Wakeup and Sleep modes internal interrupt

[Mohamed O.Abouzeid]

Hello Guys,

I'm working in a project and I wanna turn off the radio "ble" and go to sleep, deep sleep to save the power, the current consumption while it's connected is 0.4mA which is too much, the point is that I want it to wake up without any external interrupt, I mean I wanna have a timer and each timeout, it wakes up and start advertising for a while, my problem is that I don't know how to turn off the radio completely and make it wake up consequently based on a timer.

Regards, Mohamed Osama

[endnode]

Hello Mohamed,

All the Q&S you read on this topic here on the forum are correct: there are only SLEEP and POWER OFF modes on nRF5x chips. The first one is used basically all the time (see power_manage() function typically called in main function inside infinite loop). Second one means that you basically shut-down the system and next time it is woken up (power power reset or NFC field in case of nRF52 or by GPIO interrupt) it will start like during normal power on reset event. However it is not possible to run any RTC or WATCHDOG or TIMER inside nRF5x during SYSTEM OFF, read more about it in Reference Manual (e.g. in chapter 12.1.5).

Cheers Jan

[Mohamed O.Abouzeid]

@endnode : Okay, that's good, but the current is too much, 0.4mA is a huge current, I tried to reduce the tx power to -30dbm, but it didn't help.still reading the same current.

[endnode]

400uA is some mean current but do you know exactly what is the power consumption curve over time in different moments and how it relates to radio and other functions being actively used? You can have many SW and HW bugs and debugging procedure is almost always the same: long time step-by-step slowly going from FW running on Dev Kit with power analyzer (to be sure that your FW is doing what it should do), confronting the curves with data sheets (what HW peripheral should take what power) and Errata, then going to your custom HW, doing stripped-down FWs to test each HW peripheral function separately and finally you can find the leaks. There is great guide from Stefan here.

[Jørgen Holmefjord]

You should be able to achieve much less than 0.4 mA when in system ON idle mode. If you are using the TIMER peripheral to wakeup the chip, this will require the high-frequency clock (HFCLK) to run. HFCLK adds 250-470 uA to the current consumption, depending on the usage. For low power you should use RTC instead, as the RTC runs on the low frequency clock (LFCLK). Also see this answer for more details.

[Mohamed O.Abouzeid]

@endnode , okay thank you, overall it varies between 0.38mA to 0.46mA, I will check the power with the links you said and will let you know, thanks for ur help