nRF5 action!

NeverDie

@NeverDie said in nRF5 Bluetooth action!:

So, to move forward with this, I took a super-stripped down nRF52832, and loaded it with a super stripped down sketch that never initializes the radio and pretty much just jumps directly into a long RTC 12 hour slumber using the MySensors sleep routine. Measuring the current drawn while in that slumber using a uCurrent Gold, I'm reading about 9.3ua. So, to confirm that, I'm running the same stripped down setup from a 10F supercap, and I'll see at what rate the supercap voltage drops with time, and whether that appears to agree or not with these initial measurements.

Hopefully the current draw will remain low, and there will be no surprises. In that case, I'll add stuff back in until I find the culprit that was previously causing the higher current draw.

It turns out that the culprit was the mere act of using pinmode to designate a pin as an input pin, even if it's not connected to anything. Then, during sleep, the current consumption is an order of magnitude higher. This is quite different behavior than on, say, an Arduino pro mini, where the input pins are high impedance and there's neglible current draw.

Not sure what to do about it though. Any ideas?

NeverDie

The same sort of thing happens if pinmode is used to designate a pin as an output pin--again, even if nothing is connected to it.

This is a potential show stopper. This module is useless to me if I can't connect it to anything.

As a workaround, is there some way to designate a pin as undefined again after having used pinmode to define it as either an input pin or an output pin?

NeverDie

Well, setting the pinmode to OUTPUT and then digitalwriting it to LOW seems to help considerably--at least when it's not connected to anything.

[Edit: Setting it to HIGH also helps similarly.]

NeverDie

Anyhow, I'm relieved that the radio isn't the source of these power drain problems. This pinmode stuff is a bummer, but it looks like I can at least partially work around it.

d00616

@NeverDie said in nRF5 Bluetooth action!:

Well, setting the pinmode to OUTPUT and then digitalwriting it to LOW seems to help considerably--at least when it's not connected to anything.
[Edit: Setting it to HIGH also helps similarly.]

Thank's. I check this after I fixed the Radio.

Actually, I have this board running. I measure a voltage of 0.13mV=6,6µA at the shunt with a simple sleep sketch. When I switch two pins into INPUT_PULLUP, then I measure 0.15mV==7,5µA.

When I switch on the LED then I measure 12.75mV == 0,6375mA, One pin in OUTPUT_H1H0 mode. With LED off I measure 0.15mV==7,5µA.

My MCU is nRF52832 QFAAB0 1615AX

P.S.: I have no documentation about the board. When I measure the boards current, then I have an shunt factor of 22,5. I think calculating with 20 is ok.

NeverDie

@d00616
Thanks! I just now ordered one of your boards so that in the future we can share a common platform for comparing numbers. :)
https://www.aliexpress.com/item/NRF52832-Mini-Development-Board-Gold-Core-board-Wireless-Bluetooth-Transceiver-Module/32798618219.html?spm=2114.search0204.3.1.GUmybP&ws_ab_test=searchweb0_0,searchweb201602_4_10152_10065_10151_10130_5490020_10068_5430020_5410020_10307_10137_10060_10155_10154_10333_10334_10056_5370011_10335_10055_10336_10054_10059_10332_100031_10099_5400020_10103_10102_10052_10053_10107_10050_10142_10051_10324_10325_5380020_10326_5390020_10084_10083_10080_10082_10081_10178_10110_10111_10112_10113_10114_10312_10313_10314_10316_10078_10079_10073_5420011-10332_10333,searchweb201603_5,ppcSwitch_4_ppcChannel&btsid=78a27a2f-4aa5-49a0-a538-502a2c86d8f2&algo_expid=598ae4bb-6401-4529-89ad-6e8d8a90af12-0&algo_pvid=598ae4bb-6401-4529-89ad-6e8d8a90af12&transAbTest=ae803_3

[By the way, I did my measurements on an Ebyte nRF52832 module]

scalz

in that case, you need to set it as a floating input i think, like it's generally at reset.
In datasheet, section 20 (p111), is explained how works the GPIO. You have a Bit for disconnecting it. See the PIN_CNF[n] registers. For instance, p.140, you can see how it looks for the P0.10, and the Bit 1.
This should do the job..

d00616

@NeverDie said in nRF5 Bluetooth action!:

Thanks! I just now ordered one of your boards so that in the future we can share a common platform for comparing numbers.

