From fe44cb432634b2cd97b9a470d3f4ca7bd6b4b269 Mon Sep 17 00:00:00 2001
From: Kevin Le <vinhdat82@gmail.com>
Date: Sat, 17 Oct 2026 12:04:21 +0700
Subject: [PATCH] Custom GPS, Added BME680_BSEC and Keep time across reset for
 RAK3401

---
 variants/rak3401/fix_bsec_lib.py | 15 +++++++++++++++
 variants/rak3401/platformio.ini  | 19 +++++++++++++++++++
 2 files changed, 34 insertions(+)
 create mode 100644 variants/rak3401/fix_bsec_lib.py

diff --git a/variants/rak3401/fix_bsec_lib.py b/variants/rak3401/fix_bsec_lib.py
new file mode 100644
index 000000000..605ff1187
--- /dev/null
+++ b/variants/rak3401/fix_bsec_lib.py
@@ -0,0 +1,15 @@
+Import('env')
+import os
+
+# Bosch has a goof in their PlatformIO packaging making linking fail.
+# The BSEC library's extra_script.py selects cortex-m4/libalgobsec.a (soft-float ABI).
+# nRF52840 compiles with -mfloat-abi=hard, requiring the fpv4-sp-d16-hard blob.
+# Workaround to prepend the hard-float path so the linker finds it before the 
+# soft-float one.
+bsec_hard = os.path.join(
+    env.subst('$PROJECT_DIR'),
+    '.pio', 'libdeps', env.subst('$PIOENV'),
+    'BSEC Software Library', 'src',
+    'cortex-m4', 'fpv4-sp-d16-hard'
+)
+env.Prepend(LIBPATH=[bsec_hard])
\ No newline at end of file
diff --git a/variants/rak3401/platformio.ini b/variants/rak3401/platformio.ini
index d157e4b1d..eddadd031 100644
--- a/variants/rak3401/platformio.ini
+++ b/variants/rak3401/platformio.ini
@@ -2,6 +2,9 @@
 extends = nrf52_base
 board = rak3401
 board_check = true
+board_build.ldscript = boards/nrf52840_s140_v6.ld
+extra_scripts = ${nrf52_base.extra_scripts}
+  post:variants/rak3401/fix_bsec_lib.py
 build_flags = ${nrf52_base.build_flags}
   ${sensor_base.build_flags}
   -I variants/rak3401
@@ -13,6 +16,11 @@ build_flags = ${nrf52_base.build_flags}
   -D SX126X_CURRENT_LIMIT=140
   -D SX126X_RX_BOOSTED_GAIN=1
   -D SX126X_REGISTER_PATCH=1       ; Patch register 0x8B5 for improved RX with SKY66122 FEM
+  -D FORCE_GPS_ALIVE               ; on RAK3401, gpsResetPin ends up = WB_IO2 (kills 3V3_S rail) or
+                                   ; pin 4 (= SX126X_RESET, holds radio in reset). stop_gps() must not run.
+  -D PIN_GPS_EN=-1                 ; -1 = no dedicated GPS enable pin (power is the shared 3V3_S rail), same as rak4631
+  -UENV_INCLUDE_BME680
+  -D ENV_INCLUDE_BME680_BSEC=1
 build_src_filter = ${nrf52_base.build_src_filter}
   +<../variants/rak3401>
   +<helpers/sensors>
@@ -40,6 +48,17 @@ build_src_filter = ${rak3401.build_src_filter}
   +<helpers/ui/SSD1306Display.cpp>
   +<../examples/simple_repeater>
 
+[env:RAK_3401_repeater_bridge_rs232_serial1]
+extends = env:RAK_3401_repeater
+build_flags =
+  ${env:RAK_3401_repeater.build_flags}
+  -D ADVERT_NAME='"RAK3401 1W RS232 Bridge"'
+  -D WITH_RS232_BRIDGE=Serial1
+  -D WITH_RS232_BRIDGE_RX=PIN_SERIAL1_RX
+  -D WITH_RS232_BRIDGE_TX=PIN_SERIAL1_TX
+build_src_filter = ${env:RAK_3401_repeater.build_src_filter}
+  +<helpers/bridges/RS232Bridge.cpp>
+
 [env:RAK_3401_room_server]
 extends = rak3401
 build_flags =