SX127X compatibility with Sigfox


(Tidratec) #1

A quick question to the SX127X experts:

Is it possible to have a node that is compatible at the same time with a LORAWAN network (LORA mode) and the Sigfox network (FSK mode)?

On the STM32 Lorawan discovery board (using the SX1276), there is a "Sigfox ready" mention:

Is it possible or just a mistake?


(Jose Marcelino) #2

Yes it is possible, in fact a popular upcoming multi-protocol board is doing exactly that. :slight_smile:

Sadly the opposite isn't, i.e. using one of the many - and very cheap - Sigfox chips for LoRa.


(Moebius L) #3

Hello, does anybody knows more about how to convert a SX1276 to talk Sigfox?

I got a few Whisper Node LoRa boards, which are using RFM95 (SX1276), and I would like to get some experience with Sigfox as well.

Thank you


#4

If you just want to gain experience with Sigfox just contact the representing company in your country. Very likely they will send you a free sample module and an account for testing on their network if you have a serious use-case. At least in the Netherlands Aerea does that, they are very cooperative and answer any questions you have, they seem like an agile organisation to me with a “just do it” mentality.

But indeed the stated fact that an SX127x (with TCXO) can also be used for Sigfox communication is very interesting for mass-production: if one technology (or company) fails you can migrate to the other without having to upgrade / migrate your hardware (although large-scale software updates in the field are also a challenge).

And as described on the Sigfox makers site embedding Sigfox functionality on an SX1272 or SX1276 looks like a piece of cake.


(LoRaTracker) #5

Can anyone point out a Hope RFM9x or Dorji DRF127x style module that is available with TXCO ?

Nothing obvious to me on either manufacturers web site.


(Tidratec) #6

What’s the sleep consumption of a TCXO based module by the way? My understanding is it’s much more than one with an xtal. Do you have the value for the Murata module?


#7

Indeed the Murata CMWX1ZZABZ-078 module contains a TCXO according to specs.

However the datasheet doesn’t list the deep-sleep / hibernate current which is peculiar for a device targeted at low power applications.

This blog article also mentions a module containing a TCXO and explicitly mentions the high sleep current of 600 uA making it unsuitable for low power / battery operated devices when powered continuously.

Sigfox modules are also using TCXO I understand, however they are cheap and low power. As far as I understand they may have an external TCXO and probably switch off power to it. Eg, see the AX-SFEU example, note the Vtcxo at the power mode control block.

Beware: I’m not an expert nor do I have experience with these modules yet, just doing some googling :relaxed:.