Another SGL Arduino Focuser underway

[astrovirus]

So I also took the plunge and started construction of my ASCOM focuser based on the exellent SGL design. I ordered these steppers, an Arduino Uno, an EasyDriver, axis coupling. For my mounting bracket I took a spare piece of copper I had laying around (left over form my TEC cold finger on the 350D) and drilled in the holes for the stepper axis and stepper mounting holes.

Next will be mounting them to my scopes.

To be continued....

Regards Tim

[ncjunk]

have you got the steppers working ok with the software?

how are you planning on running two together?

looking good though!

[astrovirus]

Hi Neil,

Steppers shouldn't be a problem as they are the same ones as you use. For now, I'm not planning on using them alongside eachother as I switch between scopes when imaging depending on the target. So I'll have 2 identical configurations with one controlerbox which I will swap out between scopes. The dual configuration will probably come into play in the future, when I realize my observatory and can mount my scopes permanently. The electroninc part will go next after I get them connected to my scopes.

[JamesF]

I shall follow this with interest.

If the weather doesn't improve soon, SGL members are going to have some of the best kitted-out telescopes in amateur hands

James

[Gina]

C

If the weather doesn't improve soon, SGL members are going to have some of the best kitted-out telescopes in amateur hands

James

I think so too. I'm already adding cooling to my second DSLR to use for wide DSOs plus tidying up my first. Also been making numerous small improvements to my observatory and warm room.

[cthorpey]

Will be following this with interest.

[ncjunk]

Hi Neil,

Steppers shouldn't be a problem as they are the same ones as you use. For now, I'm not planning on using them alongside eachother as I switch between scopes when imaging depending on the target. So I'll have 2 identical configurations with one controlerbox which I will swap out between scopes. The dual configuration will probably come into play in the future, when I realize my observatory and can mount my scopes permanently. The electroninc part will go next after I get them connected to my scopes.

post all your results please! i have my stepper (same as yours) direct coupled to the ed80 but the c11 with a longer focal length has a geared stepper.

what are the two scopes you are using?

[astrovirus]

post all your results please! i have my stepper (same as yours) direct coupled to the ed80 but the c11 with a longer focal length has a geared stepper.

what are the two scopes you are using?

I was already intending to post my entire progress here, as the support for this project is supurb. My scopes are an 8" newton (f 1000mm) and an 70 ED (f 420 mm), so the newt is in between your C11 and ED80. I have calculated the critical focus zones for both scopes: 58-79 (blue-red) microns for the newt and 83-114 microns (blue-red) for the ED70 using the calculator at the botom of this page and with the pixel size (6.4 micron) for my Canon 350D and the focal ration as input. Am I correct that the gearing is needed when the steps including microstepping are bigger then the critical focus zone of the scope? So I would need to calculate my micro step size in microns then.

In the mean time I have made some progress today. Cut the brackets to size and drilled the mounting holes, after which 1 hole needed a little finetuning as I don't have a drilling stand and do everything by hand. Both brackets now fit nicely on their respective focusers. Only need to mount the connectors for the electronincs to the steppers, which will likely be of the RJ11-type.

To be continued.....

Regards Tim

[themos]

Looks great!

[ncjunk]

very nice! puts my bent bit of scrap metal to shame

[Leo.A]

That's a very nice looking set up!

I particuarly like the little universal joint you have used, where are they available from, or more appropriate for me in Australia, what is it called (besides universal joint) so I could chase up similar (we don't have the same suppliers here)

What are the servos you have used?

I'm interested in doing something similar and my son will write the program for the uno or mega (I have no idea with programming) but I had no idea where to start.

[astrovirus]

@Leo.A, as I am in The Netherlands I have no idea where to get the joint I use in Australia, but try Ebay, you can get anything from there at low cost.

@Neil, It's still bent scrap metal although I agree the coper looks great.

Will start on the electronics on the next few days.

[astrovirus]

So, just got everything wired up in the Arduino/easyDriver control box last night with the skillfull help of a good friend of mine. Ready to start testing the system with my small 70ED scope over the coming days, followed by the 200P. Will keep you posted as the results come in (and questions likely). One thing that came to mind last night, was if i should do anything to the little pot on the easyDriver that controls the Amp output? At what setting would you recommend me to start when powering all upfor the first time?

[ncjunk]

I started it on Max for the Current regulating Pot and then lowered it until the motor started to operate incorrectly then increased it a bit. I wouldn`t

worry about it to start with, just leave it on max and check everything rotates and is working.

On the Geared stepper I have been using the power off signal on the Easydriver to disable the power after focusing (you will get a slight

shift in the focus postion when you next power it on as it settles into position) (I have it configured as Pin 4 in the Arduino sofware)..

[astrovirus]

OK thanks Neil, I'll start at Max current. My wiring also incorperated the power enable from pin 4, so that's taken care off.

Will keep you posted.

