Siguy
Posts: 4
Joined: Tue Aug 02, 2011 4:18 am

Re: Telescope GoTo controller

Sun Aug 14, 2011 4:45 pm

This is something the Raspberry Pi may or may not be suited to, and is probably overkill for. I was imagining that it could be connected to a motor-driven telescope mount, fitted with a small LCD and numeric keypad (or touchscreen) and programmed with a large celestial object database, which could potentially be an extremely powerful GoTo system. For comparison, the Meade Autostar computer in the telescope I own uses a Motorola 68HC11 with 32k RAM and 1mb flash memory, with a 16 x 2 character display. It has a surprisingly large amount of features, and something like 40,000 objects built in, but imagine what a 700mhz ARM controller with several gigabytes expandable storage could do!

I'm envisioning it as being more of a general purpose telescope computer, that could be used not only as a standalone GoTo system, but also as a hub for remote telescope control, an autoguiding solution, and more. It could display a full star chart, perhaps using a modified version of Stellarium, and therefore greatly improve ease of use.

Just a somewhat interesting idea I had...

Michael
Posts: 340
Joined: Sat Jul 30, 2011 6:05 pm

Re: Telescope GoTo controller

Sun Aug 14, 2011 5:42 pm

(for the non-astronomers, a goto mount is a set of motors, a computer and some firmware that together automatically move the telescope so it is always pointing at the same point in the sky (called autoguiding), even though the earth is rotating and moving through space. It can also be used to tell the telescope to 'go to' a particular celestrial object (galaxy, star, planet, etc)).

Actually, I think the Raspberry Pi would be very well suited to that task. The advantage of using something like Raspberry Pi is the extra horsepower can be used for all manner of other interesting tasks such as live tweeting your direction or pointing your telescope in the direction indicated in someone else's tweet. The social media and collaborative possibilities are engrossing.

With a camera attached to your R.Pi, you could even combine the observations of lots of astronomers around the world (think amateur very large array) all pointing at the same location in the sky at the same time and then crunch the data (on a server) to produce a composite image.

It would also be interesting to consider how this could be fed back into Education. Most schools in the UK probably couldn't afford a telescope let alone a goto mount for one, but like robots, stargazing is probably one of the best ways to capture children's imagination and interest in the sciences. Add in that schools usually assemble during the day and are usually located in built-up areas affected by light polution. Still, the possibilities are intriguing.

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
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Re: Telescope GoTo controller

Sun Aug 14, 2011 8:07 pm

Good idea. My Celestron C8 Goto controller is a bit clunky with its limited display etc. Always takes me ages to find the option I want (probably because I don't get it out as much as I should) Perhaps this would be the incentive for me to get out more! Michael's ideas are also intriguing.

James
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed.
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obarthelemy
Posts: 1407
Joined: Tue Aug 09, 2011 10:53 pm

Re: Telescope GoTo controller

Sun Aug 14, 2011 8:35 pm

is a gosub the same thing, but for a sonar ?
This programming thing does seem to be coming back !
(you may delete this silly post)

rmike
Posts: 41
Joined: Mon Aug 22, 2011 10:50 am

Re: Telescope GoTo controller

Mon Aug 22, 2011 8:36 pm

Hi guys,

the alpha board looks very promising :-) great work!
But back to the topic:
We are a bunch of amateur astronomers and are developing an open source / open hardware and quite powerful telescope control system called openDrive.
See:
[embed][/embed]
<- high speed goto demo with our alpha motor driver board
[embed][/embed]
<- slow speed up and down of a Escap P530 motor
http://opendrive.gizmor.org/fo...../index.php <- our forum (unfortunately mostly in German, but google.translator can help if needed)
https://github.com/selste/openDrive/wiki/Hardwaredesign <- our wiki
The hardware design is supposed to be modular, so different CPU boards could be used for different processing power demands.
https://github.com/selste/openDrive/wiki/Hardware <- Some pictures of the pcb stack.
SPI is used as the interface between the CPU board and our motor driver board.
Currently we are focused on a Cortex CPU but the rasberrypi board could really become an alternative ;-) for us.
It would bring a great amount of possible uses like USB-webcam auto-guiding for example, not to talk about all the other advantages having a real os with a network stack behind...
So - we really are looking forward to get our hands on your new linux board.
Question: Do you have info about boot capabilities of it at temperatures below 0°C ?
We could build a heater around it, but without it would be nicer of course.
Contributors and interested telescope makers are cordially invited to join us.

