Part Number: DRV8889-Q1
Dear TI Team,
I have an issue with the SPI communication of the DRV8889 stepper motor driver. Maybe ist similar to the post https://e2e.ti.com/support/motor-drivers-group/motor-drivers/f/motor-drivers-forum/1504181/drv8889-q1-spi_error?tisearch=e2e-sitesearch&keymatch=DRV8889%20spi_error#, but i could not find the issue.
Here is an actual scope of the DRV8889 response, and one can see on the MISO, that FAULT and SPI_ERROR is issued. This is the first access after NSLEEP was activated. The DRV8889 accepts the SPI commands without issues, but we would like to have no errors.
BR,
Wolfgang
Part Number: DRV8889-Q1
Dear TI Team,
if we use the driver in fullstep mode (0000 or 0001), we see heavy step losses with our motor. Its occurs under different speed conditions, alos very slow. The orange line is recorded with 1/2 step mode, the blue with full step 70% mode. All other parameters are the same.
Any ideas whats causes this behauviour?
BR,
Wolfgang
Part Number: DRV8889-Q1
Tool/software:
Thank you for your help.
There have been three cases where circuits using the DRV8889-Q1 suddenly stopped working. The cause of these cases was a failure of the DRV8889-Q1. No output was obtained when commands were sent to the DRV8889 via SPI communication. Since it has been working fine up until now, we believe there is no problem with the communication process.
I am having trouble figuring out why the IC broke.
If there have been similar cases in the past, please let me know the cause and countermeasures.
(This text is written using Google Translate)
Part Number: DRV8889-Q1
Tool/software:
Hello everybody,
I want to drive the motor driver at Full Scale Current of 1,5A, so the VREF needs to be 3,3V and TRQ_DAC = 100% (according to formula on page 20).
In section "absolute maximum ratings" is written the pin can be driven with Vmax = 5,75V, but in Datasheet in table "Pin Fuctions" on page 4 is written that you can connect a maximum of 3,3V.
I will connect the pin with a voltage divider and to have the IFS = 1,5A the voltage is slightly higher as 3,3V (about 3,5V) to reach maximum current.
So the question is, if this is acceptable?
Best regards,
Alex
Hi Songhao,
Thanks for your post.
SPI is currently set to mode 1, that is, CPOL is 0, CPHA is 1, what is the communication frequency range of SPI?
As per datasheet it can be up to 10 MHz SCLK. Typically applications use 1 or 2 MHz SCLK to minimize effects due to stray capacitances and glitches.
The measurement of the FAULT foot has always been low level, may I ask whether the foot has always been low level can be eliminated through software control?
Are you referring to the nFAULT pin being active LOW? Please elaborate the use case.
After the gui_loop is initialized, it enters the GUI_loop. If it is not possible to wake up the chip by gui_loop, what should I do
Sorry we do not understand what gui_loop means please explain? Did you mean the EVM-GUI app program? Which chip needs to wake up? Thank you.
Regards, Murugavel
Part Number: DRV8889-Q1
Hi TI Team
We currently have waveforms for two different phenomena occurring during startup. Are these two phenomena normal? Could you please provide your diagnostic tools and explain their causes?
Figure 1: In what we consider a normal machine, during startup, before the EN pin is pulled low, there is a brief fault signal of approximately 170µs.
Figure 2: In what we consider an abnormal machine, there is a brief fault signal of approximately 6ms.
fig1:
fig2:
Part Number: DRV8889-Q1
Tool/software:
[Question]
For Open Load detection.
Is it possible that nFAULT pin does not indicate the error(Low) while there is Step signal if Motor is set to Open?
Fault is only detected if there is no Step signal?
Part Number: DRV8889-Q1
Tool/software:
Hi Murugavel,
The thread "DRV8889-Q1: DRV8889-Q1 stall detection issue" has been locked. Sorry for opening this thread for response.
We got 14HK0407N stepper this week, and the good news is we could detect stall based on this 14HK0407N stepper.
We might choose other motors in other projects. Another question is: For stall detection, is there any recommended standard for motor selection? Phase resistance<10ohm, Phase inductance<10mH?
Thanks,
Alex
Part Number: DRV8889-Q1
Ref Section :7.5 Programming
The SDI input data word is 16 bits long including R/W, Address and 8 bit data. If the data word sent to SDI pin is less than 16 bits or more than 16 bits, a frame error occurs and the data word is ignored.
There are 8 control register availalbe in Drv8889 device, if we need to configurate 8 Control register supposed to send 8 frame. which is impacting system startup time if need to use morethan 1 driver.
So my question, is it possible to all 8 control register value with in single frame?
Part Number: DRV8889-Q1
Hi team,
There is a question about DRV8889A-Q1, nSCS pin is internal pullup to DVDD(current source), usually Serial chip select signal is 3.3V, but DVDD is 5V, is there any problem?
I see that the voltage range we support includes 3.3V. Does that mean we can support it if customers use a 3.3V SPI connection without any design changes? Don't you need to add a level shifter?
