Merge remote-tracking branch 'OptoTest/master'

# Conflicts:
#	OpticalChannelTester/App.cpp

OpticalChannelTester/App.h

@@ -24,6 +24,7 @@ class App {
   void changeMenu(int direction);
   void sanitizeRange();
   void startTest();
+  bool armSlave();
   bool prepareStage();
   bool startLocalMeasurement(float hz, float duty);
   void startMasterDiscovery();
@@ -39,6 +40,7 @@ class App {
   uint64_t actualNominalTotalUs();
   ProtocolPacket makePacket(MessageType type) const;
   void sendCurrent(MessageType type);
+  void updateHeartbeat();
   bool packetForCurrent(const ProtocolPacket &p) const;
 
   Button startButton_, modeButton_;
@@ -61,8 +63,10 @@ class App {
   uint8_t peer_[6] = {};
   bool havePeer_ = false;
   uint32_t deadlineMs_ = 0, lastSendMs_ = 0;
+  uint32_t lastHeartbeatMs_ = 0, lastPeerSeenMs_ = 0;
   uint8_t retries_ = 0;
   ProtocolPacket pendingPacket_ = {};
   bool initialized_ = false, bootResetCandidate_ = false;
   uint32_t bootCheckStartedMs_ = 0;
+  uint32_t slaveRearmAtMs_ = 0;
 };