From dd9f70bc99894ac048d55a5ff87e9596a2ded228 Mon Sep 17 00:00:00 2001
From: Jody Bentley <jbentley@whitecars.com>
Date: Wed, 24 Jun 2026 19:15:21 -0400
Subject: [PATCH] ThinkNode M6: run UITask headless to enable status LED,
 button and low-battery shutdown

The M6's two LEDs work in the bootloader and on other firmware, but the
MeshCore companion builds gave no status indication: the red LED (P0.12)
was initialised off and never used, and the blue LED only blinked on
LoRa TX.

The companion status LED, user-button handling and low-battery
auto-shutdown all live in UITask, which is only instantiated when
DISPLAY_CLASS is defined. The M6 is screenless, so UITask never ran and
none of those worked - including AUTO_SHUTDOWN_MILLIVOLTS, which was set
in the env but had no effect.

Run UITask headless via NullDisplayDriver, the same way the other
screenless boards (t1000-e, RAK WisMesh Tag) do, and define
PIN_STATUS_LED. This enables:
 - status LED on the previously-unused red LED (heartbeat, longer blink
   on unread messages); blue keeps its LoRa-TX function
 - the user button (navigation + long-press), groundwork for the
   shutdown request in #2313
 - the already-configured low-battery auto-shutdown (3.3V)

Applied to both companion_radio_ble and companion_radio_usb. The LED
pins/polarity were already correct (RED=12, BLUE=7, active-high), so no
hardware-config change is needed.

Relates to #2313.
---
 variants/thinknode_m6/platformio.ini | 6 ++++++
 variants/thinknode_m6/target.h       | 4 +++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/variants/thinknode_m6/platformio.ini b/variants/thinknode_m6/platformio.ini
index 6fe9043668..72f4167253 100644
--- a/variants/thinknode_m6/platformio.ini
+++ b/variants/thinknode_m6/platformio.ini
@@ -85,12 +85,15 @@ build_flags =
   -D OFFLINE_QUEUE_SIZE=256
   -D AUTO_SHUTDOWN_MILLIVOLTS=3300
   -D QSPIFLASH=1
+  -D DISPLAY_CLASS=NullDisplayDriver
+  -D PIN_STATUS_LED=PIN_LED_RED
 ;  -D MESH_PACKET_LOGGING=1
 ;  -D MESH_DEBUG=1
 build_src_filter = ${ThinkNode_M6.build_src_filter}
   +<helpers/nrf52/SerialBLEInterface.cpp>
   +<helpers/ui/MomentaryButton.cpp>
   +<../examples/companion_radio/*.cpp>
+  +<../examples/companion_radio/ui-new/*.cpp>
 lib_deps =
   ${ThinkNode_M6.lib_deps}
   densaugeo/base64 @ ~1.4.0
@@ -109,10 +112,13 @@ build_flags =
   -D QSPIFLASH=1
   -D OFFLINE_QUEUE_SIZE=256
   -D AUTO_SHUTDOWN_MILLIVOLTS=3300
+  -D DISPLAY_CLASS=NullDisplayDriver
+  -D PIN_STATUS_LED=PIN_LED_RED
 build_src_filter = ${ThinkNode_M6.build_src_filter}
   +<helpers/ui/buzzer.cpp>
   +<helpers/ui/MomentaryButton.cpp>
   +<../examples/companion_radio/*.cpp>
+  +<../examples/companion_radio/ui-new/*.cpp>
 lib_deps =
   ${ThinkNode_M6.lib_deps}
   densaugeo/base64 @ ~1.4.0
diff --git a/variants/thinknode_m6/target.h b/variants/thinknode_m6/target.h
index 76188e584e..07ff322947 100644
--- a/variants/thinknode_m6/target.h
+++ b/variants/thinknode_m6/target.h
@@ -10,7 +10,9 @@
 #include <helpers/sensors/EnvironmentSensorManager.h>
 #include <helpers/sensors/LocationProvider.h>
 #ifdef DISPLAY_CLASS
-  #include <helpers/ui/GxEPDDisplay.h>
+  // The M6 is screenless; DISPLAY_CLASS=NullDisplayDriver is used only to run
+  // UITask headless so the status LED (PIN_STATUS_LED) and button work.
+  #include <helpers/ui/NullDisplayDriver.h>
   #include <helpers/ui/MomentaryButton.h>
 #endif