RAK2287 - Frequency band resistor

[nicolasech (Nicolas)]

Hello,

I have a doubt regarding RAK2287 concentrator. I bought AU915 version but now I am requiring to use EU868.

From the datasheet I understand that the RAK2287 supports many regions and these are configurated by firmware:

But I noticed that the board has in the silkscreen the labels EU868 and AU915, each one with a resistor on its side. My RAK2287, for example, has only assembled the resistor that’s labeled as AU915:

(I hope you can see the resistor in the image)

On the other hand, on the RAK store web page, the images show that the resistor assembled is the one labeled as EU868:

So, my question is: does the frequency selected on the RAK2287 depend merely on firmware configuration or does it depends on a hardware configuration?

For EU868 can I use my RAK2287 purchased as AU915?

Thank you for your help.

[Hobo (Vladislav Yordanov)]

Hei @nicolasech ,

The answer is unfortunately in this case that the Hardware determines the band of operation. In your particular case you can not go from AU915 to EU868, be simply tweaking the firmware. You will need another concentrator, all together.

Regards
Vladislav

[nicolasech (Nicolas)]

Thank you @Hobo

Perhaps changing the resistor (mentioned in my question) will do the trick and switch frequency?

[Hobo (Vladislav Yordanov)]

Hei @nicolasech ,

This is not going to solve it for you. There are hardware differences between the concentrator modules, that go beyond the resistor.

Regards
Vladislav

[cstratton (Chris)]

@nicolasech

Perhaps changing the resistor (mentioned in my question) will do the trick and switch frequency?

No.

The resistor has no electrical function at all, it’s just a dummy indicator component put in one spot or the other to indicate that the build was created with the the installation of the actually important parts having the values needed for 868 or 915.

[nicolasech (Nicolas)]

@Hobo @cstratton understood, thank you!