EB091 USB

[Brendan]

I'm liking this new EB091 board and choice of embedded dsPIC.

When selected as the target it all appears to be working so far - with the exception of the USB port of the target chip. Currently, when I initialise the USB through the USB Serial macro, not a blip in Windows Device Manager in response to target connect/disconnect.

Maybe I can tweak a few registers in a C-Block to configure the USB function? I'm well aware that most things USB can be a little... 'challenging', so all clues and suggestions welcome

Thanks all.

Brendan

[Benj]

Hello Brendan,

I have had USB working on the EB091 and ECIO40P16 so I will investigate why it is no longer working.

[Brendan]

Thank you Ben,
Entirely appreciated

All the best,

Brendan

[Benj]

Hello,

I can confirm that the ECIO40P16 works as expected but the EB091 currently does not. They are essentially the same chips running the same code so hopefully it shouldn't take long to track down the problem.

[Benj]

Hello,

I have tracked down the problem to a hardware fault. Basically the target dsPIC device should have it's VBUS pin connected to the USB 5V but instead it is simply connected to a 220uF capacitor. I have modified my board here and this has solved the problem and allowed the USB to fire up.

Here is a picture of my modification using insulated roadrunner wire. The right hand side of C23 is shorted to the right hand side pin on D12.

20150623_172731.jpg (53.75 KiB) Viewed 10339 times

So you can either return the board to us and we will apply the fix or you can apply the fix yourself.

I will make sure that the up coming batch of EB091 boards are corrected so USB will work straight away.

There was also a minor Flowcode definition change to alter the USB prescaler and allow it to run at the right speed.

EB091.fcdx

(45.82 KiB) Downloaded 549 times

I will explore if there are any software workarounds we can use as I know for sure I have had USB working on an unmodified EB091 earlier on in development.

[petesmart]

Hi Ben,

Any linkage to the issue that I'm having.. Is this worth a try?

Best

Pete

[Benj]

Hi Pete,

As far as I can tell this only impacts the USB peripheral from firing up. In other PIC devices the VBUS is simply connected to a cap and left but on these new devices with OTG host support you have to connect the VUSB to the 5V for device mode or provide your own 5V supply for host mode.

I think your problems are related to something else, maybe the power diodes (D7, D12) are too low current and have burnt out over time. The two chips on the EB091 are both running at 70MIPs and so this requires a fair amount of current to run. The new voltage regulator is certainly more up to the job but the diodes have remained the same as they were on the EB006.

[petesmart]

Thanks for the feedback Ben, I will run the meter over the diodes to check...

[Brendan]

Hi Ben

So you can either return the board to us and we will apply the fix or you can apply the fix yourself.

I will make sure that the up coming batch of EB091 boards are corrected so USB will work straight away.

There was also a minor Flowcode definition change to alter the USB prescaler and allow it to run at the right speed.

EB091.fcdx
(45.82 KiB) Downloaded 4 times

I've modified one of our boards and can confirm the proposed solution fully functional, complete with the new definition file
A very simple mod so we'll just mod the boards we have.


Thanks again,

Brendan