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Understanding L9942 Stepper Motor Driver

Question asked by Siva Murugesan on May 8, 2015
Latest reply on May 18, 2015 by Siva Murugesan
Dear All,

Thank You for your great support as always..

I have the following clarifications,
  1. Tried to set STALL threshold using the AN2650 procedure, when the STALL threshold value is 00000000 STALL is not set, but when the value is 00000001 the STALL is set. For just a time period of 16us the stall is set.  The frequency of STEP input was 400 HZ and Full-Stepping mode was used. So, is there any other parameter which has to be taken care for proper stall threshold?
  3. Does stall threshold value setting should also consider the STEP input frequency?
  5. For change in STEP input frequency, the motor is not smooth and stops rotating. What is the reason for this? For Full-stepping, the motor is smooth only from 380 to 420 Hz and Micro-stepping does only when there is more than 1 KHz. When referred to the datasheet for STEP input details, only the minimum time period required is given. Is there anything else which should be taken care of?
  7. What is the proper way to stop the motor? Is disabling the EN (Enable Input) is the only way?
  9. Phase A and Phase B open error is always there even when the motor is operating smooth? The same error is not there when a different motor is used (different specification all together). What could be the reason?
  11. How to choose an appropriate decay mode for a stepper motor?
Thanks in advance