Regards Tim

[astrovirus]

OK,

So I ran into a problem with the software when uploading the SGL sketch into my UNO. I followed the getting started guide by the letter: installed the arduino software and tested with the blink sketch, all OK; Unzipped the Libraries.zip file and copied the folders AFMotor, eepromRW, and HalfStepper to F:\Arduino\arduino-1.0.1\libraries as specified; copied the file SGL_Focuser_Driver_nolcd_2_0_0I.pde to F:\Arduino\arduino-1.0.1\Sketchbook\SGL_Focuser_Driver_nolcd_2_0_0I; Opened the sketch and press upload.

Then this error log appears:

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:60:22: error: WProgram.h: No such file or directory

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp: In constructor 'HalfStepper::HalfStepper(int, int, int)':

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:80: error: 'OUTPUT' was not declared in this scope

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:80: error: 'pinMode' was not declared in this scope

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp: In constructor 'HalfStepper::HalfStepper(int, int, int, int, int)':

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:114: error: 'OUTPUT' was not declared in this scope

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:114: error: 'pinMode' was not declared in this scope

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp: In constructor 'HalfStepper::HalfStepper(int, int, int, int, int, int)':

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:145: error: 'OUTPUT' was not declared in this scope

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:145: error: 'pinMode' was not declared in this scope

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp: In member function 'void HalfStepper::step(int)':

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:169: error: 'abs' was not declared in this scope

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:179: error: 'millis' was not declared in this scope

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp: In member function 'void HalfStepper::stepMotor(int)':

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:219: error: 'LOW' was not declared in this scope

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:219: error: 'digitalWrite' was not declared in this scope

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:220: error: 'HIGH' was not declared in this scope

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:239: error: 'HIGH' was not declared in this scope

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:239: error: 'digitalWrite' was not declared in this scope

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:240: error: 'LOW' was not declared in this scope

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:267: error: 'HIGH' was not declared in this scope

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:267: error: 'digitalWrite' was not declared in this scope

F:\Arduino\arduino-1.0.1\libraries\HalfStepper\HalfStepper.cpp:268: error: 'LOW' was not declared in this scope

So now I am a bit stuck. Any help is much appreciated.

Regards Tim

[ncjunk]

Its a version 1.0 problem on the arduino as they changed how the libraries work....

I'll just have a look to refresh my memory..

[ncjunk]

Go to sgl Automation on the yahoo group and I have corrected the Library:-

In Arduino 1.0 IDE a reference file was renamed to Arduino.h so you now need to rename the header file or reference from WProgram.h to Arduino.h in each library.(I have just done this for all the libraries I am using.)

Sorry for that! I think I tested this with someone on another thread but must have left the faulty one on the server.

[astrovirus]

No problem Neil,

Just downloaded the new version and will test tonight, time permitting. Thanks for the quick response, this is a great project.

Regards Tim

[Neil I]

Hope it all works OK Tim. I'm also building a SGL Arduino focuser and just finished the soldering this evening. Hope to get it tested tomorrow. Fingers crossed

Cheers

neil

[astrovirus]

I am another step forwards, after downloading the new libraries, I was able to upload the sketch into the UNO. When I hooked everthing up, no movement what so ever. Luckily I remembered a discussion in the main Arduino SGL thread that suggested looking at the power down option, which I also put in place, so this morning I removed pin 4 from the Arduino and I had movement allright. Now I just need to put the code changes that Neil suggested in the main thread into the sketch to make the power down fuction OK and then just need to play a little with the current and pulse settings to make the motor run smoothly as this morning I did not (yet).

Will keep everybody posted here.

Regards Tim

[ncjunk]

I'll set up some test gear in the spare room and go through the software again. There are still a few errors kicking around by the looks of things.

[fwm891]

I remember there being problems with V 1.0 sometime ago and I use an older 22 or 23 version which drives mine very nicely - great project, great support

[ncjunk]

I still have problems solving storing the settings. The Visual basic user parameters don´t work correctly and the arduino

eeprom save function was causing problems. I´ll have another look over the next couple of weeks.

The version 1.0 caused a nightmare but now its a couple of versions in I had better check see how it operates.

I had some problems on Saturday for the first time in ages and it may have been because I had two versions installed.

I´ll let you know if I find anything.

[astrovirus]

Hi Neil,

What a great project. I just sorted out the minor issues I was having, and everything is operating as expected with my 70ED. What I did, was crank up the amps onthe Easydriver to full open as you suggested, and in the stand alone application icreased the speed to 1500. With the pin 4 disconected on the Arduino I got control, but the in/out was reversed, which was quickly solved in the sketch as documented in the project guide. Another thing I incorperated was the change in code you already suggested to another builder to make the power down down work. With this modified sketch uploaded to the Arduino it now works, thanks alot. Next will be the 8" newton. Microstepping with the 1600 microsteps also gives 1 revolution on the drive shaft, so mechanically everything looks OK too.

-edit, just been playing a little more with the speed setting in the stand alone application and it seems that anything between 1000-1500 driver the stepper OK below 1000 it stalls occasionally, and the sweetspot seems to be around 1200 for me. After some testing I now think speed set at 2000 works best, lower speeds showed minor stalls when the stepper was activated from the Arduino controled sleep mode, which doesn't happen at 2000. Should this have some implications when I might taken on the ASCOM control in the near future? Should I make changes to speed settings in the ASCOM application, or in the sketch, ornot at all?

Regards Tim