bq76pl455a自动监控,以及电压数据读取

1.手册上写了,使能了自动监控,在mcu读取电压的数据是不是要使能自动监控?

2. nSent = WriteReg(nDev_ID, 2, 0x01, 1, FRMWRT_SGL_R); // send sync sample command

    nSent = WaitRespFrame(bFrame, 39, 0);//cell value form 16->1(value*5/65535), aux, dig temp, ang temp

   使用上面两句读取数据,为什么读出来的数据都是不变了?还有哪里需要设置?

3. 

nSent = WriteReg(nDev_ID, 2, 0x007FFFFFC000, 6, FRMWRT_SGL_NR); // send sync sample command with channel
nSent = WriteReg(nDev_ID, 2, 0x20, 1, FRMWRT_SGL_R); // send read sampled values command
nSent = WaitRespFrame(bFrame, 27, 0); // 15+8+2 bytes data + packet header + CRC, 0ms timeout

使用以上三条读取数据是可行的。

  • Hi,

    A1: Yes, MCU must monitor the data

    A2: Please make sure all the setup steps outlined in sections 1 and 2 of the bq76PL455A-Q1 Software Design Reference are followed (www.ti.com/.../slva617a.pdf), for example, auto-addressing and initialization.

    A3: You must follow the steps outlined in section 4 of the bq76PL455A-Q1 Software Design Reference (www.ti.com/.../slva617a.pdf)

    Best Regards,
    Gene
  • 回复 Gene Qiu:

    1. 是否使能了自动监控,MCU可以不去读电压或者错误,等待错误中断就行。。。还是自动监控每采集一帧就不采集了?要MCU把电压数据读走,才会采集下一帧。这一点还没有理解?

    2. 在读取数据的时候偶尔会读到很多是0的,是不是通信出错了?我波特率为250K。

    3.我使用了两片455a板子,发现最底的455a耗电比上端的快(有MCU侧给底端的供电)。理论上顶端耗电更多些,但事实上没有,这种问题应该如何解决。

  • 回复 wen tang4:

    Hi

    1. If using the FAULT lines, the MCU can be programmed to use them as interrupts. But for reading voltages, as well as manually reading fault registers, the PL455 device must be sent a command to manually read the registers. You would need to program the device to read these voltages at defined intervals.

    2. If you are reading 0 V, it may be that the ADC has not finished converting its measurements. Please ensure the proper delays are inserted to allow for the ADC to finish measurement conversions.

    3. For the bottom board, please ensure that there are no external loads on the device (resistor ladders could cause additional current draw, as well as ensure that all the same interfaces are the same between the top and bottom board. Finally, ensure that the base device's SW2 is set in the proper position for single ended communications (both switches to the left, towards the UART connector). Otherwise the UART communications will be using the PL455 internal power supply instead of the external microcontroller's (or PC's) power line.

    Best Regards