DIY Nano/Ascom focuser

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As I am blind as a bat (long sighted ) and find it difficult to focus correctly manually I decided I would have a go at creating a remote DIY Arduino Nano focuser with Ascom/Windows support as found on https://sourceforge.net/projects/arduinofocuscontrollerpro/ by Robert Brown.  Early testing was not good I managed to melt a solderless breadboard and blow up the DRV8825 driver - really must remember to check + and - connections before throwing the switch (my excuse is the writing on small boards are too small for me and I have to wear a magnifier to see it).

However I had a spare TB6560 stepper driver board ( a lot more robust , bigger,massive heat sink but with nice screw in terminals for connections) - wasn't sure this would work with Mr Browns code but to my surprise it did (after some head scratching) and with only 4 wires from the Nano to the tb6560 board and then a further 4 wires to the Nema 17 stepper motor and power(12v). Ok so far so good - next I tried driving the focuser when attached to a SW ST80 using a direct shaft coupler - knock me down with a feather it works. The only problem is that the TB6560 board has no way of setting microstepping by software - its all done by little switches on the board but I found that the 1/16 stepping was fine bearing in mind I wanted fine focus so was not to bothered about speed. Ok next test connect up Sharpcap with ascom focuser support defined - works well and to my surprise so did BYEOS. Then shock horror I could find no inbuilt support for Ascom focuser in PHD or Nebulosity 3.3 - surely not true - anyone know different  please let me know????.

 

I am now waiting on a nema17 bracket so that I can fix the Stepper to the ST80 and a module box to put the Nano and TB6560 in. 

 

Still need to test long distant USB support for the focuser but I can see no reason why that should be a problem as my Canon 100d works with BYEOS at 20m with Active cable and powered hub - famous last words!!!

 

As well as an Ascom driver there is a stand alone Windows program to control the focuser should some software not have inbuilt Ascom support.

 

The Nano has an inbuilt USB to Serial converter so just connects to USB port (with the right driver) and provides power to the Nano - The TB6560 is powered by the 12v DC (3a max) which in turn then powers the Stepper Motor

 

Also need to test the focuser on Windows 7,10 as its running on Vista at the moment but it should be ok - 10 we shall see.

 

Hopefully I saw be able to focus better by using the software aids in BYEOS and Sharpcap - and all remotely.

 

Costs are - £5 Nano MCU, £12 TB6560 board, £3 nema17 bracket ,Module box £10 - plus bits and bobs £5 - so about £40 and all parts are easily replaceable. 

 

If it all works I will post photo's and then I will be doing the same to my other kit. Thank you Mr Brown.

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Update - Works in Windows 10 but it didn't to start with - would connect then fall over with invalid response from Nano !.
Loaded Arduino IDE and then it worked ok - also put Pad on charge so could be a power issue. Still it works. Tested SharpCap and BACKEOS in Windows 10 and with the Ascom Focuser - no problems.

[+Graham]

Sounds good. 

Will have to look into this further. 

[Guest Astroboffin]

I use the same software produced by Robert Brown and is Superb I have built two stepper motor focusers from his instructions, and he is very very helpful if you contact him at all, answers email very fast, as I had a few issues, but all sorted now.

AB

 

 

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39 minutes ago, Astroboffin said:

I use the same software produced by Robert Brown and is Superb I have built two stepper motor focusers from his instructions, and he is very very helpful if you contact him at all, answers email very fast, as I had a few issues, but all sorted now.

AB

 

 

Yes agree RB is very helpful. I am working on using CNC RepRap set up to minimise wires etc so I am / will not be using his code exactly. Something like this hardware wise http://www.ebay.co.uk/itm/DIY-Laser-Engraver-control-board-CNC-Shield-V4-Nano-3-0-3pcs-A4988-CNC-/321916340595?hash=item4af3b58973:g:TuEAAOSw5ZBWQJW3

 The joys of "Open Systems".

Found making the telescope focuser brackets the hardest bit - as I am not a "Graham" - wish I were.

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ok finished mk1 and it works as either Ascom driven or stand alone using RBrowns program. Stop laughing at my bracket Graham - it was a fence post bracket before I bent it into a Z shape and fixed to my ST80 focuser. Nearly straight but will need some minor shimming to make it perfect. Runs well and can hold my DSLR when scope at 90 degree's.  I used the TB6560 shield and one of these http://www.ebay.co.uk/itm/Nano-Terminal-Adapter-for-the-Arduino-V3-0-AVR-ATMEGA328P-AU-/231847849110?var=&hash=item35fb356c96:m:mhBj-86R4YwOwU5B5KuHSEQ because I can't solder to save my life and both have screw terminals. It could all be smaller if I could :-) Now onto MKII which will use a plantary gear of 27:1 giving very small steps on my main refractor.  Can recommend Mr R Browns DIY Focuser - well written and fun to build. NB although I didn't use the DRV8825 driver as he did the TB6560 was driven without alteration to his code but I don't have software control of the micro stepping which to be honest I dont need so I just set the micro step size by switches on the board and set up to rough pre marked focus points to limit the travel/time.

 

https://drive.google.com/file/d/0B9aHac2P5RgVSnZyd3VqYUFSM1U/view?usp=sharing
https://drive.google.com/file/d/0B9aHac2P5RgVYnFUZ3RKM2lxLTA/view?usp=sharing
https://drive.google.com/file/d/0B9aHac2P5RgVMVFNbTF2MjQxV0k/view?usp=sharing
https://drive.google.com/file/d/0B9aHac2P5RgValpPbzR5OWdNVU0/view?usp=sharing