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

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

Nenik — Sat, 01 Sep 2018 01:52:04 GMT

For your RC 32kHz oscillator question: The SoftDevice does support several modes of generating low frequency clock, but it needs to be told so.

Adafruit/Bluefruit.begin() is responsible for initializinf the SD and it does so (based on the USE_LFXO define) with NRF_CLOCK_LF_SRC_XTAL, that is, it claims there is a 32k xtal.

This define is pretty much hardcoded in platform.txt in the Arduino integration, though you might be able to override it if you define your own board - since you're using different hardware than nRF52 Feather, it is a sensible thing to do - I did so for my project, where I use nRF52 Feather mostly for prototyping, then deploy and test on a cusom board (even using different pin assignment).

But the code in AdafruitBluefruit::begin still misses the case for USE_LFRC, you'd have to add that too.

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

pbecchi — Fri, 31 Aug 2018 15:23:38 GMT

This behaviour is probably related to a delay(500) statement in main loop().. Delay() is used to put the processor in low power mode , so if there is no delay i will have a 6.4 mA floor level.

It look like for BT 832 power saving mode is entered only once every 2 cycles!

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

pbecchi — Fri, 31 Aug 2018 15:18:04 GMT

I have run several test this is final result that seam more SW than HW realated.

I have run same .hex ( a BLE peripheral UART example from Adafruit library) on BT832 and BT832X and I have different results.

Bt832

Bt832X

There is a 500 ms short pulse on BT832X that is much larger (about 500ms) in the BT832.

Inote:

1-horizzontal scales are differents

2-floor (minimum level) is similar 340uA (Serial is on);

3-pulse level in BT832 is 6.4 mA

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

MartinBL — Mon, 27 Aug 2018 08:47:59 GMT

It sounds strange indeed.

Could it be that if you don't configure the UART pins they are left floating, and due to some solder issue the pins are leaking current? While if you do configure the UART pins they are tied to the correct logic level and don't leak?

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

pbecchi — Fri, 24 Aug 2018 17:11:38 GMT

My application doesn't use UART, I have made one .hex without UART.init and one with UART.init.

The .hex with UART.init is the one of the PPK plots. The .hex without UART.init is the one of the first message (abnormal behaviour)!

I do believe that the difference from one module to another one is HW dependent....soldering of those LGA modules is not easy!

Anyhow I do not understand why the strange drain show up only if UART.init is not present (it should not be present, since UART lines are not used and there is the addition draw of 470 uA).

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

MartinBL — Fri, 24 Aug 2018 13:10:14 GMT

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.

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

pbecchi — Wed, 22 Aug 2018 20:15:21 GMT

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?

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

MartinBL — Wed, 22 Aug 2018 09:04:51 GMT

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.

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

pbecchi — Mon, 20 Aug 2018 12:58:53 GMT

Here you are:

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

MartinBL — Fri, 17 Aug 2018 12:03:29 GMT

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

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

pbecchi — Tue, 07 Aug 2018 19:18:12 GMT

Still waiting your comments......!

Thanks.

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

pbecchi — Wed, 01 Aug 2018 14:31:31 GMT

I received it yesterday...... I am probably not able to use it well!

I have just extracted a trace a power consumption during starting 36s (32 sec advertising+ 4 s central UART waiting for events)

What else can I do with PPK? There is any way to log data out of it?

What really you would like to see?

May be you can learn me on how to use better the PPK!

This by the way is the most favorable case ...the one with the lower power consumption!

Probably I may send same plot for the case of higher drain......

Let me know?

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

MartinBL — Wed, 01 Aug 2018 13:01:13 GMT

Hi,

Did you get your PPK yet? I think a plot of the current consumption is needed to figure out what goes on. There are too many unknown variables as it is now.

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

pbecchi — Wed, 25 Jul 2018 12:42:38 GMT

Hi Martin, thanks for your reply.

i did some additional test as i describe answering your question:

1. adafruit libraries use 11.0.0 SKD.

2.i had the power profiler kit in order since 2 weeks....waiting for restock......i will order it from elsewhere!

3.As far as i know, only BT832X has an internal DCDC converter.... I have tested his function in my code and got an important power saving.

4.I have tried several examples on BT832F BT832X and nRF52 DK. The only board that give always low uA is ddevkit. On my laast test I have assembled a new BT832X and this time got same high power drain as for BT832. I doubt it could be due to a combination of an HW and SW problem. Some results is described at this link:https://github.com/adafruit/Adafruit_nRF52_Arduino/issues/165. Fanstell modules are LGA type and since I have solder those myself , I am afraid there could be some short on GPIO locate on the hidden pads that i cannot reach and check. Neverless when I put a Serial.begin statement all strange behaviour is gone.........

5.I always upload identical .hex files, but i doubt is some chip could be on debug mode....how to check?

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

MartinBL — Wed, 25 Jul 2018 07:59:55 GMT

It should not be possible to run the code on the RC oscillator?
Yes, it is possible. How you do it depends on what SDK you are using?
Do you have any tools to measure and plot current over time? Average currents aren't very meaningful. 7 mA could e.g. be the CPU running constantly or the radio going haywire. If we could see a plot of the current over time we would probably be able to guess which one it is.
Do you know whether both the BT832X and F module are using the DCDC regulator? After skimming through the datasheets it seems like the BT832F does have the necessary components to use DCDC, while the BT832X doesn't. Do you somehow deal with this in your code?
Have you tried to run an example from the SDK just to compare the currents? If you still get high currents, then it could be a HW issue. Did you solder on the crystal? Could there be any accidental solder bridges drawing currents?
Are you running the exact same .hex-file on both modules?