regarding the DRV8829 EVM code for indexer mode operation on board

Hi Raju,

I remembered the using of DRV8829EVM with GUI in the external index mode (with the help of the MCU on the EVM) was very smooth if you followed the EVM User's Guide step by step.
Note that DRV8828/29 don't have on-chip index mode.

www.ti.com/.../slmu002.pdf

Best regards,

Hi Wilson Zuo,
I have studied the user guide of the evm but not getting what changes have to be made in the code and on the EVM board in order to work in the indexer mode and which are those indexer mode pins on the board

Hi Wilson Zuo,
I got to know that DRV8829 EVM has an external index mode operation through J10 and J11 connectors but how we can send the controls in order to move the stepper, I mean in which way we can send the controls to the j10 and J 11 so that the stepper motor could move, as I have also tried to debug the code in CCS by giving breakpoints but it is not at all hitting the breakpoints, and also when I change the mode from serial to parallel using DIP switch the status LED is also not blinking, please tel me how and what I need to do

Hi Raju,

Sorry for my late response. So you want to use the MCU index mode. According to the User Guide, we should set S1:7 = HI and S1:8 = HI, to let the MCU working at index mode and taking external STEP / DIR from J10.

So you can running the motor with GUI in serial mode without issue, right? Please make sure this is fine to rule out any other issue first then change the mode to use external singal.

Best regard,

Hi Wilson Zuo,

Motor is running with GUI in serial mode without any issue, but as you said I changed the dip switch S1:7 and S1:8 pins as HI and took an external supply signal of 3.3v to the step, dir but the motor is not running what I need to do, and how I can run the motor with my application required controls using the indexer mode.

As in my project I need to control the Door operation i.e., open and close using the stepper motor by giving controls using a Push button switch\any of the switch, as I press the switch the door should open and wait for some time again it should close. Please help me for this

Hi Raju,

Pulses are required on the STEP input (0 to 3.3V) to advance the motor. If you are connecting a static 3.3V supply the motor will advance 1 step and remain at that point until the next low to high transition on the STEP pin.

If the motor does not run after providing pulses to the STEP input, please capture the state of the pins on header J10 and J11.

Hi Rick Duncan,

Even if I apply the static input motor is not moving for the 1 step also, I am not getting what is the problem, and in which way we can apply the pulse input of the range 0 to 3.3v?

Is that I need to capture the state of the header J10 and J11 in the CRO?

And please tel me how we can move the motor in different steps?

Hi Rick Duncan,

I am looking forward to hearing from you regarding the above issue, How I need to apply the pulses to step and dir pins of the J10 connector, I am trying to trigger the pulses from the timers in the code is that correct way to apply pulses to the particular pins of J10, I am unable to operate in indexer mode help me in this issue.

Hi Raju,


Please set SW1:7 to high and SW1:8 to high.
Next reset the MCU by either pressing the reset switch S2 or cycling power
At this point the device should be ready to operate using the inputs on J10 and J11.

To operate, place
1) a logic low on RESET INDEX
2) a logic high on DIR, USM2, USM1, and USM0 -- these can be changed later
3) a logic high on nSLEEP and nRESET -- you should see current consumption increase by a few mA
4) a logic high on ENABLE STEPPER -- you should see current consumption increase by many mA
5) a series of pulse on STEP

To change direction set the DIR in in the opposite state. To change microsteps adjust USM2, USM1, and USM0 as desired.

Please confirm that you see the current changes at steps 3 and 4. If you do, step 5 should work.

Rick Duncan,

We are facing the issue of motor stalling.

Scenario 1:

EVB board set to operate in Serial mode.Motor set to operate in Full step,

Observed that the motor rotates initially for few seconds and the motor gets stalled.

We see that one of the motor driver U3(DRV 8829) is heating more compared driver U2.

Please provide any inputs regarding this.

Scenario 2
We observed for other stepping scenario like half,quad,1/8,1/16 and 1/32

We did not observe any stalling in this cases.

Clarification 1:

Please provide the initial setup of GUI  that needs to be done for proper operation in serial mode.

please provide any snap shots for the same.

Clarification 2:

Is it mandatory to set the I0 to I4  of both the phases or it can be left unchecked.

Clarification 3:

Currently we are operating Driver IC (DRV 8829)with 12 V/5A adapter.

Is it we need to operate from only the Battery?

Hi Raju,

Scenario 1:

EVB board set to operate in Serial mode.Motor set to operate in Full step,

Observed that the motor rotates initially for few seconds and the motor gets stalled.

We see that one of the motor driver U3(DRV 8829) is heating more compared driver U2.

Please provide any inputs regarding this.

Scenario 2
We observed for other stepping scenario like half,quad,1/8,1/16 and 1/32

We did not observe any stalling in this cases.

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I am assuming you are using the same acceleration profile and step rate (pps) for all step sizes. Is that correct.

If so, you are probably running the motor to fast at full step. If you double the step rate (pps) at half step, 4x it at 1/4 step, etc. you will probably see similar stalls.
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Clarification 1:

Please provide the initial setup of GUI that needs to be done for proper operation in serial mode.

please provide any snap shots for the same.
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This depends on many factors, such as the system voltage, the motor specifications, the load on the motor, and the decay mode. That is why the GUI has the various settings.

The motor manufacturer can provide speed vs torque so you can limit the acceleration and final speed.
A Current probe helps visualize how the motor is responding which allows tweaks to the GUI.
If a current probe is not available, the voltage across the sense resistor can be measure to help visualize the current. Using a math function can potentially convert the voltage into current.
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Clarification 2:

Is it mandatory to set the I0 to I4 of both the phases or it can be left unchecked.
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It appears to be required to set them. You should set the I4:0 on both A and B with similar values, and set the VREFA and VREFB with similar values.
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Clarification 3:

Currently we are operating Driver IC (DRV 8829)with 12 V/5A adapter.

Is it we need to operate from only the Battery?

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This depends on the motor specifications. If the full scale current in the motor is less than 4A (20% margin), it should work.
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Can you provide the motor specifications, model #, resistance, inductance, current rating? There may be other devices such as the DRV8711 with external FETs or the DRV8880 with internal FETs that make system integration much easier. There is a booster pack for the DRV8711 and an EVM of the DRV8880.