MCF8316AEVM: i2c communications stopped working

Hi David,

Can you verify Jumpers are proper? Please verify FG, nFault line level also?

Also, I recommend updating for Motor Studio GUI, please follow this link to update to Motor studio 

(+) [FAQ] Motor Studio GUI - EVM Firmware Compatibility - Motor drivers forum - Motor drivers - TI E2E support forums

You can download latest motor studio available to download.

Another question is, what is the part number used on the EVM? Is this MCF8316A or MCF8316C? Motor studio can find the device type automatically.

Thanks and Best regards

Venkatadri S

FG and nFAULT are both at +3.3V.  This is a MCF8316A.

What would cause the i2c clock line to not toggle at all?

Tried to update the firmware on the EVM.  I have a MSP430 Launchpad, but apparently not the right one.  It doesn't look like the one in the picture and I can't find any pins labeled "SBWTDIO" or "SBWTCK".  Why would you have multiple products all called "MSP430 Launchpad"?  New, unique names are free.

The Launchpad I have is MSP-EXP430G2.  After looking through the user manual, pin TEST is the same as SBWTCK and RST is SBWTDIO.  However, this doesn't work either.  When I press the "load image" button on the Unitool, I get "target device not found or not supported".

Hi David,

Whether MSP-EXP430G2 is detected by Uniflash at the beginning?

Can you post image of the connections?

How are you powering the EVM?

Thanks and Best regards

Venkatadri S

Hi Venkatadri,

The MSP-EXP430G2 is NOT detected by Uniflash.  I select it from the list.  It does appear in Device Manger as a virtual comport:

I am powering the EVM by wire connections to the MSP-EXP430G2.

I am trying to send a picture of the wiring, but the "insert" function here is telling me I am not allowed to.  Screen shot and paste doesn't work either.  I was able to insert the screen shot above of Device Manager.  ????

Thanks,

Dave G.

Hi David,

Uniflash support MSP-EXP430G2 

 I also wanted to suggest for MCF8316C instead of MCF8316A.

Please see below table for quick production difference

Thanks and Best regards

Venkatadri S

I'm still dead in the water here.

1.  I can't migrate to the MCF8316C until I get the EVM working.  I can't program the firmware.  What does it mean that the MSP-EXP430G2 is NOT detected automatically by Uniflash?  That should be a big clue, but I don't know what that means.  How do I troubleshoot what is wrong?  What should I see in Device Manager?  How do I know if the correct driver is installed?

2.  There is some other underlying problem.  IF I TRY "FIND ADDRESS", AN OSCILLOSCOPE SHOWS THE I2C CLOCK NEVER TOGGLES!  The GUI goes through the motions, the addresses count up, but the i2c clock stays high the whole time.  This is also a big clue.  What are possible causes?

Thanks,

Dave Gustavson

Hi Dave,

We will discuss about 1st question later. I want to continue debugging for the 2nd question.

Well, I wanted to provide latest device and GUI options and hence suggested to update the EVM firmware.

Unfortunately, you are not able to connect the programmer tool as well.

Device manager able to detect the com port but not able to show TI MSP USB in the USB connections?

For the second question, are you using the old GUI or MOTOR STUDIO?

Is D6 is blinking with old GUI?

When you power the EVM what is the DC bus current board is consuming?

Can you show image / photo of the setup?

Thanks and Best regards

Venkatadri S

Hi Venkatadri,

Attached is a composite screenshot of Device Manger.  On the left is with the LaunchPad plugged in, on the right is without.  It shows up as a virtual comport and under USB controllers as a USB Composite Device, shot of VID/PID shown.  Is this how it should be?

Picture of connections between Launchpad and EVM:

Not sure about the supply current questions.  If I check the +3.3V line between the Launchpad and the EVM, it shows 9mA.  If I apply power to the VBAT connection of the EVM, no motor connected, it draws 30mA.

Thanks,

Dave Gustavson

I got a new EVM and that is working OK so far.  However, the whole reason I went down this rabbit hole is because I am having EMI issues with my existing design and I wanted to try slowing down the fet switching slew rate.  Using Motor Studio, when I try to set the slew rate, I get this:

Why are the slower slew rates blocked???

Hi Dave,

About slew rates, yes only two are supported and other slew rates are removed because of lower efficiency loss.

Is 125 V/us not helping?

Did you enable SSM?

What spectrum EMI is failing? Class level?

What is the PWM switching frequency?

Just for your information, the new product MCF8316D/MCF8315D supports PWM dithering.

The dithering can be configured and able to spread the energy near to the center switching frequency.

About the debug interface, Uniflash should prompt required software.

When you plug the launchpad device manager should detect two ports like below 

Can you try installing LaunchPad, FET430UIF from TI.COM and test again.

Thanks and Best regards

Venkatadri S

Hi Venkatadri,

Yes, I understand slower slew rates will decrease efficiency, but not meeting EMI is a showstopper.  The noise is very broadband, around 150 to 300MHz.  PWM frequency is 50KHz.  We are trying to meet FCC-B.  Yes, SSM is enabled.

If I manually edit the .json file, can I try the lower slew rates?

Thanks,

Dave Gustavson

Hi Dave,

We want to disable lower slew rate for other reasons and hence we removed the configurations.

I recommend MCF8316D/15D and use PWM dithering feature to improve the EMI.

Thanks and Best regards

Venkatadri S