Michael

Michael
Posts: 340
Joined: Sat Jul 30, 2011 6:05 pm

Re: Telescope GoTo controller

Mon Aug 22, 2011 8:44 pm

Eben has said that the boards should happily work down to temperatures of at least -20 degrees C, subject to concerns about condensation. A heater might actually make condensation problems worse.

Please do keep us informed of developments. Do you have a twitter feed?

rmike
Posts: 41
Joined: Mon Aug 22, 2011 10:50 am

Re: Telescope GoTo controller

Mon Aug 22, 2011 8:54 pm

Hi Michael,

-20°C sounds good :-)
We have no twitter at the moment.

Michael

reggie
Posts: 151
Joined: Fri Aug 26, 2011 11:51 am

Re: Telescope GoTo controller

Fri Aug 26, 2011 1:02 pm

Quote from Michael on August 14, 2011, 18:42
(for the non-astronomers, a goto mount is a set of motors, a computer and some firmware that together automatically move the telescope so it is always pointing at the same point in the sky (called autoguiding), even though the earth is rotating and moving through space. It can also be used to tell the telescope to 'go to' a particular celestrial object (galaxy, star, planet, etc)).
. Not being pedantic, but moving the telescope and making it point to the same spot in the sky is not called autoguiding :) Whilst it true that a lot of goto mounts have an ST4 guide port for autoguiding it's a complementary control of the motors that requires extra hardware to do the task, namely a 2nd telescope and a 'guide camera', or a guide camera and an 'off axis guider' attachment that splits a small portion of the incoming image off to the guide camera. the guide camera is usually controlled from a PC that can 'see' whether a star has moved or not and nudge the motors to put the star back in position.

Both of my telescopes have goto control via a PC already, so I'd be more interested in seeing linux software that hooks into uart to control the mounts, there are some superb projects already, http://eq-mod.sourceforge.net/ Eqmod is fantastic but it's windows only.

rmike
Posts: 41
Joined: Mon Aug 22, 2011 10:50 am

Re: Telescope GoTo controller

Fri Aug 26, 2011 7:32 pm

Hi,
the guide camera is usually controlled from a PC
In our openDrive project we hope to be able to move that part to the control based on the ras pi.
So there would be no need for a notebook in the field any more if a dslr is used for astro imaging.
Even things like auto alignment through the USB webcam using star recognition algorithms would be possible with that amount of processing power available...

reggie
Posts: 151
Joined: Fri Aug 26, 2011 11:51 am

Re: Telescope GoTo controller

Fri Aug 26, 2011 11:33 pm

Hi Mike, that is something I hoped to work on myself at some point, I can currently control my scope via a handset with onboard database, however the EQMod software increases the resolution of the motors and provides way better handling of alignment. So using something like you're proposing to control the guide cam would be something I'd be very interested in. I think atm. that wxastrocapture? works o linux so it's really a case of adding a screen to r-pi. Auto alignment certainly sounds interesting, real autoguiding would be neat too, like it picks a guide star for itself and starts guiding.

rmike
Posts: 41
Joined: Mon Aug 22, 2011 10:50 am

Re: Telescope GoTo controller

Sat Aug 27, 2011 10:22 am

Hi reggie,

Steffen, one of our co-developers, is contributing to the linux port of phd guiding.
http://code.google.com/p/open-.....d-guiding/
So there are many nice programs already available to be adapted for the raspi.
Hope compiling for the arm platform will not bring to much trouble...

