Arduino Nano, Telescope tracker

hello, i have just started getting back into astrophotography and would love to build a tracking system so i can take long exposures.

my idea was that,

i have a Arduino Nano, and a easy drive with a stepper so i can move it ever so slightly to keep the picture focused.

here is the lay out

breadboard, Arduino nano, 2 Easy Drivers, power supply,

now my questions are,

whats the easyest way to make it track this object?

can the nano take more than 2 easy drivers so i can add another motor for field rotation for longer exposure

and where would i start with coding, it would be better if i had all the stuff in front of me and i would just start playing around with the code till i got it to work

many thanks and hope someone has some helpfull answers

Matthew

whats the easyest way to make it track this object?

Step one is to define what "this" is.

can the nano take more than 2 easy drivers so i can add another motor for field rotation for longer exposure

Each EasyDriver needs two pins, step and direction. The nano has 14 digital pins and 8 analog pins, at least 6 of which can also be used as digital pins. You do the math. (14 + 6)/2 = ?

and where would i start with coding

void setup()
{
}

void loop()
{
}

hope someone has some helpfull answers

Should have put this first. Save me a lot of typing. :)

PaulS

thanks for you replys, sorry im new to the arduino board and as i said if i had it infront of me i would just get on with it and not create the thread unless im stuck on a particular problem.

the "This" could be anything i wanted star/planet/ ufo :P i just want to keep it in the field of view,

so i could have 10 easy drivers? if i could keep up with the voltage and current demand

I think motors/drivers wouldn't be an issue, but a "vision" sensor probably would be. Have you some ideas how arduino will "identify" an object in order to keep an eye on it's movement? May be some jpeg camera can go as "vision" receptor, and algorithm to recognize the brightest pixel will works, but I wonder how to "see" a black or gray object among others? Face recognition?

i was thinking some kind of ir sensor or something similar to that on the spotter scope ontop of the telescope that "sees" the object and trys to keep it in the sensor,

or i could go very basic and make it just move here at xyz speed slowly

i might want to impliment it into a goto system aswell, how can i make it so ascom sends commands to the arduino board?

for those who dont know

http://ascom-standards.org/

is there a SDK or some sort of way i can test this before actual implimentation?

Hi, Is the telescope on a equatorial mount?? If not, what mount system and degrees of freedom.

Have you googled some on telescope tracking?? Arduinos are being used for this…

it is a dobsonian on a normal mount

i did have a google search last night but i didnt really come up with much as i was tired

Start here: Google 'dobsonian arduino track'

What I've find out, there are two category:

  1. tracking telescopes not designed for astrophotography or for long-term tracking; http://www.bhphotovideo.com/c/product/681580-REG/JMI_Telescopes_LB12TNT_Train_n_Track_Motor_Drive_with.html
  2. capable to do it. http://www.opticsplanet.net/meade-8-lx200r-ritchey-chretien-telescopes.html

It looks like mechanics in this device would cost a fortune, and require periodic calibration. Never thought about such project as a hobbyist level.

most people use a eq platform but there are loads of problems with that telescope falling over and other stuff,

we were going to build another mount to make this idea work

ok so i got the arduino board setup with the easy drivers, and done a basic sketch but now need to write a Ascom Driver any help on where to start?

Hi Hallmat.

First you need to define whether you want this to be a stand-alone solution or connect it to a computer.

What do you currently have? Does you Dob mount have motors or did you want to motorise it yourself? If it has motors, is there an ASCOM driver?

If it has motors and an ASCOM driver already, then all you need is a guide camera connected to a PC (some webcams will do), free guiding software (such as PHDguide) and a serial cable between PC and and telescope. No Arduino needed in this case.

Without a PC this is going to be a lot more tricky, especially with an Alt-Az mount such as your Dob. I was considering something similar a while ago. I found out that there is a Video Experimenter Shield for the Arduino that can digitise a video source and is able to track objects in the video. You would then need a sensitive enough camera and feed the camera's video into the shield. However, the resolution of that shield is far to low for the tracking accuracy required for astro photography. See discussion here: http://arduino.cc/forum/index.php/topic,56049.msg480479.html

Even if the resolution was good enough, there is quite a bit of math involved to calibrate the tracking and then calculate the motor steps required to compensate.

You need to build a blob detection software. I recommend interfacing "processing"-soft name with arduino software. You shouldnt need object recognition but blob detection alone should be good enough. Processing has many good blob detection libraries you can use.

Have you seen this book, I have an early edition and it is very good:- http://www.amazon.co.uk/Telescope-Control-Mark-Trueblood/dp/0943396530

While not tracking I did do an electronic setting circles project back in 1993 - 1994 http://www.doc.mmu.ac.uk/STAFF/A.Wiseman/Acorn/BodyBuild/BB93.html

thank you all for your replies,

the steppers are going to be mounted on the dobs, but before we make it all up we make the new mount,

we were going to use PHDguide,

i have already ordered the telescope control book by mark & russle,

we would like this to be computer aided, we have all the circuitry made up and tested the arduino is amazing the amount of possibilities this tiny thing has,

many thanks for the replies

The “tracking” aspect of this sounds difficult to me. Your targets are very weak light sources, there are lots of decoys including big ones like the moon, and transient clouds will complicate things.

Once I tried taking pictures with an Infrared camera through a window. The images showed objects within the room reflecting off the glass but little of objects on the other side of the glass. You mentioned IR and I would suggest some quick tests before you go too far down that route. Some stepper motors have quite big steps so also check the gearing you use will give a smooth motion.

If you know the trajectory of the of the object then pre-programming the telescope motion may be the way to go.

Hello everyone,

Firstly, I'm new to the forum and to Arduino. I was wondering if this project ever got anywhere, and if it was a success. I am also planning something exactly the same using my Dobsonian telescope. I plan on making a new mount for my scope (I don't want to mutilate my existing Dob mount) and use either DC motors or stepper motors to drive it. I have already bought an Arduino UNO, Bluetooth module and some cheap 28BYJ-48 stepper motors/with ULN2003 Driver Boards. These are obviously too small for the job but bought them just for testing purposes. If any one has any fantastic ideas of how I could make this work, please let me know.

Apologies for resurrecting an old post - just thought it would save me explaining that's already been done.

Cheers.

Try this link: http://www.stellarjourney.com/index.php?r=site/equipment_onstep