Hello,
Please tell me about the DIR register.
When changing the input direction
In the first communication, the direction is not changed and it is driven in the direction before the change.
It will be reflected in the second and subsequent communications.
This is not in the datasheet, is this a spec?
Hello,
This is in the datasheet. You must first right to ensure that SPI controls direction and NOT hardware pin. This is done by writing a "1" to the SPI_DIR bit. After this, you would write a "1" to DIR bit to change direction. If direction does not change, it could be that the motor is already moving in that direction. Write a "0" then to change direction. Toggle this bit and direction should change every time.
Regards,
Ryan
Hello Ryan-san,
This is Hirata from TIJ FAE.
Thanks for supporting this question.
Let me explain the situation a bit more.
First the register setting is like below.
The question is which procedure is appropriate for DRV8889(A)-Q1 when the would like to move the stepper to the different direction between #1 and #2?.
#1. DIR and STEP can be changed simultaneously like below?
#2. DIR should be changed in the first SPI command, and then STEP should be written in the 2nd SPI command like below sequence.
1st SPI command
↓
2nd SPI command
From the experiment #1 does not work well (=move the stepper to the direction of DIR=0) and we think we need to use procedure #2.
We just would like to confirm if this is right procedure for DRV8889(A)-Q1 when we would like to move the stepper in different direction.
I appreciate your support.
Regards,
Hirata
