The TX power from ADR is not used

[terrillmoore]

Although there is an elaborate mechanism for ADR in the LMIC code, LMIC.adrTxPow (which repersents the ADR adjusted TX power in dBm) is not used.

Transmit power is controlled (in radio.c) by LMIC.txpow. For US915, LMIC.txpow is unconditionally set to 26dBm for 500kHz channels, and to 30dBm for 125kHz channels.

(Further muddling things, radio.c for the sx1276 appears to only set the power to a max of 10 dBm -- it doesn't seem to correctly program the 20dBm boost mode. In any case, the setting of LMIC.txpow has basically no effect, because both values are greater than 15, and any value greater than 15 is mapped to 15 by radio.c.)

So it appears that the Tx Power is basically fixed (for US915), and the only thing that ADR can really adjust is data rate.