I have just purchased a SkyWatcher StarAdventurer 2i to enhance my astrophotography. I already have a remote timer and, of course, the K-70 has lots of timer options built in which I had intended to use.. However the StarAdventurer can control the camera plus the camera/StarAdventurer combination can then be controlled from an App over WiFi.
Whilst owners of Canon, Nikon and Sony etc. are generally well catered for by device manufacturers, Skywatcher appear to have forgotten us Pentax owners. Therefore there is no connect cable available for Pentax.
I did a bit of research, looking at the wiring diagrams for Canon cameras and Pentax cameras. I realised that the early Canon cameras had effectively the same signals on the tip, ring and sleeve of the remote plug. Ok so the Pentax is actually tip, ring, ring, sleeve but the Internet advice is that the sleeve and adjacent ring should be shorted together making them one for the correct operation of the Pentax shutter anyway.
Therefore the only difference is that the Canon is a 2.5mm plug and the Pentax is a 3.5mm plug. I purchased the Skywatcher Canon R1C Cable and a 2.5mm to 3.5mm stereo adaptor (Stereo because it naturally shorts together the sleeve and adjacent ring) and IT WORKS! I now have a Skywatcher StarAdventurer controlling a Pentax camera!
I should add that in the settings menu on the camera you need to manually set the input port to Remote Control as it does not auto-detect with this cable.
Posting this here for future reference for someone. I