License incompatibility

[afaerber]

The README.md says: Modification and example comes from Snootlab with GPLv2 license.

The wiringPi library (#1) however is under LGPL-3.0+, which is incompatible with GPL-2.0 according to the FSF. You could use GPL-2.0+ instead (GPLv2+), which effectively makes the combined work (i.e., OTAA_JoinAndTransmit) GPL-3.0+.

Any lib/lmic/ files that are not marked EPL-1.0 are lacking license headers indicating their license, see also ernstdevreede/lmic_pi#2. That of course impacts which license your modifications can be under.

Your src/ example is lacking a license header, and no GPLv2 COPYING file is present in the project.

In case you're unfamiliar with the SPDX license identifiers, the + refers to the "or (at your option) any later version" half-sentence.