Ok. I have measured my Ebyte with the same sketch and in the µA range of my VC165 multimeter. Sleep current is 9.9µA with two ports in INPUT_PULLUP and one Port in OUTPUT_H0H1 mode. (b.t.w. this module costs actually 3,82€)

@scalz said in nRF5 Bluetooth action!:

in that case, you need to set it as a floating input i think, like it's generally at reset.
In datasheet, section 20 (p111), is explained how works the GPIO. You have a Bit for disconnecting it. See the PIN_CNF[n] registers. For instance, p.140, you can see how it looks for the P0.10, and the Bit 1.
This should do the job..

Should I add a DISCONNECTED mode to hwPinMode()?

NeverDie

@d00616 said in nRF5 Bluetooth action!:

Sleep current is 9.9µA with two ports in INPUT_PULLUP and one Port in OUTPUT_H0H1 mode....

Ah, maybe that's part of the difference. I was doing just:

pinMode(ALPHA_PIN, INPUT)
pinMode(BETA_PIN, OUTPUT)

because that's how I would have done it on an Arduino. Should we instead always use INPUT_PULLUP and OUTPUT_H0H1 instead?

rmtucker

@NeverDie
Should be

hwPinMode(DIGITAL_INPUT_SENSOR, INPUT_PULLUP);

According to NRF5 platform

NeverDie

Thanks! Somehow didn't remember that.

So, as suggested by @scalz what is some example code that can be used to "disconnect" the pin later?

rmtucker

@NeverDie
He has not added that facility yet,i think he asked you if you wanted it adding to the code?

NeverDie

@rmtucker said in nRF5 Bluetooth action!:

if you wanted it adding to the code?

Definitely!

scalz

for unused pins, it should be floating, not pullup. set the pin register you need to 0x02.
Something like that
NRF_GPIO->PIN_CNF[ulPin] = 0x02;
that will put pin in same state like it's on reset. Everything disabled/default, floating, with disconnect bit set.
(see datasheet gpio).

@d00616 said in nRF5 Bluetooth action!:

Should I add a DISCONNECTED mode to hwPinMode()?

make sense to have it for input too.. i agree :simple_smile:

NeverDie

Maybe add:
OUTPUT_D0D1 -> Disconnected 0, Disconnected 1
or similar to your list as another easy way to effectuate the disconnect?

NeverDie

It finally makes sense now as to why there were all those "disconnected" choices among the various OUTPUT options. In my case, for controlling whether the solar panel is connected or disconnected, choosing OUTPUT_S0D1 works perfectly. :)

So, I suppose another way to disconnect an input pin would be to redefine it as an OUTPUT pin with a disconnect state, and then immediately put it into the disconnected state.

rmtucker

@d00616 said in nRF5 Bluetooth action!:

@rmtucker said in nRF5 Bluetooth action!:

Yes being able to change the prescaler dynamically would help a great deal as 125ms / 582.542 hours is not really useful for most applications with a 250ms overrun.

The sleep() function is now more precise for sleeping <512s:

https://github.com/mysensors/MySensors/pull/909

The PR is waiting for merge.

Hmm just tried the latest commit and it is giving me 306ms for sleep(10000).
Something not quite right.

NeverDie

@rmtucker
How are you measuring how long it's sleeping?

rmtucker

@NeverDie said in nRF5 Bluetooth action!:

@rmtucker
How are you measuring how long it's sleeping?

Just using hwMillis() before and after sleep and subtracting one from the other.
It was just reading + 250ms until @d00616 commited some changes a few hours ago.

rmtucker

something wrong in here:-

// Calculate sleep time and prescaler
		if (ms<512000) {
			// prescaler 0, 30.517 μs resolution -> max 512 s sleep
			MY_HW_RTC->PRESCALER =  0;
			// Set compare register to 1/30.517 µs to garantee event triggering
			// A minimum of 2 ticks must be guaranteed
			// (1000/32768)<<12 == 125
			MY_HW_RTC->CC[0] = max((ms<<12 / 125), 2);
		} else {
			// 8 Hz -> max 582.542 hours sleep.
			MY_HW_RTC->PRESCALER = 4095;
			// Set compare register to 1/125ms
			// A minimum of 2 ticks must be guaranteed
			MY_HW_RTC->CC[0] = max((ms / 125), 2);
		}

nRF5 action!

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