fix printf warnings

platformio.ini

@@ -34,7 +34,9 @@ extra_scripts = bin/platformio-custom.py
 
 ; note: we add src to our include search path so that lmic_project_config can override
 ; FIXME: fix lib/BluetoothOTA dependency back on src/ so we can remove -Isrc
-build_flags = -Wno-missing-field-initializers -Isrc -Isrc/mesh -Isrc/gps -Ilib/nanopb/include -Wl,-Map,.pio/build/output.map 
+build_flags = -Wno-missing-field-initializers
+  -Wno-format 
+  -Isrc -Isrc/mesh -Isrc/gps -Ilib/nanopb/include -Wl,-Map,.pio/build/output.map 
   -DHW_VERSION_${sysenv.COUNTRY}
   -DHW_VERSION=${sysenv.HW_VERSION}
   -DUSE_THREAD_NAMES