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Custom board using BT832 and BT832X ...power drain issue.

pbecchi

I am new to Nrf52832.......I have started development of a custom board based on Bt832 and BT832X.

I have built 2 proto boards one with BT832F and the other with BT832X except that the HW is identical.

I have I prepared a code using AdafruitGLX Nfr Arduino libraries .This code is basically a BLE uart server , with a certain command will activate some Gpio port. 

The code works without any problem on Bt832X  and give an acceptable power drain of

1mA during advertising and

100uA during main loop.

Now I have tried the BT832 and I have discovered that same code works only if I add an external 32kHz oscillator.This is because the low freq. 9scillator is only present on Bt832X! It should not be possible to run the code on the RC oscillator? I haven't be able to do it!

But after having added a 32768 Cristal and 2 12pF capacitors I have run the same code on BT832F .......but with following power drain figures

7mA during advertising

3mA during loop if not connected

6mA during loop if connected.

I would like to understand what is going on!! Can anybody tell me?

  • 0 in reply to pbecchi

    Can you upload a screenshot showing the current consumption of the bad device?

  • 0 in reply to pbecchi

    In your first post you talked about 

    7mA during advertising

    3mA during loop if not connected

    6mA during loop if connected.

    Your screenshot looks quite normal and you are drawing 441 uA on average.

    A couple of weeks ago you also mention that "On my last test I have assembled a new BT832X and this time got same high power drain as for BT832". Is it so that what module you are using doesn't matter anymore? That points to a problem with your HW doesn't it?

    Can you please summarize your current situation and problems?

    Do you know what goes on in the areas I have marked with green here:

    Are you toggling on and off an LED for example? It could also be a peripheral (TWI or UART for example) that does some work.

  • 0 in reply to MartinBL

    Just to explain and summarise:

    All initial measurements have been done with a multimeter that normally give a inaccurate average measurement.

    All initial test where done with no UART while final ppk plots where both done with UART active.

    This explain why ppk average reading on BT832X exceed the one performed with the multimeter.

    I am not home now, but as soon as I am back, I will repeats PPK plots with disabled UART on BT832X , BT832 and nRF52DK.

    I have noted that abnormal consumption is related to UART....

    When UART is disabled I have found minimal drain on nRF52Dk and even less on BT832X, while I find abnormal values on BT832(the ones of first message).

    When UART is enabled I find higher drain (300 to 500uA) with similar results for all boards.

    Yes, the problem may be HW related...could be that with a faulty soldering of the BT832 LGA pins ...a UART pin could be grounded..... 

    Could this explain the UART related behaviour?

  • 0 in reply to pbecchi

    If the exact same .hex file produces different results on two different boards you can assume it is a HW or soldering issue:

    If you desolder a misbehaving module from a board, solder it onto another board, and the problem problem persists, then it is likely related to the module. 

    The UART peripheral uses the HF clock. This clock system draws ~470 uA. 

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