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Topic: Lowest consumption issue (Read 207 times) previous topic - next topic

philgeek

Hello

When using my MKRFOX1200 supplied through 3.3V / Vin , I Can't get a lower consumption than 1.2 mA during LowPower.deepsleep(120000); instruction time (using <ArduinoLowPower.h>).

My test bench uses the simpliest hardware and software (nothing enabled, no LED ... ).

I've double checked this measure using my multimeter (very low quality) in serie (current measure) and in parallel (voltage measure) accross a 100 Ohm resistor in serie with the power supply : 120 mV drop ...

Unfortunately it is not enough efficient to be powered during monthes through a pair of AA alcaline batteries, even if my module sleeps always ... I was expecting less than 100 uA reading the Atmel SAMD data sheet ...

I could see two possible issues :

- The mkrfox1200 hardware design doesn't allow to get better results (ex. due to the clock input ... I don't know ...)
- The Arduino LowPower library doesn't do enough and could be optimized ...

As I've not got enough time to check by myself those two issues, I just hope that someone or a support can tell me what objective can be set  and how to proceed in order to get it. I wouldn't like to spend efforts targetting a non feasible objective, and some other messages on the forum are not enough conclusive on this topic ...

Sleep mode conumption parameter should be written in the MKRFOX1200 documentation, when it's said that the board can be supplied through AA batteries ...

Sorry for the English and the message form, I'm constrained by a Parkinson disease ... however compatible Arduino practice  :)

philgeek

I did a mistake in my description, sorry : the board is supplied through the battery connector and not through Vin !

philgeek

I've got a piece of information from technical support / Carla :

"After run some tests on this board, we have reached 300uA with a MKR Fox 1200, so we recommend you to update the low power library to get the improvements."


I had not yet time enough to experiment. I've seen on github a 1.2.0 version (instead of 1.0.0 in my Arduino IDE) but I can't see any major change which could improve my configuration. Anyway, I will do the comparison, for sure.

And now, I know the target/feasibility thanks to Carla.

Again, I would appreciate to get results from others. Thanks. Philippe.

philgeek

Reading the code of the low power library, I can see that the option BOARD_HAS_COMPANION_CHIP is not setup. Unfortunately this doesn't give us the capability to use the instruction LowPower.companionSleep(); and to ensure that the sigfox module by itself is set in deep sleep mode as well as the SAMD CPU.

In my test bench I did'nt initialised the sigfox module. I was expecting  the sigfox module to be its lowest consumption mode after reset. Furthermore I didn't call a SigFox.end() instruction. Maybe the mistake is there, I don't know ...

I definitively would appreciate to get support on this topic.

Please tell me anyway how you've got  happy with the lifetime of your "AA" battery back !

Philippe.

philgeek

I've updated the Arduino Low Power library to 1.2.0, I've called sigfox.end();   : I get 500 uA (+/- 100 uA) during the sleep mode. Progress, yes, but not as much as expected reading the components data sheet + MKRFOX1200 schematics.

End of my posts on that subject.














philgeek

Sorry, but I'm coming again a last time in order to provide a fruitful issue .

I've tried "to remove  the pin initialization in wiring.c", as suggested in other forums :

https://github.com/arduino/ArduinoCore-samd/blob/master/cores/arduino/wiring.c#L85

And now my consumtion in standby is about 50uA, difficult to be more precise with my multimeter ...

I've not seen negative side effects, anyway.

I can close the topic as SOLVED, and maybe my trials will help others ...

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