Error during compilation

This is my first attempt at getting a LoRaWan gateway and node to work

The gateway is a single channel gateway based on the code from
github/things4u/ESP-1ch-Gateway written by Maarten Westenberg.
I am using an esp32 and a rfm95w radio.

I am using the arduino ide for building the project.

When buiding the project I get and error shown below:

Compiling sketch…
/home/jrm/Documents/test/ESP-sc-gway/_txRx.ino: In function ‘int buildPacket(uint8_t*, LoraUp*, bool)’:
_txRx:266:42: error: ‘checkMic’ was not declared in this scope
checkMic(message, messageLength, NwkSKey);
I tried searching for the checkMic routine but couldn’t find it.
Also, there are no #include files in the _txRx.ino file.

Anyone have an idea of why this could be happening?
Its kind of puzzling because the #if statement looks like this:

#if _CHECK_MIC==1
unsigned char NwkSKey[16] = _NWKSKEY;
checkMic(message, messageLength, NwkSKey);
#endif //_CHECK_MIC

and I don’t even know how _CHECK_MIC is known in the file
since there are no #include files.

Thanks for your help

Single channel packet forwarders harm the LoRaWAN network and are incompatible. They’re not supported on TTN and should not be used,
This forum does not provide support for them.

Maybe it’s not a single channel packet forwarder then. It’s a single channel gateway that doesn’t harm anything that I know. The library used is the arduino-lmic by matt. Maybe I just posted in the wrong section.

There is noch thing as a single channel gateway. The LoRaWAN specification requires a gateway to have multiple channels. The hardware usually used has 8.
And a module with just one channel will hurt the network.

Unfortunately its not a case of what you dont know does not cause any harm.

So why have a section for single channel gateways in the forum ?

Because 4 years ago it seemed a good idea, now we know about the issued caused by them.

Ok, thanks