Michael

reggie
Posts: 151
Joined: Fri Aug 26, 2011 11:51 am

Re: Telescope GoTo controller

Sat Aug 27, 2011 10:42 am

Hi Mike, tell steffen he's a sexy man for porting PHD :) I have a qhy5 camera, 1x philips SPC900nc webcam and 2x philips spc880nc cameras, is there a list of supported cameras anywhere? I saw the qhy5 looks supported in the screenshots on google code.

reggie
Posts: 151
Joined: Fri Aug 26, 2011 11:51 am

Re: Telescope GoTo controller

Sat Aug 27, 2011 11:31 am

My only issue with doing all of the astronomy stuff on embedded kit would be getting a reasonable planetarium app. running, they're usually heavy on the video processing, do you have any plans with regard to this? I currently do all of my astro stuff in windows, using starry night, phd guiding ascom 5 platform and EQMod drivers (via uart) for controlling the scope.

I guess stellarium would be the software of choice for linux, I'm just wondering if your kit would be modular? I would happily run a r-pi with PHD as a complement to a laptop running stellarium.

rmike
Posts: 41
Joined: Mon Aug 22, 2011 10:50 am

Re: Telescope GoTo controller

Sat Aug 27, 2011 12:08 pm

Hi reggie,
i forwarded your camera question to Steffen...
Regarding planetarium app:
In my opinion it does not make much sense in our case (mobile astronomy) to build a whole pc from parts (raspi, keyboard, monitor) and use regular pc software on it. Doing so makes more sense on a regular notebook.
The main task for the raspi-control will be to automate the (phd) setup and the alignment procedure.
I would prefer to have the planetarium app on an iPad or android connecting to the control and having a regular (robust) handbox with a small display to move and setup the mount control.
I'am currently developing a wireless handbox for this.

Michael

reggie
Posts: 151
Joined: Fri Aug 26, 2011 11:51 am

Re: Telescope GoTo controller

Sat Aug 27, 2011 2:54 pm

indeed, I wasn't sure how you were breaking things down, with regard to how I do things, I use a laptop and a playstation 2 controller and starry night, with PHD doing the guiding, the ps2 controller is interfaced through the EQMod ascom driver. so at the moment PHD on the r-pi and the planetarium app on my laptop sounds like a good combination for now. Have you thought about bluetooth and a wiimote as a handcontroller ?

rmike
Posts: 41
Joined: Mon Aug 22, 2011 10:50 am

Re: Telescope GoTo controller

Sat Aug 27, 2011 3:49 pm

Hi,
Have you thought about bluetooth and a wiimote as a handcontroller ?
not for our cortex cpu board, but for the raspi together with bt hid available... why not, thanks for the hint.I found some videos about in on youtube:
You are cordially invited to join our forum. Maybe it will be better to discuss topics not directly related to the raspi there.

Michael

EDIT: I just checked the look and feel of these wiimotes in a local store and do not think that these could really be useful in the field. The push buttons are way to tiny for my fingers. No way to use these in winter with gloves as they come of the shelf. One could of course take out the electronics and put it in a decent box with some nicer buttons.

User avatar
Gert van Loo
Posts: 2487
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Contact: Website

Re: Telescope GoTo controller

Sat Aug 27, 2011 7:55 pm

Humm.. We have no microphone input. But we should have enough CPU power for speed recognition: Up, up,. up a bit, left, left, hold!

rmike
Posts: 41
Joined: Mon Aug 22, 2011 10:50 am

Re: Telescope GoTo controller

Sat Aug 27, 2011 9:45 pm

[embed][/embed]
:D

oconnor_paulQ
Posts: 1
Joined: Sat Aug 27, 2011 11:56 pm

Re: Telescope GoTo controller

Sun Aug 28, 2011 1:09 am

satellite tracking could be another interesting application


reggie
Posts: 151
Joined: Fri Aug 26, 2011 11:51 am

Re: Telescope GoTo controller

Sun Aug 28, 2011 11:45 am

Quote from rmike on August 27, 2011, 16:49
Hi,
Have you thought about bluetooth and a wiimote as a handcontroller ?
not for our cortex cpu board, but for the raspi together with bt hid available... why not, thanks for the hint.I found some videos about in on youtube:
You are cordially invited to join our forum. Maybe it will be better to discuss topics not directly related to the raspi there.

