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Anarduino+RF96 put to sleep mode  XML
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d00m



Joined: 19/10/2015 17:21:10
Messages: 32
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Hello

How to put to sleep mode Anarduino+RF96 ?

I need my device sleeping and once in minute wakeup and send data.
Don't know how to do it.
Please advice.

stevech



Joined: 07/07/2014 18:07:27
Messages: 91
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is the receiving device also sleeping? Or is the receiving end a "hub" that's always-on?

If both sleep, you need good time sync between the two. And RH doesn't do that. It's more complex than you'd imagine.

Hopefully, you system is a star topology with a mains-powered hub.
d00m



Joined: 19/10/2015 17:21:10
Messages: 32
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RX device doesn't need sleep mode, and can wait some time for receiving data, so it's no big issue for my task.

Seems now everything works good except power consuming.
In sleep mode TX device consume about 0.9mA
but i've read that it possible get about ~16uA
http://forum.anarduino.com/posts/list/39.page#238

I've also desoldered that resistor but it didn't help.

So I think something wrong with sleep mode.

Im using LowPower library:

empeka



Joined: 21/12/2014 05:56:01
Messages: 18
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radio module and spi flash have to be put to sleep before MCU
d00m



Joined: 19/10/2015 17:21:10
Messages: 32
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empeka wrote:radio module and spi flash have to be put to sleep before MCU


thank you, I've also read your answer in this topic http://forum.anarduino.com/posts/list/39.page
and hope that I will get the same power consumption as well

but do I have SPI flash on my Anarduino+RF96?
Also - if I do radio.sleep, it is strange but then power drain is increasing
d00m



Joined: 19/10/2015 17:21:10
Messages: 32
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well, I've got some results:

I powered my Anarduino via USB-FTDI adapter, jumper set in 5V mode (in 3v mode my multimeter goes crazy and nothing works until I disconnect it from chain)

I've added SPIflash library and changed code:

// Enter power down state for 8 s with ADC and BOD module disabled
flash.sleep();
driver.sleep();
LowPower.powerDown(SLEEP_8S, ADC_OFF, BOD_OFF);
LowPower.powerDown(SLEEP_8S, ADC_OFF, BOD_OFF);

now I have 43-44uA in sleep mode.
no 16uA as mentioned here http://forum.anarduino.com/posts/list/39.page#238 but still not bad

maybe I need power my system via 3.3v power supply ? I definitely will need some battery for this, and connect it directly to Vcc instead Vin. Any reccomendation?

as for ~43uA - not bad.. but:
also I have 7 termosensors DS18B20 in my system. And if these sensors connected - power drain increases to 0.2mA in sleep mode.
need to do something to reduce this consumption in sleep mode time.


This message was edited 1 time. Last update was at 30/10/2015 12:57:07

empeka



Joined: 21/12/2014 05:56:01
Messages: 18
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now I have 43-44uA in sleep mode.


that's possible acording to spansion flash's datasheet.
see table here

Try without flash chip soldered, if you have proper tools to remove it.

also I have 7 termosensors DS18B20 in my system. And if these sensors connected - power drain increases to 0.2mA in sleep mode.


They don't have to be powered all the time. Turn them on only when you need them.
Assuming that max operating current of DS18B20 is 1.5mA, you should be completely safe feeding them from digital IO port.
(recommended max current of digital IO pin of atmega328p is 20mA)

Or (more properly) power your sensors from separate circuit turned on with mosfet.
empeka



Joined: 21/12/2014 05:56:01
Messages: 18
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I definitely will need some battery for this, and connect it directly to ??? instead Vin


mcp1703 quiescent current is ~2uA, so i wouldn't bother with powering board directly
d00m



Joined: 19/10/2015 17:21:10
Messages: 32
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Try without flash chip soldered, if you have proper tools to remove it.

no, I have not such tools..
I run flash.sleep(); so I suppose it will be enough for save power.

They don't have to be powered all the time. Turn them on only when you need them.

I did it - I power sensors via pin 7, put it to LOW before sleeping and turn to HIGH before measurement.

Now I have 43-44uA in sleep mode with termosensors connected.
I think there no more variants to reduce power drain.

Thank you.
 
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