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INDI Library v1.8.5 Released (19 Apr 2020)

April 2020 release of INDI Library v1.8.5 introduces new drivers while providing fixes and improvements to existing devices and core framework.

DIY Focuser Arduino UNO with DC breakout, skywatcher focuser

3 months 2 weeks ago 3 months 2 weeks ago by sywong2000. Reason: typo
sywong2000
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DIY Focuser Arduino UNO with DC breakout, skywatcher focuser #52669
Hi Guys,

Just want to share a DIY focuser I built. I was thinking to get a electronic focuser for imaging session but I've found I've already got an old skywatcher focuser. I browse a little bit on the Internet and found there'a project by Wim van Berlo here: stargazerslounge.com/topic/297619-arduin...mpatible-dc-focuser/

which I'd think, yeah, why not just do the same thing? So I ordered some parts and build one myself, but without the HAT. I was trying to make the focuser as compact as it can be (I would have shrink it into a USB thumb drive size package, which is possible). I don't have a backyward site for astrophotography and I have to carry quite a lot of gears out to a remote site. So compact and lightweight are my priority. I figured out that I can just drive a TB6612FNG breakout directly with a UNO R3 (no HAT). The UNO got a 12V feed which also fits the motor requirement. See the photos in the attachments.

Basically everything is the same as what Wim has done, the arduino was uploaded with a sketch that handles the moonlite commands. I just need to modify the pin numbers to make it work.



I used a right-angled dupont pins and solder the breakout board right to the pins. This gives me a very compact size which I can fit the whole thing in any arduino UNO case:



Solder the RJ11 socket directly to the breakout. The skywatcher DC focuser uses a RJ11 to connect to the motor.



**NOTE the correction on the wiring as the picture described - on the first attempted I wired the 5V incorrectly to wired to GND.

Also the breakout board - caution when you feed 12V into it. I've broke two of the breakouts because the capacitor cannot handle 12V. (Caution: It would cause a blast with sparks when the cap blows!!!).. So make sure you check the cap before connecting 12V.

The UNO R3 case fits perfect on the position of the RJ connectors. I just need to open up a hole for connecting the cable to the jack



and that's the whole thing:



I just hope this would help someone who wants to build something compact as this one. I'm sure the size can be shrink further to somewhat a pi zero case would fit: Arduino Nano + 12v + a stepper or DC breakout.

Next I would try to drive the breakout directly from a raspberry pi - I use RPI4 and run Kstars + EKOS on it for my imaging session. If I drive the arduino focuser I need an extra USB port, which for now all the 4 USB ports are already occupied: CCD + mount + guider cam + USB thumbdrive. I also don't want to carry an extra USB hub. If I uses a ZWO camera I can make use of the USB hub on the camera body so it wouldn't be a problem but I use Atik mostly. So my next project would be feeding 12V to the RPI4 with a DC convertor (that feeds 5V3A to the RPI4 itself) and make use of the 12v to the motor and breakout so I could simply connect the motor directly to the RPI4 with the RJ11. Then develop a custom INDI focuser driver.
The following user(s) said Thank You ninosr, jnowat

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