Initial sleep implementation, closes #6

source/main.cpp

@@ -38,6 +38,7 @@
 #include <Adafruit_LittleFS.h>
 #include <InternalFileSystem.h>
 #include "Wire.h"
+#include "sleep.h"
 
 // ─── Boot-loop detection ──────────────────────────────────────────────────────
 #ifdef FEATURE_BOOT_LOOP_DETECT
@@ -241,6 +242,10 @@ void setup() {
   // Seed previous-accel for jerk detection so first frame doesn't spike
   prevAx = imu.readFloatAccelX(); prevAy = imu.readFloatAccelY(); prevAz = imu.readFloatAccelZ();
 
+  // Sleep manager init: must come after calibrateGyroBias() and imu.begin().
+  // Unconditional — sleep.h is always included, no feature flag needed.
+  sleepManagerInit();
+
   bledis.setManufacturer("Seeed Studio");
   bledis.setModel("XIAO nRF52840 Sense");
   bledis.begin();
@@ -289,6 +294,7 @@ void setup() {
   #ifdef FEATURE_PHYSICAL_BUTTONS
     Serial.print(" PHYSBTN");
   #endif
+  Serial.print(" SLEEP");
   Serial.println();
 
   bootStartMs = millis();
@@ -336,6 +342,16 @@ void loop() {
     processPhysicalButtons();
   #endif
 
+  // Sleep manager runs every iteration — must not be gated by LOOP_RATE_MS
+  // because it needs to catch the imuWakeFlag set by the ISR promptly.
+  // Pass idle=false when in IMU_LP (idleFrames is stale since gyro reads
+  // are skipped); the manager tracks its own idle timestamp internally.
+  {
+    bool idle_for_sleep = (sleepStage == SLEEP_IMU_LP) ? true
+                          : (idleFrames >= IDLE_FRAMES);
+    if (sleepManagerUpdate(now, idle_for_sleep, Bluefruit.connected())) return;
+  }
+
   if (now - lastTime < (unsigned long)LOOP_RATE_MS) return;
   float dt = (now - lastTime) / 1000.0f;
   lastTime = now;
@@ -352,7 +368,9 @@ void loop() {
     }
   #endif
 
-  // Gyro reads with optional temperature compensation
+  // Gyro reads with optional temperature compensation.
+  // (sleepManagerUpdate above already returns early when in IMU_LP/DEEP)
+
   float correction = 0.0f;
   #ifdef FEATURE_TEMP_COMPENSATION
     if (cfg.featureFlags & FLAG_TEMP_COMP_ENABLED)
@@ -443,6 +461,8 @@ void loop() {
     }
   #endif
 
+  // (sleep manager already called above, before LOOP_RATE_MS gate)
+
   int8_t  moveX = 0, moveY = 0;
   uint8_t flags = 0;
 
@@ -508,4 +528,4 @@ void loop() {
       }
     }
   #endif
-}
+}