Stepper motors etc.

Howdy again.

Due to numerous requests (=1) I have decided to change the language of this blog to english.

Ok, the status of the project is:

Software, done:

• i2c master-slave messaging is working properly. Needs proper messaging to be defined though.
  
• Stepper motor control is finetuned
• "Calibration" (setup) of stepper motor driven pointer is coded
• Functions driving pointer to point desired value have been written. And it works. Almost.
  
• Reading of one rotary encoder works ok
  

Software, next:

• Control functions for servos (3)
• Add another rotary encoder reading
• Start coding ethernet - i2c "bridge"
  

Hardware,next:

• Still looking for cheap stepper motor with very fine steps (more than 100/revolution)
• Get one of these for ethernet-i2c-board
• Figure out the stepper motor current limiter system
• How to find the "home" position of pointers? Hall-effect sensors or optical interruptors or perhaps something else?
  

Mechanics, considerations:

• Print gauge backgrounds, buy one Simkits kit (comes with tens of backgrounds) or buy real instruments from boneyard?
• Use real instrument casings or buy 3" plastic pipe from hardware store?

For stepper motor consideration, here is my current selection of motors.
From left:

• STH-39D191, assumed to be 1.8degrees version. Othervise very nice but quite big.
• PF35T-48L4, about 48 steps per revolution. Makes pointer movement very choppy. Cheap and big.
• QH4-4205 from old printer. Very small, makes motor control IC _very_ hot, needs current limiter reconfiguration. Very small = could put three of these to, for example, altimeter.
• Background: Expert SL300-servo for VOR and ILS.
• Tomorrow I will go to local Fry's electronics and buy one 3.5" floppy to see if it has a stepper motor in it. $4.99.