body:
You can see below the NEQ3-2 mount transformed into alt-azimuth operating mode
Here the raspi2 with the astrokit shield above.
it is seen that electronics is minimized with only a supply adaptation thanks to voltage regulators dual H-bridge 1A and the infrared LED
All other features are manage by the embedded software to sum up :
- microstepping mode with PWM chopper modulation to have the best motor control function with smooth movement (until 1/1000 depending on CPU works)
- calculating the azimuthal speed is refreshed regularly so that motion follows a curve, not a straight
- ability to track objects catalogs but also the planets moon and sun which require more calculations
- the linux kernel is patched soft real time so that it allows the scheduler to average latencies of the system which is sufficient for long pose photography
- it is also possible to use astrokit to drive an equatorial mount very simply
This is the last proto =>
And the final card with a minimalist electronics =>
The imperfections and delay in the vertical motion of the video are due to gear lash on NEQ3-2 DEC
A long pose on EQ-MODE (about one hour) showing that system accuracy is better than EP from VIXEN GP (wich is about 30" arcsec)
The circle-shaped tracking is normal and due to the rotation of the DEC error vector,
due to the difference between the north pole-object circle radius and mount axis-object circle radius
you may notice than EP forms a periodic curve with 10 minutes period =>
