The first version is made with a junk 18650 power bank, I've to remove the original USB socket and the charging circuit so as to accommodate the buttons. Once the 18650 ran out of charge, I have to pull it out for recharge which is inconvenient.
Later I found that there is a dual 18650 version available at very cheap price without battery, so I ordered them and carry on the modification. The idea is to keep the power bank circuit and I will only use a single 18650, so the space left could be used for the buttons.
Once the 18650 ran out of juice, I can recharge it with a standard USB cable. This controller could serve as a emergency power bank as well.
The whole thing costs less than $3 USD, most of the parts were recycled parts.
Tonight, when I was clearing up my messy equipment cabinet, I found that I have a motorized DEC for my Sky Adventurer and it requires a socket to control. I used to have another controller for it, but why not consolidate them as one?
Here we go, it only means some more drilling, fitting and soldering work.
So, let's test it with the DEC motor of the Sky Adventurer:
And then go back to the focuser of my NGF for my Ranger:
I even tested to use this controller for its original purpose, i.e. a power bank.... and it works flawlessly despite it only has a single 18650 rather than two. The blue LED lit up for this mode. On charging from the micro USB, the red LED lit up as it should be.
Very nice one, way better than my original one. More powerful, compact and more beautiful.