Power use with GPIOTE is too high?

RE: Power use with GPIOTE is too high?

Erland Lewin — Tue, 29 Oct 2013 17:02:24 GMT

It's the 1.2 volt voltage supply.

According to the Product Specification, table 27, the system will draw 810 uA when the 16 MHz crystal and 1.2V regulator are enabled.

RE: Power use with GPIOTE is too high?

Fred — Tue, 29 Oct 2013 16:34:48 GMT

Hi Marc Nicholas,what's mean with "1V2"?

RE: Power use with GPIOTE is too high?

Erland Lewin — Tue, 29 Oct 2013 15:50:05 GMT

Credit to Marc Nicholas for pointing out that this is hardware bug #39 documented in the v2.0 Product Anomaly Notification released today, apparently present in all versions of the chip.

I'd mark your comment as the correct reply, but as it's a comment to a comment, it appears that I can't.

RE: Power use with GPIOTE is too high?

Marc Nicholas — Tue, 29 Oct 2013 15:23:52 GMT

Have you read the PAN?

GPIOTE: 1V2 + HFCLK are requested always when the GPIOTE task is configured.

Symptoms: Excess current consumption in system ON mode when CPU is sleeping.

Conditions: One or more GPIOTE channels are configured in task mode.

Consequences: Battery life time is degraded.

Workaround: None.

RE: Power use with GPIOTE is too high?

Christopher Mason — Sat, 28 Sep 2013 19:59:37 GMT

FYI, I'm seeing similar behavior with GPIOTE causing about 1.2 mA current draw. In my application I can relatively easily enable/disable the GPIOTE when needed by setting the GPIO config mode to DISABLE when not in use.

RE: Power use with GPIOTE is too high?

Erland Lewin — Tue, 24 Sep 2013 19:05:47 GMT

Ok, I tracked this down further. I minimized the program, and the following line causes the program to draw about 950 uA:


	NRF_GPIOTE->CONFIG[GPIOTE_CHANNEL_NUMBER] = 
(GPIOTE_CONFIG_MODE_Task *shiftleft* GPIOTE_CONFIG_MODE_Pos)     |
                                         ((uint32_t)outPin *shiftleft* GPIOTE_CONFIG_PSEL_Pos)     |
                                         ((uint32_t)NRF_GPIOTE_POLARITY_TOGGLE *shiftleft* GPIOTE_CONFIG_POLARITY_Pos) |
                                         ((uint32_t)NRF_GPIOTE_INITIAL_VALUE_HIGH *shiftleft* GPIOTE_CONFIG_OUTINIT_Pos);

(There's apparently a bug in the forum, so I replaced two 'less than' with shiftleft above)

In the product specification, section 8.10 says the GPIOTE should only draw 0.1 uA "in Output mode". As far as I can understand, the above uses the GPIOTE in output mode (defines a task which toggles an output pin).

Please help me understand why the above line causes the GPIOTE to draw more than 0.1 uA!

RE: Power use with GPIOTE is too high?

Erland Lewin — Tue, 24 Sep 2013 04:32:19 GMT

I added code to power down peripherals as below, but I am still measuring 87 mV (=870 uA).


	// Disable unused peripherals
	// Radio:
	NRF_RADIO->TASKS_DISABLE = 1;
	NRF_RADIO->POWER = 0;
		
	NRF_POWER->POFCON = 0; // Disable Power Fail Comparator
	NRF_GPIOTE->INTENSET = 0; // Disable all GPIO interrupts
	NRF_TIMER0->TASKS_STOP = 1;
	NRF_TIMER0->POWER = 0;
	NRF_TIMER1->TASKS_STOP = 1;
	NRF_TIMER1->POWER = 0;
	NRF_TIMER2->POWER = 0;
	// NRF_WDT->CONFIG = 0;
	NRF_WDT->POWER = 0;
	NRF_RNG->POWER = 0;
	NRF_TEMP->POWER = 0;
	NRF_ECB->POWER = 0;
	NRF_CCM->POWER = 0;
	NRF_AAR->POWER = 0;
	NRF_SPI0->POWER = 0;
	NRF_SPI1->POWER = 0;
	NRF_SPIS1->POWER = 0;
	NRF_TWI0->POWER = 0;
	NRF_TWI1->POWER = 0;
	NRF_UART0->POWER = 0;
	NRF_QDEC->POWER = 0;
	NRF_ADC->POWER = 0;
	NRF_LPCOMP->POWER = 0;

RE: Power use with GPIOTE is too high?

Erland Lewin — Mon, 23 Sep 2013 18:37:09 GMT

I just found the discussion: "Why does my nrf51822 consume 1 ma in sleep"

I powercycled the circuit to disable the debug interface. This reduced the consumption from 1240 to 950 uA. Then I made sure the HF cystal was enabled, which reduced the power consumption ot 870 uA. Still a factor 100 too high, I think.

As you see in the code, I have not explicitly enabled any other peripheral modules. But it does seem like something is using the 16 MHz crystal. Could it be the GPIOTE? If so, how can I make it release the 16 MHz crystal?