BQ76PL455A-Q1: Looking for some help to get started on debugging and configuration.

Hello Miguel,

Thanks for choosing bq76pl455.

You can refer to the  appnotes as below link.

www.ti.com/.../universalsearch.tsp

You should take a look at-

1)SLUA791_bq76PL455A Design Recommendations

2)sluuba7a_bq76PL455EVM and GUI User Guide

3)slva617a_bq76PL455A Software Design Reference

The practical way to debug your custom board is to use our GUI.

You can use GUI by connecting a UART to USB cable(FTDI, TTL-232R-5V , USB to TTL Serial Cable).

Andy

Hi Miguel,

You should connect rx/tx/wake up/power to your board.

You can get more detaIls from EVM related app note.

Andy

Hello Andy!  Sorry for taking a day to reply.

I have looked at your repliess and the documentations you suggested.  I have also purchased a 6-pin USB to TTL Serial Cable and connected it to my custom board, but I can't seem to get the GUI working (unable to open COM port). Any suggestions for this?

I noted that the WAKE signal from the PC is inverted on the bq76PL455EVM before being directed to the bq76PL455A-Q, but I guess this is not taken care of in either the USB to Serial converter or in the GUI software?

Thanks,

Miguel

Hello Miguel,

You can download GUI software and install.

If you also have 455EVM, that will be great to make it work so that USB driver is successfully installed.

You can also check control panel of your laptop. I attach a picture for your reference.

Andy

Hello Andy!

Yes sure I had done all this. I guess I did not explain myself properly.

So, summary:

1. I do not have the evaluation module 455EVM. I am just using my custom design.

2. I did install the GUI and downloaded everything else that you refered me to.

3. I was trying to use and Arduino as a FTDI, and although it was recognized by my laptop as a Serial Communication Port (COM). Now I bought the last FTDI bridge from my local electronics store, and it is also recognized as a USB Serial Port, but the GUI is still not recognizing it. I have tried with both a 3.3V and a 5V supply

I attach some screenshots:

I also attach some of the schematics of the PCB I created. Maybe this let's you or others see if there's any problems here.

Thank you very much

Hi Miguel,

Sorry for late due to business trip.

I saw you sent a friend request.

What region are you in?

Which company are you in?

Maybe I can find local team to support you.

Andy

Hello Andy,

Thanks for your message.

I am part of a student project called Swissloop and we are based in Zurich (Switzerland). Nevertheless, I am currently in my home town in Spain for a week (which I will use for debugging), and then I will be travellling to Sweden and Latvia for another week.

Thank you for your help.

Miguel

Yep, everything was checked before and I rechecked just now. Everything is still good.

EDIT: I am continuing with other electronic debugging and I also notice that the BMS in supposedly AWAKE since the voltage in VP, V5VAO and  VDIG is 6.3V. I am assuming this is a good sign but still the COMM is not working.

On a side note, you mentioned something about local support ,would you know of someone that could help debugging this issue faster via videoconference or similar?


Thanks

Hello,

While waiting for a reply, I have tried several times to connect the board to my laptop and, I finally managed to connect it once, with the GUI setting up the number of devices and the position in daisy chain.

I will have a further look trying to identify if this problem is solved with different configurations.

Nevertheless, I still noticed some "weird" behaviours, obtaining different  and very extremes values, for the measured cells (most of which don't make sense).

I am attaching a print screen for further info. I would welcome any comments you may have.

Cheers,

Miguel

Indeed I have no idea why it happened. Tried to reproduce the same conditions and it's not working

Even more, I think the IC started frying inside (got super hot and some cracking noises) so I am not completely sure what is happening. The voltage input of the cells at the TOP pin is still around 33.5V and the output value of the VP pin is 6.8V

Thanks

It has been a while since I have heard from you Andy Li55 . Is there any chance that any other of your TI colleagues may be able to follow up my case closer, Leslie Marquez, Taylor Vogt, Roger Hwang ?

Thank you

Hello Miguel,

Sorry for delay due to being on business trip.

I will look into details and reply you by tomorrow.

Thanks!

Andy

Hello Andy,
I only connect one board, and only have one board for testing at the moment. I had 3 fully populated boards but the quality of the boards was so bad some traces came off at some point).


I will try soldering a new IC today (in less than 4 hours) and will try again. I do have 2 more spare ICs.

Where can I privately send you the schematic?

Thank you,

Miguel

Hi Miguel,

You can attach them.

Andy

OK.

There are some changes I have had to do obviously for just having 8 cells instead of the 16 cells the board is designed for.

Would you have time for a Skype call (or other like Google Hello, etc) today to go over things? I think it would greatly improve efficiency.

Thank you and let me know ASAP
BMS_Schem.rar

Hi Miguel,

I am looking through your schematic.

I will get back you later.

Thanks!

Andy

455 schematic Review.pptxHi Miguel,

I look into your schematic in detail.

Your schematic does have problem regarding Cell0/GND/Vsense0.

Please refer to the attached presentation.

Andy

Good morning Andy,

Thanks for checking it up. Meanwhile, I was able to change the IC and after a check-up, it finally works consistently (I mean, every time I connect it , the software detects the COM port and the application starts.

I still have some concerns:

-Still, the voltage sensing of the cells seems to be quite off in many of them (attached picture) and I am not sure why could this be. All cells are actually balanced and with a voltage aroun 4.18V.



-Reading more through the documentation, it is stated in one document that all GPIOs shouldn't be left floating, which I hadn't seen in other documents I had previously read. Is this true?  What would be the consequences if I'm not using any of the GPIOs.

Now, I don't like insisting but, since I will be travelling the most part of tomorrow, I would once again suggest having a call to at least start on defining my problems and revising things faster. Thank you for your understanding.

Miguel

Hi Migue,

I have given my comments and provide presentation to you.

What's result?

Andy