Custom frequencies for Twig - Serial RF Pro

The Serial RF Pro is documented as supporting frequencies 433/470/868/915 MHz.

However, in the command description it is clear that you can actually encode an arbitrary frequency as the argument of the command:

Is it actually possible to specify a frequency other than 433/470/868/915 MHz, obviously within some hardware limitations? I’d like to use 904 MHz and interface with some other hardware that I know to be using that frequency.

The module could be configured working at different frequency. But the RF transmitting power will not as good as it is matching in itself frequency physically, because different module has a specific RF front circuit for different frequency.


It looks like Serial RF Pro is using HopeRF HM-TRP-433, and the specifications sheet for that module says it has a minimum 414 MHz, typical 434 MHz, and max 454 MHz.

The other frequency bands (470/868/915 MHz) apply only to those other HopeRF modules (HM-TRP-470, HM-TRP-868, HM-TRP-915) which are not used by Serial RF Pro, so it is wrong to mention them in any of the Seeedstudio details. You should only describe 414 MHz to 454 MHz as its range.

Alternatively, would it be possible to get a version of Serial RF Pro based on HM-TRP-915? I am very interested in a project that requires that frequency range. I’ve created a “wish” for it here: