Using 868Mhz modules : Success


I had a couple of HM-TRP modules laying around, and gave them a try. However my modules were 868Mhz ones. So I went through the code, and it seems that the bootloader supports 868Mhz, but the initialisation part of the firmware is only for 434 and 915Mhz. Anything else is falling back to 915Mhz init register set.


Interestingly the register tables above 19kbps are the same for 434Mhz and 915Mhz, so I assumed that 868Mhz sould work. And it seems to be a right assumption, I managed to get a solid link between two 868Mhz modules. I did not made a range test, but within a couple hundred meters it was fine.




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  • Developer

    Hi Andras,

    After seeing this posting I have added the 470MHz and 868MHz register tables to the SiK firmware. If you update to the latest 3DR radio firmware you will get full support for your 868MHz radio.

    Cheers, Tridge

  • Dear Andras,

    I bought a couple of 868MHz module and I don´t know how to make them work

    Could you please help me.

    I put every module in a litle text board this board is attached to a normal FTDI Basic 

    I conected this way

    FTDI         Module

    VCC         3,3V regulator  VCC

    GND         GND

    TX            Rx

    Rx           Tx

    DTR         NONE

    CTS         NONE

    I have send some sentences from a Hyperterminal Program connecting  @ 9600bps with the Com port (USB) and @57600  and they work, I know because I put a bridge ai the air module Tx-Rx and I receive at the computer the same sentence I write.


    When I try to connect them to the 3DRadio Config program and there is no way of connecting them

    Could you please tell me some advice.




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