Well, I sorted out my minor problem, and the turbo is responding well... I think there may be some differences in the turbos, perhaps wiring colors are a clue as to the versions...
- My turbo doesn't time out unless there's a >75ms time between commands (I like that!)
- My turbo accepts positions from 0-1000, though there's no motion between 0 and 40 or 960 and 1000.. it balks at anything over 1000 and moves to the 0 position.
- If it loses comms, it will continue on the next command, no power cycling needed
- My turbo reacts quickly, but in a test where I had it going back and forth at full speed, it would automatically decrease it to half speed if it moved a certain distance over a certain time... I can't really test it precisely, but I have a pot on A0, and if I sweep it back and forth really fast for about 2 seconds, it'll slow down for a while and then come back.. must be an internal protection.. can't hurt!
I don't know if this is really different than the others, but it certainly means I don't have to worry about not sending a command to it in time and it going into a permanent 'limp' mode until the power is cycled... and 75ms give me LOTS of time to do the heavy math I want to do.. as well as not having to worry so much about the serial port transfer times, etc, which means I might be able to implement my "live" tuning after all.
I may start by using the Sparkfun Redboard I have (Uno or Leo based.. can't remember) and getting everything working that way, then expand and do the AFC, cruise and brake controls later.. perhaps get my own board made (Curtis, you can solder it!)
My turbo hates anything over 7~ms and defaults open
I'm going to guess they had issues with that and increased the timeout because of it... I'll try and pull as much data as I can on the exact model of it for future reference
I jumpered pin 8 (freq measure pin) to pin 3 (interrupt 1) and I'm getting a signal... I'm going to try my measurement system on it... I'm also going to abandon the curves for now since I need the inputs...
I'll have to figure out a way to precondition the tach signal.. I think it gets a 12V square wave.. perhaps a voltage divider resistor circuit coupled with a 4.5V zener and a small cap would do it