devices 311,296 step encoders.
I am driving them through a Teensy 4.0 that is
Guy,
I found a web page with several of those steppers pictured on it. If that is a data, it has to be in the format YY/MM/DD as one of the pictured motors has a date of 10/12/28 and another one is
Guy,
I found a web page with several of those steppers pictured on it. If that is a data, it has to be in the format YY/MM/DD as one of the pictured motors has a date of 10/12/28 and another one is
I get it - you want to use something you are familiar with and comfortable with and you are not afraid of designing a board for this. It will be interesting to see how that set of parts gets mounted
I get it - you want to use something you are familiar with and comfortable with and you are not afraid of designing a board for this. It will be interesting to see how that set of parts gets mounted
I am in communication with someone that has first-hand experience with Ealing mounts.
His comments are that the mount could be ridden by someone and still be able to slew.
Guy has stated that the
I am in communication with someone that has first-hand experience with Ealing mounts.
His comments are that the mount could be ridden by someone and still be able to slew.
Guy has stated that the
The 6 to 15 deg/minute is only a ruff estimate using nema 17 steppers which are limited by the need for more torque (low rpms and torque small stepper need alot of reduction) to start and the mass of
The 6 to 15 deg/minute is only a ruff estimate using nema 17 steppers which are limited by the need for more torque (low rpms and torque small stepper need alot of reduction) to start and the mass of
This is basically the problem. At 15 degrees/minute, it will take 12 minutes to move 180 degrees. Are you ready to wait that long for it to move from the North American nebula to the Orion Nebula?
This is basically the problem. At 15 degrees/minute, it will take 12 minutes to move 180 degrees. Are you ready to wait that long for it to move from the North American nebula to the Orion Nebula?
Ken
Guy is 100% on the mark. I was there when Guy removed all the balancing weights on the RA axis. The DEC axis has no load at all. In this condition, I have tried to turn the worm that drives the RA
Ken
Guy is 100% on the mark. I was there when Guy removed all the balancing weights on the RA axis. The DEC axis has no load at all. In this condition, I have tried to turn the worm that drives the RA
External stepper drivers and paired with the right stepper has such a huge speed range. A good example is a nema 34 motor and driver on my router table. I can run at Cutting speeds as slow as .125
External stepper drivers and paired with the right stepper has such a huge speed range. A good example is a nema 34 motor and driver on my router table. I can run at Cutting speeds as slow as .125
Guy,
I found the stepper motor part number you are using on a Brazilian website. See the text highlighted in red:
Maybe this is why they stall so easily?
Bob
Description
Nema23 4Kgf Stepper
Guy,
I found the stepper motor part number you are using on a Brazilian website. See the text highlighted in red:
Maybe this is why they stall so easily?
Bob
Description
Nema23 4Kgf Stepper
Hi Guys,
I am after some guidance re: wireless SHC.
I have bread boarded 2 of them. Intend to make final on VERO (strip board).
CPU is ESP32…ESP-WR00m-32 or node MCU-32s
Currently using
Hi Guys,
I am after some guidance re: wireless SHC.
I have bread boarded 2 of them. Intend to make final on VERO (strip board).
CPU is ESP32…ESP-WR00m-32 or node MCU-32s
Currently using
One issue I see is that these external drivers do not allow changing the microstep rate dynamically for slewing vs tracking, so your slew rate will be limited. I looked at them a year ago when I was
One issue I see is that these external drivers do not allow changing the microstep rate dynamically for slewing vs tracking, so your slew rate will be limited. I looked at them a year ago when I was
Guy,
If you double the voltage, the current will rise to twice the value in a given time. If you terminate the pulse at a certain current, you will reach that time twice as fast (which means more
Guy,
If you double the voltage, the current will rise to twice the value in a given time. If you terminate the pulse at a certain current, you will reach that time twice as fast (which means more
I still don't see why you need a new board at all.
Using external drivers has been a feature of OnStep for quite some time now.
Again, you can do all of what you said with a normal OnStep board.
I still don't see why you need a new board at all.
Using external drivers has been a feature of OnStep for quite some time now.
Again, you can do all of what you said with a normal OnStep board.
Yes external drivers, no not like the one you linked. That is a servo driver, anything servo either ac or dc servo is a bit more expensive.
LV8729 - Amazon $7, Ebay $8. Limited to 0.8 amps cont, peak
Yes external drivers, no not like the one you linked. That is a servo driver, anything servo either ac or dc servo is a bit more expensive.
LV8729 - Amazon $7, Ebay $8. Limited to 0.8 amps cont, peak
David,
There seems to be a shortage of the TMC5160. I paid $17 middle of last year for a Bigtreetech TMC5160 V1.2. I believe they are up to V1.3 now, and I do see them from $30 to $47. Khalid
David,
There seems to be a shortage of the TMC5160. I paid $17 middle of last year for a Bigtreetech TMC5160 V1.2. I believe they are up to V1.3 now, and I do see them from $30 to $47. Khalid
