WiFI Version with Moonlite protocol now available just look at my other designs to find it.
OK so here is my bluetooth remote focus control for the skywatcher for under £20 ($30) which is 'marginally' cheaper than similar commercial offerings.......
Bear with me while I tweak various files for upload.
All the electronics are off the shelf arduino modules so the only soldering is the connections (although mine is put together with Dupont connections as its a prototype)
Parts List (in GBP) all electronic parts from Gearbest in China
2 push button switches (mine are mounted on a piece of veroboard fitted behind the top cover (these are not essential but I found having manual controls is useful when viewing rather than imaging) - haven't drawn this yet so its next to do.
HC - 05 Bluetooth Serial Module (Gearbest £2.52)
LM2596S Step-down Module (Gearbest 69p)
ULN2003 Motor Drive Board Module (Gearbest 45p)
KEYES 28BYJ - 48 DIY 5V Stepper Motor (Gearbest £1.53)
High Performance DIY Nano V3.0 Atmel Atmega328P (Gearbest £3.29)
Wire to join up the bits (connection diagram included as a PDF in the files)
Some m3 capped screws of various lengths, a few nuts and a length of GT2 belt (exact length will depend on the final print & motor position. I cut mine and superglued it as not too much load)
Two M3.5 X20 screws to replace the two removed focuser screws
Power input is 12VDC so can be run off a DC psu or car battery (LM2596S module has to be set for 5V output before connecting it up as all the internals run at no more than 5V)
Read the last sentence again it is VERY important.
The 3 printed items should be done at >50% infill.
A number of libraries are required, these are defined in the Arduino file.
The mobile phone app is Android only since the iPhone won't recognise the HC-05 module. Though you can open a bluetooth serial port on a computer and send command "M" and the focuser will respond with a menu for controlling.
Marked as work in progress but it is working and I have tested it - in progress because I need to finish writing it up -
Operating Instructions to follow
Setup procedure to follow