Michael

EDIT: I just checked the look and feel of these wiimotes in a local store and do not think that these could really be useful in the field. The push buttons are way to tiny for my fingers. No way to use these in winter with gloves as they come of the shelf. One could of course take out the electronics and put it in a decent box with some nicer buttons.

At my last place I used to run everything out of the cat flap, so never had to worry about gloves :)

selste
Posts: 1
Joined: Sun Aug 28, 2011 11:27 am

Re: Telescope GoTo controller

Sun Aug 28, 2011 1:04 pm

Hi,
Michael asked me to do a little promotion for OpenPHD ... :)
Quote from reggie on August 27, 2011, 11:42
[...] I have a qhy5 camera, 1x philips SPC900nc webcam and 2x philips spc880nc cameras, is there a list of supported cameras anywhere? [...]
Yeah, documentation is a bit sparse, i have to admit ...
Well, for the Linux port of OpenPHD Video For Linux Version 1 and 2 devices are supported as well as cameras that can be accessed/controlled via INDI.
I think starting with Kernel 2.6.38 or 2.6.39 Version 1 of V4L is no longer supported which means a couple of the older webcams are no longer working because the drivers haven't been updated.
Those Philips cameras should be ok to use (with the pwc kernel module), but there's no V4L support for the QHY5 (You could try qastrocam which uses a low-level driver specifically for this cam).
As a sidenote - we might switch to unicap (http://unicap-imaging.org/) as a more high-level API, i'm working on porting the relevant parts, but it's not yet finished.
Regards,

Steffen

thepanoguy
Posts: 17
Joined: Mon Sep 12, 2011 1:59 pm

Re: Telescope GoTo controller

Wed Sep 14, 2011 12:37 am

Have a look at the Panogear, Merlin, Orion, Papywizard project at the following site:
http://www.kolor.com/forum/
The chances are you will be able to use parts of that project in your application.

rmike
Posts: 41
Joined: Mon Aug 22, 2011 10:50 am

Re: Telescope GoTo controller

Wed Sep 14, 2011 8:31 pm

Hello thepanoguy,

i took a quick look at the above forum but do not see real synergies with our project.
We have a 5A stepper motor driver board with 64 micro step resolution and high speed operation working nicely.
All open source and open hardware btw. and intended at least for me for educational purposes.
We hope to use the computing power of the raspi for things like:
- USB webcam support
- image recognition (automatic star alignment, pointing model parameter gathering, etc.)
- tracking algorithms
- networking access

The necessary astro math lib could be the NOVAS lib (http://aa.usno.navy.mil/softwa.....c_info.php) or some equivalent like http://libnova.sourceforge.net/

Contributors and interested (amateur) telescope makers are cordially invited to join.

Michael

botdream
Posts: 19
Joined: Mon Sep 12, 2011 1:09 pm
Contact: Website

Re: Telescope GoTo controller

Wed Sep 14, 2011 11:24 pm

Hi rmike,

I'm currently prototyping a camera position solution for Panoramic Photography (just the electronics part and Embedded system), and I'm testing the Step Motor driver from TRINAMIC, using the TMC249 Eval kit board, one of the chips that the OpenDrive uses, I have a microcontroller running the low level SPI commmunications with the TMC249 to make the step motor run, and using some Linux Embedded board for the high level control (that I'm replacing with the Raspberry PI). The idea is to command the step motor position from a mobile device or even from a laptop, but using a browser as the user interface, making it simple to use it on the field ... well, not getting into much details, I'm already a bit off-topic (I apologize).

My question, Is it possible for me to use one off the OpenDrive Hardware boards, just to get things up and running in this prototype stage, I saw this board and it looked something that I may use to replace the TMC249 eval board, I need to desing the TMC249 PCB interface between the Step Motor and microcontroller, but am a bit short on time:


Could you please give me some tips, should I create myself the TMC249 PCB interface, his there some affordable solution that I could use for a quick start (without using TRINAMIC expensive PANDrives).

Sorry (again) for the off-topic, this topic is pretty interesting, will sure keep an eye on this development!

Regards,
Nelson.

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