DRV8316REVM: How to reset, 3.3VBK doesn't light up anymore

Maxime,

I'll get a response to you by the end of tomorrow.

best,

Johnny

Just ordered a new REVM board, I still have to find out what I did wrong with the first one. Looking forward your answer. I also have a DRV8305 BOOSTXL board that did not behave like this at all.

Hello Maxime,

We have not yet investigated SDO_MODE through SPI, as this device is rather new. One of my teammates plans to replicate this issue in the lab. Please let us know if you'd like us to send you a new board. In the meantime, please check for apparent shorts or open circuits via a continuity test in between AGND and the 4 SPI pins, and between AVDD and the 4 SPI pins and let me know what you find.

Best,
Johnny

Hi Johnny,

I did the checks you asked for, not short found.

AGND <-> (SDI, SDO, SCK, nCS)

3.3VBK <-> (SDI, SDO, SCK, nCS)

I would't mind a new board, since it also fried my MCU nCS pin :)

I'm willing to assist you debugging this in any way, I of course have a decent scope and logict analyser.

My  LAUNCHXL-F280049C is out for delivery.

You might want to know that this  behavior (3.3VBK led staying lit event if I power cycled VBAT) was present before I fiddled with SDO_MODE (it was in fact the reason why I fiddled with it, kinda quick trial/error thing) 

whops!

sorry, whist time I really tested with AVDD (using one side of C1), same result, no short.

I just received my LAUNCHXL, hooked up instaspin, connected correctly ("Hardware Connected").

(using https://dev.ti.com/gallery/view/InternalBLDC/DRV8316REVM_InstaSPIN_Universal_GUI/ver/1.0.0/)

The UI could identify various stuff such input current and voltage as well as Bus Voltage, but that's just the MCU's ADC working. When I click run the motor don't move.

Also, "MCU_LED" on the 8316REVM is shut down, and I tried to manually read all valid register addresses and got all 0's

I gues that confirms clinical death.

There is no sign of harm on the board whatsoever.

Hi Maxime,

Can you perform the following steps when connecting to InstaSPIN just to confirm? (not documented correctly in User's Guide)

1) After Hardware Connected, click "Enable System" on GUI

2) Wait for "OffsetCalc" box to automatically uncheck

3) Click on SPI register tab and click "Read" to read all registers. 

A good way to show whether SPI is working is if "NPOR" bit = 1 after read. MCU_LED only lights up after motor is identified. 

I am looking into the SDO_MODE issue in the lab now, will provide an update by EoD. 

Thanks,
Aaron

Hi Maxime,

Can you perform the following steps when connecting to InstaSPIN just to confirm? (not documented correctly in User's Guide)

1) After Hardware Connected, click "Enable System" on GUI

2) Wait for "OffsetCalc" box to automatically uncheck

3) Click on SPI register tab and click "Read" to read all registers. 

A good way to show whether SPI is working is if "NPOR" bit = 1 after read. MCU_LED only lights up after motor is identified. 

I just ran a test setting SDO_MODE to push pull mode, performed a functional SPI read, power cycled the device to restore defaults, and 3V3BK and VM LEDs turned off as expected. I did not see any issues where 3.3VBK LED stayed on after power cycling the board. Are you by chance connecting MCU power to 3V3BK on the DRV8316REVM, or supplying any external power besides VM to the EVM elsewhere?

Thanks,
Aaron

Weird, I can't reply to you directly.

So I did all you suggested. SPI is dead, NPOR on IC STATUS is 0, in fact everything is 0. My LA tells me this.

you can see some small spikes on MISO, but I think they're just noise.

I swear I had this weird 3.3VBK LED not shutting down from the very beginning, when connecting, precisely:

Atmel SAMD21 [GND, MOSI, MISO, SCK, SS] <-> DRV8316REVM [AGND, SDI, SDO, SCK, nCS]

as well as +12V/VGND on VBAT/PGND

**Note, I had not plugged a motor yet**

The board worked for a few hours and 15-30 power-cycles (I never got to try it with a motor). I did not have a  LAUNCHXL-F280049C at that time.

 Are you by chance connecting MCU power to 3V3BK on the DRV8316REVM, or supplying any external power besides VM to the EVM elsewhere?

No, 100% positive!

I was hooked up exactly as shown (plus maybe L-A probles)

If you're kind enough to send a replacement board, If you included a couple DRV8316 chips, I would try to rework the board to confirm that the issue was with the chip and not some other component.

Hi Maxime,

Aaron will get back to you tomorrow on this issue.

Thanks,

Matt