• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 63 subscribers
  • Views 418 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

Original question:

BQ79616: Require Example code for communicating one BMS chip with MCU via UART

BQ79616: UART Communication

Joseph Morse
Prodigy 10 points
Part Number: BQ79616
Other Parts Discussed in Thread: USB2ANY

Attempting to communicate with a BQ79616 development board over uart from a micro. Having issues getting the chip to respond.

  • I have successfully woken up the chip with LED D1 illuminating.
  • I have not been able to get a single UART message to transmit from the chip.
    • I thought this might be a voltage signaling issue; rather than going direct to the RX/TX pins through J3 I now have the isolator chip powered from the UC dev board and the BQ is receiving 5V UART signaling. (The datasheet doesn’t specify; is this required? Or will the BQ chip work off 3.3V signaling on the UART?)
    • UART waveform verified on oscilloscope; timing and data appeared correct.
    • CRC has been verified as being calculated correctly.
    • In an attempt to isolate whether this was an RX or TX issue I sent a message to turn on TSREF; message verified on oscilloscope (at BQ test point post iso-transceiver) as valid..... nothing.

Is there something that I am missing in getting this to communicate as a single device?

  • 0
    TI__Expert 3760 points

    Hi,

    The 3.3V might work but the 616 UART is designed to work on a 5V UART. I may be able to replicate this if I am able to get a bit more information: 

    1. Could you confirm that you are using a microcontroller directly connected to the 616? Also, which microcontroller are you using? 

    2. Can you send a picture of the way the EVM is configured? I want to double check that the hardware configuration is correct + replicate this setup. 

    3.  Are you able to communicate with the device EVM when communicating directly to the PC+GUI? If you use a USB2ANY to connect the 616 to the laptop are you able to communicate?

    4. Can you send an oscilloscope capture of a command? 

    Please let me know. 

    Thanks,

    Nancy

  • 0 in reply to Nancy Hidalgo
    Prodigy 10 points

    1.) It is no longer directly connected. After assuming the BQ wasn't expecting 3.3V signaling I started connecting through the isolator/level shifter on the evaluation board. The micro I am using an STM32; F446RE to be exact. 

    2.) I unfortunately cannot send a picture currently; out of the office for a few days. From memory. J1 OPEN, J2 CLOSED, J18 CLOSED, J21 CLOSED, J14 CLOSED. 11.5V supply connected to PWR and CELL0. J16 and J14 set to datasheet requirements for simulated cells. I am assuming that the chip is getting powered OK as I am able able to wake the chip.

    3.) I have not tried to connect to PC; I figured why spend the money on another adapter when the chip talks UART. 

    4.) I will try this on Monday.

    I also will probably buy the adapter. Can you please provide a link to the desktop software tools?

  • 0
    TI__Expert 3760 points

    Hi,

    Thanks for the additional information. Here is the link to request access to the folder with the GUI download: https://www.ti.com/licreg/docs/swlicexportcontrol.tsp?form_id=305269&prod_no=BQ7x61x-Q1_DEVELOPMENT&ref_url=app_bms_bms-bap

    Let's revisit on Monday. 

    Best,

    Nancy

  • 0 in reply to Nancy Hidalgo
    Prodigy 10 points

    I got data on the TX pins; you guys really should update the datasheet for the development board. Stating 9V is misleading; even though it suggests 18V. I was supplying 11.9V as this was a safe voltage for both boards. Since CVDD was rock solid at 5V and I was able to wake the chip I had assumed that this was adequate power. I switched over to a dual output supply and gave the BQ board 25 volts. BQ chip is now sharing its secrets.