moving build selection into platformio.ini rather than nasty #defines. thanks to @sensorslot

for the pointer to https://github.com/arendst/Tasmota - where I just borrowed heavily ;-)

platformio.ini

@@ -9,10 +9,15 @@
 ; https://docs.platformio.org/page/projectconf.html
 
 [platformio]
+default_envs = tbeam
 
-[env:esp32]
+[common]
+; default to a US frequency range, change it as needed for your region and hardware (CN, JP, EU433, EU865)
+hw_version = US
+
+[env]
 platform = espressif32
-board = ttgo-t-beam
+; board = ttgo-t-beam
 ; board = heltec_wifi_lora_32_V2
 framework = arduino
 
@@ -22,14 +27,13 @@ board_build.partitions = partition-table.csv
 
 ; 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 = -Wall -Wextra -Wno-missing-field-initializers -Isrc -Os -Wl,-Map,.pio/build/esp32/output.map -DAXP_DEBUG_PORT=Serial
+build_flags = -Wall -Wextra -Wno-missing-field-initializers -Isrc -Os -Wl,-Map,.pio/build/output.map -DAXP_DEBUG_PORT=Serial -DHW_VERSION_${common.hw_version}
 
 ; not needed included in ttgo-t-beam board file
 ; also to use PSRAM https://docs.platformio.org/en/latest/platforms/espressif32.html#external-ram-psram
 ;  -DBOARD_HAS_PSRAM
 ;  -mfix-esp32-psram-cache-issue
 
-
 ; -DLOG_LOCAL_LEVEL=ESP_LOG_DEBUG -DCORE_DEBUG_LEVEL=ARDUHAL_LOG_LEVEL_DEBUG
 
 upload_speed = 921600
@@ -55,8 +59,6 @@ debug_tool = jlink
 
 debug_init_break = tbreak setup
 
-; Note: some libraries are specified by #ID where there are conflicting library
-; names.
 lib_deps =
   https://github.com/meshtastic/RadioHead.git
   https://github.com/meshtastic/esp8266-oled-ssd1306.git ; ESP8266_SSD1306 
@@ -68,9 +70,12 @@ lib_deps =
   https://github.com/meshtastic/arduino-fsm.git 
   https://github.com/meshtastic/SparkFun_Ublox_Arduino_Library.git
 
-;[env:tbeam] 
-;board = ttgo-t-beam
+[env:tbeam] 
+board = ttgo-t-beam
+lib_deps =
+  ${env.lib_deps}
+  AXP202X_Library
 
-;[env:heltec]
+[env:heltec]
 ;build_type = debug ; to make it possible to step through our jtag debugger 
-;board = heltec_wifi_lora_32_V2
+board = heltec_wifi_lora_32_V2