Sensor NRF24L01+ sleep current

[flopp]

@Yveaux
With a multimeter

[bjacobse]

True the NRF24L01+ shall use 900nA (0,9uA) in power down mode according to the spec.

What do you mean when stating "when I remove 3.3V for the NRF it goes down to ~15uA." - is the NRF still connected with data pins to the arduino? (I hope that NO arduino pins are providing HIGH output, while there is no power to the NRF, since this will kill the NRF24L01+

I understand that you are using a "good Quality" multimeter? else you can't trust your measured values.
and the gw.sleep(SLEEP_TIME) should sleep both Arduino + NRF24L01+

[tbowmo]

@flopp

It could also be fake NRF chips, it's seen before.

Also see this thread http://forum.mysensors.org/topic/1815/low-power-how-much-current-solved

And perhaps this http://forum.mysensors.org/topic/1153/we-are-mostly-using-fake-nrf24l01-s-but-worse-fakes-are-emerging

[flopp]

@bjacobse said:

What do you mean when stating "when I remove 3.3V for the NRF it goes down to ~15uA." - is the NRF still connected with data pins to the arduino? (I hope that NO arduino pins are providing HIGH output, while there is no power to the NRF, since this will kill the NRF24L01+

While arduino and NRF is in sleep I was measuring ~75 uA I disconnected the positive power cable for NRF and uA droped down to 15uA, BMP180 and stepdown was still connected.

I understand that you are using a "good Quality" multimeter? else you can't trust your measured values.
and the gw.sleep(SLEEP_TIME) should sleep both Arduino + NRF24L01+

I am using a Fluke 87V, not calibrated for a couple of years but I trust it within 5% that's ok for me at the moment
OK, that's perfect, then I don't have to think about sleep modes

[flopp]

@tbowmo

I have ordered 10 pcs NRF, lets see if they can go down lower then ~60uA when sleeping

Today I only have 2 NRF :grin:

[bjacobse]

@flopp
Yes replace NRFL2401+ with another NRF24L01+ to see if this make the current draw smaller - I think you can trust your Fluke 87V :-)

[flopp]

I change the NRF for sensor and now I measure 0,04mA(41,8uA) with all equipment connected

I am happy

[flopp]

I tried, before I changed NRF, to have use a digital output to feed my NRF.

i put

digitalWrite(4,HIGH);

at first row in SETUP

I also put

digitalWrite(4,LOW);

just before it go to sleep

but I then got "radio init fail", is it even possible to to it this way or can I have this type of function anywhere else in the code/file,?

[AWI]

@flopp When you power down the nRF you need to reinitialize it. But I doubt if it is worth the trouble as the radio consumes only a fraction of the total while sleeping.
Try making a node which powers up on interrupt only. The total consumption will go down to a little more than 1uA.

[flopp]

@AWI said:

@flopp When you power down the nRF you need to reinitialize it. But I doubt if it is worth the trouble as the radio consumes only a fraction of the total while sleeping.
Try making a node which powers up on interrupt only. The total consumption will go down to a little more than 1uA.

It is a sensor(node?) that measures temp and pressure. Is it possible to have interrupt?
today I use timer, 60 seconds.
I also use a clone NRF(maybe) because firt one i tried did use much more than 1uA, more something like 60uA

[bjacobse]

The timer can be set as an interupt
But sleep as MUCH as you can, this preserves your battery. So why measure every minute? if you can wait to measure every 5 minute, do so and prolong your battery :-) I know this depends on what you need the measurements to control, but "if its only" because you want to look at measurements in a graph, sleep for 5 min

[flopp]

At the moment I am measuring every minute to verify that it works correctly.

Later I will measure every 5-15 minutes.

gw.sleep(sleeptime);

is what I use, I have seen other have used Interrupt together with sleeptime, but it works fine for me, right now in sleep it is 40uA

Do I need to use interrupt for better power saving?

[bjacobse]

@flopp
This is the correct way, to sleep and use interrupt for this :-) so you are using interrupt
http://forum.mysensors.org/topic/417/gw-sleep-and-milis

[flopp]

@bjacobse said:

@flopp
This is the correct way, to sleep and use interrupt for this :-) so you are using interrupt
http://forum.mysensors.org/topic/417/gw-sleep-and-milis

Thanks