BQ76PL455A-Q1: Technical support on custom BQ76PL455A-Q1 system

An update after some electronic debugging and fixing some pins in the IC that were very minimally shorted, but shorted nonetheless.

I have now tried in 2 of my 4 boards, one of which is "brand new" as in, never had used before for testing, so the IC should be in original conditions, and in both I sometimes get the same error:

In other cases, I only get the error message that it's unable to find the COM port, although the FTDI is connected.

I also notice that, over time, the IC starts to get a bit hot.

I have looked through the internet and can't find any reference to this error, so any help would be welcome.

Cheers,

Miguel

Miguel,

Please refer to the attached link to get appnotes about hardware debug and software debug.

www.ti.com/.../slua791a.pdf

www.ti.com/.../slva617a.pdf

You can also find example code in TI website in bq76pl455 link.

Please also refer to schematic of EVM to double check your design.

As for connection between PC and your boards, please refer to the user guide.

www.ti.com/.../bq76pl455evm

Thanks!

Andy

Hello,

Yes. I have already tried looking through everything like you suggesested and I haven't found a solution yet =(

Maybe there are other TI experts (like Jeff F, Chuck Davenport, David Wiest Jr, Vish Nadarajah, Taylor Vogt, Roger Hwang ),that could get involved in this since we are getting sponsored by TI.

Thank you,

Miguel

Hi Miguel,

Please show me your newest schematic.

Any picture about your setup would be helpful.

By the way, I would like suggest you to get one 455EVM so that you can cross check your design.

It will also help you debug your software.

Thanks!

Andy

Hello Andy,

Absolutely, I hope everything is clear in the schematic.

I can't take any pictures of the setup, but the module is basically connected to the two battery packs in series, for each of the cells, and then the UART and voltage input  directly connected to the FTDI.

The voltage I masure from VP and V5VAO is around 5.3V, which I believe is correct and the voltage of the complete pack is around 33 V.

I had a call today with the European representative that has kindly provided the ICs for the competition and asked about this evaluation board, but this will cause more delays that we can't afford.

Thank you for your help and time.

Miguel

BMS_Schem_v2.rar

Hi Miguel,

You didn't check your design with 455EVM carefully.

You should miss connection between cell0_c and Vsense0. check 455EVM's schematic.

In your design, Vsense0 is floating.

Dear Andy,

I am sorry but I don't understand your comment.

I had a look  at the schematic and this is what I see

Let me know what's the problem.

Thank you,

Miguel

Miguel,

Now I see.

When you connect a usb cable from PC to your J UART, please make sure VIO is from PC , not VP.

For other 455 which does not communicate with PC, then you can connect VIO to its VP.

Please double check your connection between PC and 455 UART port/VIO/Wakeup.

Hello,

Yes, this is also checked and assured by a DIP switch:

Let me know

Miguel,

Then I didn't see any problem from your design.

The best way to help you out is to try to get one 455EVM and cross check your board
or Take your 455 board as stack and 455EVM board as base, let 455EVM control your board by daisy chain.


Thanks!

Andy

Miguel，

As i previously mentioned, I didn't see any problem from your design.

The best way to help you out is to try to get one 455EVM and cross check your board

or Take your 455 board as stack and 455EVM board as base, let 455EVM control your board by daisy chain.

And you may remove driver and reinstall driver again or change another laptop to connect your board by cable.

Andy