G'day Paul,
It was me that David was talking about. It was late last year he sent me the "special cable" he made up, but since receiving it then I've had too much on my plate (work and having a baby) that I hadn't had time (when there was the very rare clear night) to play with it.
Bit of background, which he may or may not have explained to you, but I'll repeat here for others. The MHP does have a built-in focus controller with DB9 serial connection. The FeatherTouch focus motor that I have (MSM30) takes a RJ11. I posted back then
here on IIS trying to figure out the pinouts to make up my own cable to connect the 2, but didn't have much luck. I was in contact with both David from HitecAstro and also Wayne from Starlight Instruments to figure it out. Eventually I did get the info I was after, and did make up my own cable. Still didn't work, and realised that the MHP focus controller is 12V, but the FT motor is 5V (if I remember correctly). It took a while to figure this out because I couldn't find any specs on the FT that told me what motor was in it. Eventually I figured it out. Perhaps understandably, Wayne from SI wasn't forthcoming with the inner workings of his gear for proprietary reasons. I mean, he sells his own focus controllers so why give info freely to competitors.
Talking to Dave, and also Geoff (ozstonomer) and Peter (peter_4059) from IIS, we worked out that if we put resistors in the cable between the two, we could drop the voltage and it should work. Dave was extremely helpful, and made up the cable with a box of resistors to get the voltage right. Only downside is the resistors get hot in the process, but from my testing it's not an issue in the box, and after all once you've got focus you're not using the motor much.
Anyway, last night I finally had a play with it. It certainly does work with the MHP software's focus controls. Where I had some issues was with MaximDL's focus control. I chose the MHP ASCOM focus controller in MaximDL's setup, and it seemed to work sometimes, but not others. Bit unpredictable. Sometimes the motor would work, others not.
I couldn't get to the bottom of where the issue was last night, will have to muck around with some more testing. And I'll eventually be using FocusMax but haven't tried that yet. I may be a driver issue or something.
But it certainly worked reliably with the MHP software focus controls.
Hope that helps. I'm going to let David know these results too, as I haven't been able to give him feedback yet.