• State
  • Locked Locked
  • Replies 8 replies
  • Subscribers 67 subscribers
  • Views 1572 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ51021+BQ500412: I2C data "tunnel" possible?

Benjamin Heyne
Prodigy 60 points
Other Parts Discussed in Thread: BQ51021, BQ500412

Hi there,

for my application I'd need to transfer proprietary data from the power receiver to the transmitter (uni directional). Both would be connected to a µC via I2C, so that the µC connected to the 500412 could receive the data from the µC at the 51021.

The datasheets of the parts indicate that some form of sideband communication besides the stuff needed for WPC synchronization might be possible. So...is it?

  • 0
    TI__Genius 14890 points

    Benjamin,

    This is not a simple yes / no answer.  The bq51021 can send up to 4 bytes of data as proprietary packets using registers 0xF1, 0xF2, 0xF3 and 0xF4 (refer to the datasheet for those registers).  But, it's not as simple as putting data in the registers and getting it sent.  A header needs to be added.  In this case, 0x05 (Charge Status Packet) can be used since this is not a charger.  Full details of the communication protocol are in the WPC specifications (must be a member for full details).

    The next question is how to read that data.  A standard Qi transmitter will not know what do do with this information.  

    Will your solution require a full Qi-compliant solution?

    Regards,

    Dick

  • 0
    Intellectual 970 points

    Benjamin,

    Before you do too much work on the technical aspects, it's my understanding from DLS, the EMC lab that was instrumental in getting the FCC to allow the WPC communication, that sending anything but power transfer information would not be allowed under the FCC rules.  

    Read up on it., If you want the information directly try Jack Black at dlsemc.com

  • 0 in reply to Dick Stacey
    Prodigy 60 points

    Dick,

    thanks for the answer. I don't need any compliance, it's a proprietary embedded application. So if e.g. the BQ500412 (or any other fitting transmitter part) can be programmed to accept/buffer/forward that message for access via I2C, I'll be happy.

    Best regards

    Benjamin

  • 0 in reply to Benjamin Heyne
    Prodigy 105 points

    Hi Dick,

    I have the same need of Benjamin; my purpose is to create a "communication tunnel" from receiver to transmitter.

    I don't need any certification/high performance; as you suggest, I2C is a good way for me but it's not clear what I have to do.

    Could you explain me better or suggest some documents where I will find how to send my data to the receiver via I2C and how to read them from transmitter (via I2C I suppose)?

    Thank you in advance.

    Daniele

  • 0 in reply to Benjamin Heyne
    TI__Genius 14890 points

    Benjamin,

    I do not have enough information from my side to answer this question fully at this time.  I expect to be able to amend this post late next week.

    Regards,

    Dick

  • 0 in reply to Dick Stacey
    Prodigy 105 points

    Hi Dick,

    Do you have any news?

    Thanks.

    Daniele

  • 0 in reply to Daniele Simioni
    TI__Genius 14890 points

    Daniele,

    Unfortunately, not yet.  This is not something that is documented - as it was not part of the original intent.  We are having internal discussions on how best to roll this out.

    Regards,

    Dick

  • 0 in reply to Dick Stacey
    Prodigy 60 points

    Dick,
    sounds great - can you give an indication of when you could do that? Any chance to get the information prior to that date (maybe covered by a NDA or similar)?

    Best regards
    Benjamin