MCF8316A: No output from DACOUT1/2 for real time monitoring

Julian Chu

Prodigy 50 points

Part Number: MCF8316A

Hi,

I tried to measure IPD angle through "Real time variable tracking" while motor is spinning.

I use software to set Pin36 as DACOUT1, and hook probe on "X1", but I don't see any signal on oscilloscope.

I also don't see correct VM voltage if I select DACOUT1 as VM.

Please provide suggestions.

Thanks,

Julian

over 3 years ago

0 Eric Chen over 3 years ago

TI__Genius 9220 points

Hi Julian,

I believe the DACOUT1/X1 signal is actually on PIN37. Could you please try probing PIN37 for DACOUT1 instead?

Below are the correct pin function mappings on PIN36, PIN37, and PIN38:

This is a known issue in the device register map, and will be fixed in the next datasheet and GUI release.

Sorry for the confusions.

Regards,
Eric C.

0 Julian Chu over 3 years ago in reply to Eric Chen

Prodigy 50 points

Hi Eric,

It seems to me the test yesterday that I probe "X1" was correct. "X1" is connect to PIN37.

Below three point is short.

If I toggle "DACOUT1" Polarity from UI, I can see Pin37 voltage change. But other signal such as IPD angle not working.

Please check.

Thanks,

Julian

0 Matt Hein over 3 years ago in reply to Julian Chu

TI__Mastermind 21805 points

Hi Julian,

Eric will get back to you tomorrow!

Thanks,

Matt

0 Eric Chen over 3 years ago

TI__Genius 9220 points

Hi Julian,

What voltage do you see when measuring IPD Angle?

Please ensure IPD is configured and enabled
IPD Angle is determined each time motor starts up and will only update when IPD completes successfully.
Under the Motor Status side panel, could you please expand the Algorithm Variable Status Select dropdown and check IPD Angle. Please check to see if IPD Angle is updated here in the GUI each time IPD is run during motor startup. (make sure to enable the "Auto Read Motor Status toggle" button)

Thanks & Regards,
Eric C.

0 Julian Chu over 3 years ago in reply to Eric Chen

Prodigy 50 points

Hi Eric,

1. 5.2V

2&3.

The question is I cannot see any real time signal from X1 or X2. Here is my configuration:

Even I select to monitor "VM Voltage", I still not seeing voltage variation, X1 output always stay at 1.5V.

It seems to me I may miss something important.

Thanks,

Julian

0 Matt Hein over 3 years ago in reply to Julian Chu

TI__Mastermind 21805 points

Hi Julian,

We will get back to you tomorrow on this!

Thanks,

Matt

+1 Eric Chen over 3 years ago in reply to Julian Chu

TI__Genius 9220 points

Hi Julian,

I found a bug in the GUI where the variable address aren't updated when selecting the variable category. To workaround the issue, after changing the DACOUTx variable category dropdown, please change the DACOUTx variable select dropdown menu to a different value, then back to the desired variable. Make sure that the DACOUTx variable address field is updated accordingly.

I've fixed this bug and published the new MCF8316A_GUI v1.0.1 here. You'll need to download and reinstall if using the offline version.

Alternatively, you can also look up the address hex value in the GUI's register map view, then input the hex value into the DACOUTx variable address field manually.