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Posted to dev@mynewt.apache.org by Marco Ferreira <m...@rco.cc> on 2017/11/06 23:30:14 UTC
LoRa power consumption
Hi everyone!
Does any of you have an idea what's the power consumption for Rx with LoRa?
Thanks
--
Marco
Re: LoRa power consumption
Posted by will sanfilippo <wi...@runtime.io>.
Marco:
I read the reference you quoted and this is using a different radio (RFMx 900 MHz radio). The semtech chip I referred to was the SX1276. No idea if there are other chips available that might give you lower power drain. I did a quick online search and found a datasheet for the RFM95/96/97/98 module and it says Lora receive current of 10.3mA. So not sure where the ~2mA came from.
You might be better off asking the Adafruit folks since all the numbers I have seen are around 10mA.
> On Nov 7, 2017, at 3:57 PM, Marco Ferreira <ma...@altitude.co> wrote:
>
> Thanks Will.
>
> The 10mA is sort of what I'ver been reading.
> Was just poking to see if anyone had different numbers based on real experience and/or with mynewt specifically.
>
> I'm specifically after the scenario were LoRa radio would be turned on to listen/receive for very short periods of time.
> I read on an Adafruit post that "The ~13mA quiescent current is the current draw for listening (~2mA) plus ~11mA for the microcontroller."
> That made me question if it'd be possible to bring LoRa power drain to only 2mA.
>
> source: https://learn.adafruit.com/adafruit-feather-32u4-radio-with-lora-radio-module/power-management
>
> Sent from Mailspring (https://link.getmailspring.com/link/local-6ba04289-2adc@MacBook-Air-4.local/0?redirect=https%3A%2F%2Fgetmailspring.com%3Fref%3Dclient&recipient=dev%40mynewt.apache.org), the best free email app for work
>
> On Nov 7 2017, at 1:14 am, will sanfilippo <wi...@runtime.io> wrote:
>> Marco:
>>
>> Not sure if you are referring to the current mynewt LoRa implementation or LoRa in general. The Semtech SX1276 chip draws 11-12mA in receive mode. The processor will add to this of course. If you are asking about mynewt specifically the current drain has not been measured but there are quite a few GPIO turned on plus the HFXO and the processor running so it will be more than that.
>>
>> The current drain will also change quite a bit based on the class of the LoRa device. Class C is constantly receiving. Class A is only receiving for a very short amount of time so the current drain will be considerably less. Lots of variables there; really only way to know is measure it.
>>
>> Will
>>
>>
>>> On Nov 6, 2017, at 3:30 PM, Marco Ferreira <m...@rco.cc> wrote:
>>>
>>> Hi everyone!
>>>
>>> Does any of you have an idea what's the power consumption for Rx with LoRa?
>>>
>>> Thanks
>>> --
>>> Marco
>>>
>>
Re: LoRa power consumption
Posted by Marco Ferreira <ma...@altitude.co>.
Thanks Will.
The 10mA is sort of what I'ver been reading.
Was just poking to see if anyone had different numbers based on real experience and/or with mynewt specifically.
I'm specifically after the scenario were LoRa radio would be turned on to listen/receive for very short periods of time.
I read on an Adafruit post that "The ~13mA quiescent current is the current draw for listening (~2mA) plus ~11mA for the microcontroller."
That made me question if it'd be possible to bring LoRa power drain to only 2mA.
source: https://learn.adafruit.com/adafruit-feather-32u4-radio-with-lora-radio-module/power-management
Sent from Mailspring (https://link.getmailspring.com/link/local-6ba04289-2adc@MacBook-Air-4.local/0?redirect=https%3A%2F%2Fgetmailspring.com%3Fref%3Dclient&recipient=dev%40mynewt.apache.org), the best free email app for work
On Nov 7 2017, at 1:14 am, will sanfilippo <wi...@runtime.io> wrote:
> Marco:
>
> Not sure if you are referring to the current mynewt LoRa implementation or LoRa in general. The Semtech SX1276 chip draws 11-12mA in receive mode. The processor will add to this of course. If you are asking about mynewt specifically the current drain has not been measured but there are quite a few GPIO turned on plus the HFXO and the processor running so it will be more than that.
>
> The current drain will also change quite a bit based on the class of the LoRa device. Class C is constantly receiving. Class A is only receiving for a very short amount of time so the current drain will be considerably less. Lots of variables there; really only way to know is measure it.
>
> Will
>
>
> > On Nov 6, 2017, at 3:30 PM, Marco Ferreira <m...@rco.cc> wrote:
> >
> > Hi everyone!
> >
> > Does any of you have an idea what's the power consumption for Rx with LoRa?
> >
> > Thanks
> > --
> > Marco
> >
>
Re: LoRa power consumption
Posted by will sanfilippo <wi...@runtime.io>.
Marco:
Not sure if you are referring to the current mynewt LoRa implementation or LoRa in general. The Semtech SX1276 chip draws 11-12mA in receive mode. The processor will add to this of course. If you are asking about mynewt specifically the current drain has not been measured but there are quite a few GPIO turned on plus the HFXO and the processor running so it will be more than that.
The current drain will also change quite a bit based on the class of the LoRa device. Class C is constantly receiving. Class A is only receiving for a very short amount of time so the current drain will be considerably less. Lots of variables there; really only way to know is measure it.
Will
> On Nov 6, 2017, at 3:30 PM, Marco Ferreira <m...@rco.cc> wrote:
>
> Hi everyone!
>
> Does any of you have an idea what's the power consumption for Rx with LoRa?
>
> Thanks
> --
> Marco
>