BQ79631-Q1: BQ79631-Q1通信建立

Part Number: BQ79631-Q1
Other Parts Discussed in Thread: BQ79616-Q1, ISO7742, BQ79616

BQ79631-Q1通信建立问题!

1.使用串口通信对BQ79631-Q1唤醒成功(1M速率),进入ACTIVE模式,AVDD、DVDD正常输出;

2.在尝试建立通信时,BQ79631-Q1未回传任何数据,常拉高,BQ79631-Q1接收数据为80 00 03 0A 10 12 BE(启动TSREF基准输出指令),但TSREF未输出。

3.通信建立基础使用  推荐的    《BQ79616-Q1 软件设计参考》进行。

需要解决问题为,使用串口通信正常建立!

  • Hello, 

    From what I understand, you are having difficulty communicating to the BQ79631 through UART after waking up the device.

    Try sending [90, 00, 03, 0A, 01, D3, 7D] to turn on TSREF. This command fixes the command from a "Single Device Read" to a "Single Device Write" and changes the data frame to change the correct bit. The CRC will also reflect those changes. 

    By default, TSREF is on. If you also want to toggle TSREF off to confirm that UART communication is working correctly, send [90, 00, 03, 0A, 00, 12, BD].

    These commands should give a starting point for how the command frame should be structured to read/write from the device. If issues persist, I recommend using an oscilloscope on the RX pin to confirm that the communication frame is being sent correctly. 

    Sincerely,

    Michelle W. 

  • 你好!

    1.我们按照你所说的数据进行了尝试,对发送数据修改后,写入BQ79631-Q1,但TSREF仍旧不能输出。

    2.串口通信时,不能建立通信,有数据发送到BQ79631 RX,但BQ79631-Q1未回复任何信息,无响应。

  • Hello.

    This is our hardware drawings, the use of serial communication!

    SCH_MCU_2024-04-18.pdf

  • 1) Is the graph you shared before or after the digital isolator (ISO7742)? You may need to check the signal on the other side of the digital isolator to ensure that the signal is passing through correctly to the DUT. 
    2) Have you tried sending any read command to the device such as reading the DIE_ID? I'm just trying to confirm that this is a UART issue and not a TSREF issue. 

    Sincerely,

    Michelle W. 

  • 你好!

    逻辑分析仪数据读取为隔离器件输出信号侧(BQ79631部分),数字隔离器2端数据均有采集,波形一致。

    在唤醒命令发出后,BQ79631的DVDD与AVDD均有输出。按照规格书时序图看,BQ79631进入了ACTVE模式。但发送读取命令,BQ79631TX无数据。

  • Can you send what read command you are sending to the device to check the TX response? I just want to check that command frame is correct before I go further into debugging. 

    Sincerely,

    Michelle W. 

  • 你好!

    当前有进行命令读取写入,BQ79631-Q1   TX未进行回复,命令帧按照规格书输入的。

    请问方便提供一个完整通信的例程吗?

  •  MCU:TX = [80,00,05,01,01,F5,8F]: MCU:RX = high  79631:TX = high ;RX = [80,00,05,01,01,F5,8F]

  • Hello, 

    I'll do my best to test the BQ79631 on the bench tomorrow using an EVM to see if there is anything missing to configure the device. I'll probe the device using the oscilloscope and send scope shots of what I'm sending and the response received. 

    Sincerely,

    Michelle W. 

  • Could you please provide the sample source code of BQ79631? I just want to make sure my communication process is correct

  • Hello, 

    Try having the device address in communication equal to 1 instead of 0. For example: [80,01,05,01,01, CRC]. I found that the BQ79616 device (and most likely BQ79631) have a default device address of 1 instead of 0 when device has not been auto addressed. Let me know if there are still any issues communicating after trying this solution. 

    Sincerely,

    Michelle W.