setFrequencySubBand?

[simeoni lorenzo]

Hello guys, I’m trying to understand well the code in exemple for mDot, and I see a function, FB_915 that i don’t really understand, and they say that with this function you had to be in USA, why? And what function use if I’m in Europe plz? 🙂

[Mike Fiore]

Simeoni,

Can you provide a link to the example program you’re referring to?

The frequency band of the device is normally stored in protected device configuration and can’t be changed by software.

Some documentation about LoRa and an introduction to LoRa can be found in the links below.

LoRa

Introduction to LoRa

Cheers,
Mike

[simeoni lorenzo]

Hello! For exemple, here https://developer.mbed.org/teams/MultiTech/code/Dot-Examples/docs/tip/ in Dot_util.cpp!:)

[Mike Fiore]

There’s no reference to FB_915 in that file. There is a reference to FB_EU868. Perhaps you’re referring to the debug output from the example program.

The function that reference is in is just displaying the current device configuration. Some configuration items are only relevant for certain frequency bands, so the code is switching on the frequency band in order to only show relevant configuration.

Your mDot was programmed in the factory to operate in a certain frequency band. The band your device is configured for should come out as part of the debug output from the example program. It should also be on the sticker on your mDot.

[simeoni lorenzo]

I’m trying to not use the library dot_util.h for the moment, i try to make all my program with only mdot.h, I don’t know if I really need to use dot_util.h

[simeoni lorenzo]

It’s in mDot.h that we see that the function is only used in USA with FB_915

[Mike Fiore]

The Dot-Examples code show how to use the Dot library in your application.
You’re free to use that code as a starting point or write your own code from scratch, but stealing code from the Dot-Examples might make things a bit easier.

[simeoni lorenzo]

Ok thanks man!:)

[Mike Fiore]

The 915 band is divided into 8 frequency sub bands because there are 64 uplink channels and the gateway can only listen on 8 at a time. So this setting (1-8) must match on the Dot and the gateway. The device will only transmit on the 8 channels in the sub band if the setting is between 1 and 8. If the setting is 0, it will hop all 64 channels.

/** Set frequency sub band
* only applicable if frequency band is set for United States (FB_915)
* sub band 0 will allow the radio to use all 64 channels
* sub band 1 – 8 will allow the radio to use the 8 channels in that sub band
* for use with Conduit gateway and MTAC_LORA, use sub bands 1 – 8, not sub band 0
* @param band the sub band to use (0 – 8)
* @returns MDOT_OK if success
*/
int32_t setFrequencySubBand(const uint8_t& band);

Cheers,
Mike

[Author]

Posts