Yet another DIY auto focuser, this time using an off the shelf all in one PCB by Big Tree Tech.

[PlankWithANailIn]

Hi all,

Long time lurker here, this post is going to be a bit disjointed sorry never done anything like this before.

Over the pandemic I took up multiple hobbies two of which were astronomy and 3D printing and I have learned a lot from forums like this and others so thought that I would give back with a project my eldest son and I have been working on. At the end of the pandemic my son was finishing up his A levels one of which was computer science we thought it would be a good idea for him to complete a non school project to help with his application to university this coincided with me purchasing a PCB for my DIY 3D printer that attached to its tool head to control the extruder with a stepper motor controller and microcontroller all on one board. At the time I was aware that the DIY community was creating its own computer controller focusers and thought that this PCB would be super useful but no one was using it. 

The board in question is the Big Tree Tech EBB 36 PCB. 

BIGTREETECH EBB 36/42 Can Bus U2C V2.1 for Connecting Klipper Expansio – Biqu Equipment

It has an unbelievable low price of £10, which is lower than an Arduino Nano and it has a motor controller on it and multiple mosfet's for controlling fans and heating elements, an absolute bargain. 

So my son and I decided we would workout how we could use this PCB to control a focuser, I would create the 3D printed case and he would provide the firmware and ASCOM driver. We quickly discovered an open source project, STM32duino (github.com),  that enabled this board to be used with the Arduino IDE. We threw together some software and a case put it all on github and awaited the results of his application to university and in the end none of them asked him for interviews and all offered him places at achievable grades, that was over a year and a half ago now.

Now that he has finished his first year of university we decided to finish this all off trying to make it look like a fully completed open source project to help with his CV when applying for a job in his sandwich year. After a month of work we have beaten the project into a finished state and are ready to publish. 

The finished project can be found on github here.

https://github.com/RealtaScopeTech/Realta-EBBfocuser

As a family we have Irish/English and Chinese Malay ancestry and settled on the name Realta as it means star in Irish. 

The project has been released under the MIT license that basically means you can do anything you like with it just provide attribution.

I have attached a few images of it to this post and proof that it passes ASCOM testing. I the wild we have only tested it with N.I.N.A and it works ok for us and our MAK127. We have a bit of an issue with Windows not liking the installer that comes packaged with ASCOM, any advice on how to stop Windows thinking this is a virus would be super helpful!

[PlankWithANailIn]

Hi all, small update to the git hub repository to remove the .exe and include a manual driver install method that doesn't trigger the wrath of Windows.

[CedricTheBrave]

Very well designed and written well done

 

[Boron]

A nice project!

Whats the expected all up costs for a single motor unit?