Test 1
I was testing 7.5 version with DRV 8825 first. Everything seems to work fine like @ 7.4 version
Test 2
I changed DRV8825 to DRV8834 on the board and changed DRV882x to DRV8834 in the firmware.
Power supply - 8 volts. Vref = 0.65V for my 1.4A stepper motors.
The first strange effect - stepper motors sound is heard BEFORE I run EQMOD (when I turn on the computer or plug USB). This sound takes only 1-2 seconds. Then I turn on EQMOD, another 1-2 sec. noise. Now, I have got EQMOD panel and I try to move S,E,N or W. Nothing happens. Even the RA and DEC coordinates on EQMOD window are not reacting to my pressing.
When I try to run AstroEQ Firmware Update Utility again. I've got messages: "Read Suceeded. EEPROM Blank or Corrupt!" and then "EEPROM Repaired. AstroEQ Ready for Configuration."
Test 3
DRV8834 on the board but I changed DRV8834 to DRV882x in the firmware. It "works" but motors sound very strange, louder and it seems to me the mount is slewing little slower.