View Single Post
  #76  
Old 22-03-2011, 10:10 AM
alistairsam's Avatar
alistairsam
Registered User

alistairsam is offline
 
Join Date: Nov 2009
Location: Box Hill North, Vic
Posts: 1,838
Quote:
Originally Posted by hikerbob View Post
alistairsam I'm thinking of focusser control. If I'm understanding it right the 223 could be instructed to drive the focusser in to a stall (fully in) to establish it's position and then could position the focusser exactly at a nominated point. Perhaps temp compensation could be built in as well as focus points for camera and different eyepieces.

Bob
Hi Bob,

I don't think you need to use stall detection for this although its a good application. you could easily use a limit switch to indicate when the focuser has reached the end of the tube. the mcu can poll that switch or
you could have a simple optical limit switch as well which can raise an interrupt to the mcu.

so on power up, the stepper rotates in one direction until an interrupt is raised, when it stops and sets the step counter to zero.
and then depending on what switch you press, it could go to a preset step number that could be the position of different eyepieces or cameras.

i'll be building this soon as well.
Reply With Quote