Hi,
For research sake and the will to help others with the jumping/missing steps problem, I decided to try the diode trick.
The good news is that it really worked!
As you can see in the pictures the circuit I made for the diodes was to simply solder their leads together in a loop, leaving
an overlap of about 7mm on each side for connection. Sorta looks like rabbit ears when connected to each phase of the motor.
Something much more elegant can be made using a project circuit board or somehow integrate the diodes in the AEQ circuit.
(Please ignore the resistors on the left side of the breadboard. They are from another project)
Although I used an Aduino Uno, a different motor and a different code for this test, the missing steps were still there at 1/32 microstepping.
After connecting the diodes the problem dissapeared but the sound coming from the stepper motor was similar. It ran smoothly but I didn't notice any difference
from the fast decay PIN 19 to PIN M2 soldering modification.
I was using 1N5408 diodes which have maximun continuous forward current rating of 3A. After having the motor running for about 40 minutes they never got hot not
even warm. The Supplied power to the DRV8825 was 12v - 2A and the Vref for the 2.6v and 1.2A rated Nema 17 stepper motor was 0.59v.
Although I have adjusted the worm and worm gear to be quite tight I have problems with phd calibration due to backlash. Star goes north but doesn't come back to its place.
I wouldn't worry so much about the mount not going back south during the PHD calibration. Mine also does that and the guiding is excellent anyways. This glitch
also used to happen when my CG5 was stock. Maybe is a software problem.
In guiding I still have similar problems of overcorrection on both sides.
Like Tom mentioned, guiding problems like overcorrection can be atenuated in EQMODs "ASCOM PulseGuide Settings" as well as "ASCOM PulseGuide Monitor".
Further information on how to use these settings can be found at the EQMODs website.
If you still haven't set the DRV8825s into fast decay mode or done the diode trick, I'm afraid that your guiding problems are related to the mix decay problems these drivers have.
Hope all these helps
Alex