nRF5 action!

[NeverDie]

Motivated by the above, I just now did some current tests on the nRF52832 and found that:

1. Going directly to an RTC sleep after powerup consumes 2.2ua.
2. Enabling DCDC doesn't increase that.
3. Nor does blinking an LED and then putting that pin into a disconnected state (D0) before sleep.

HOWEVER,
4. Activating Serial using Serial.begin(..) before sleep causes the current drain during sleep to rise to around 10.8ua. That was surprising to me, because this code in hwSleep(..) seems geared toward turning OFF serial prior to sleep:

  // Idle serial device
  NRF_UART0->TASKS_STOPRX = 1;
  NRF_UART0->TASKS_STOPTX = 1;
  NRF_UART0->TASKS_SUSPEND = 1;

So, I guess more is needed there?

[Toyman]

@d00616 thx. How do I use the macro? Just put in ISR?
Regarding the bug: if read the docs correctly, all nrf51 have the bug :-(

[Toyman]

@NeverDie do you use hwSleep() instead of sleep()?

[NeverDie]

@Toyman said in nRF5 Bluetooth action!:

@NeverDie do you use hwSleep() instead of sleep()?

Yes.

[NeverDie]

OK, I found that adding:

  NRF_UART0->ENABLE=0;  //disable UART0

brings the current consumption back down to 2.2ua during sleep. :)

[Toyman]

@NeverDie should it be placed just before hwSleep()?

[NeverDie]

@Toyman said in nRF5 Bluetooth action!:

@NeverDie should it be placed just before hwSleep()?

It's just a possible preliminary piece of the solution, because you'll need to renable UART0 after waking up from sleep. I haven't tested to see whether Serial.print(..) still works after re-enabling, or whether it needs to be re-initialized. Those are details yet to be sorted.

Or, maybe there's some other way of doing it. At this point, I'm just reporting my finding and tossing it out there as a tantalizing possibility.

[d00616]

@Toyman said in nRF5 Bluetooth action!:

@d00616 thx. How do I use the macro? Just put in ISR?

Yes. Give the event register as parameter.

Regarding the bug: if read the docs correctly, all nrf51 have the bug

This bug is listed as PAN#39 and fixed at the end of 2014.

[d00616]

@NeverDie said in nRF5 Bluetooth action!:

OK, I found that adding:
NRF_UART0->ENABLE=0; //disable UART0

brings the current consumption back down to 2.2ua during sleep.

Great work. Are you able to build an Pull Request fixing this? This Pull request should also be tested in the condition with a disabled serial port.

If you need help, please ask. I do the reviews.

[Toyman]

@d00616 said in nRF5 Bluetooth action!:

Yes. Give the event register as parameter.

so, if I have an intterupt atached to pin 1, what shall i put into ISR?
NRF_RESET_EVENT....;
Sorry for dumb questions, this is completely new to me.

[NeverDie]

@d00616 said in nRF5 Bluetooth action!:

If you need help, please ask.

What is it that I submit? A diff file or something? And I'm guessing I do it through github?

[NeverDie]

Just re-enabling the UART isn't enough. Nor are the existing UART related instructions after a wake-up, if UART0 was disabled. It seems to require a re-initialization. Another Serial.begin(BAUDRATE) after wake-up does work. However, I should point out that doing that isn't free, as it adds to wake-up time. So, you may wish to add another "level" of sleep, one which saves more energy while sleeping but at the cost of a longer wake-up. Moreover, the energy consumed during the longer wakeup isn't free either, so if the sleeps are very short, you could lose more energy for using it than not. One may, therefore, also want to calculate the breakeven point to provide guidance on when to use which level of sleep.

In short, this is more than a simple fix, and the software architect probably needs to consider the bigger picture in order to craft the best solution.

[Toyman]

Guys,

Have you seen this?

Note, that our beloved ebyte is not there, but PTR9618PA is

[NeverDie]

@Toyman said in nRF5 Bluetooth action!:

Guys,

Have you seen this?

Note, that our beloved ebyte is not there, but PTR9618PA is

It's useful. But just knowing the module exists is one thing. Finding a source for it is another.

[Toyman]

@NeverDie I believe, buying non-Chinese modules in retail is virtually impossible, but Xuntong, Skylab and Raytaq are available at Ali.
For me, the list is more like "quality assurance"

[d00616]

@Toyman said in nRF5 Bluetooth action!:

@d00616 said in nRF5 Bluetooth action!:

Yes. Give the event register as parameter.

so, if I have an intterupt atached to pin 1, what shall i put into ISR?

With arduino-nrf5, you can't put nothing into the pin interrupt ISR because the ISR is already defined.

Sorry for dumb questions, this is completely new to me.

There are no dumb questions, there are bad answers.

[d00616]

@NeverDie said in nRF5 Bluetooth action!:

@d00616 said in nRF5 Bluetooth action!:

If you need help, please ask.

What is it that I submit? A diff file or something? And I'm guessing I do it through github?

There is and document describing the procedure: https://www.mysensors.org/download/contributing

I think this is a good document to start with. If you have trouble, please ask.

[NeverDie]

@d00616
The solution I'm going with, which serves my present needs, is just to put all serial communications code within "DEBUG" compiler directives. So, if I'm not debugging, the issue just goes away, and there's no added overhead. :)

[NeverDie]

@NeverDie said in nRF5 Bluetooth action!:

@d00616
The solution I'm going with, which serves my present needs, is just to put all serial communications code within "DEBUG" compiler directives. So, if I'm not debugging, the issue just goes away, and there's no added overhead. :)

Found a shortcut. Instead of doing all that, which is extra work and looks ugly too, I just disabled the UART0 on the first sleep, and then never re-enabled it. It works. Now my sleep current is just 2.1ua, except for the brief pulses every 100ms where the PPI listens for an incoming packet addressed to it. :)

[NeverDie]

I was just checking the nRF51 datasheet, and I don't see much, if any, PPI control available. So, I suppose that's yet another reason for preferring the nRF52....