RE: What is sure way to power down unwanted nrf51822 subsystems?

Stefan Birnir Sverrisson — Mon, 10 Nov 2014 10:27:44 GMT

For you questions, take a look at this current consumption guide, specifically sections for the "Choice of 32 kHz clock source", "Choice of 16 MHz external crystal" and "Setup of SPI, UART, TWI interfaces". This thread and this thread are also good in terms of realizing the clock model and what is automatically turned on and what not.

RE: What is sure way to power down unwanted nrf51822 subsystems?

testy — Thu, 06 Nov 2014 20:36:13 GMT

According to my experience with UART:

when I enter system ON mode without

NRF_UART0->ENABLE = (UART_ENABLE_ENABLE_Disabled << UART_ENABLE_ENABLE_Pos);	// to save HFCLK+1V2 power

current consumption is roughly +1,0mA, because oscillator and voltage reference are forced to run permanently. So this is general advice. Take a look at Block resource requirements in PS.

Only sd_power_system_off() or NRF_POWER->SYSTEMOFF = 1; switches this kind of peripheral automatically OFF.