diff -r fc55f6eaa8bc -r c146d19101a3 src/hp34comm.h
--- a/src/hp34comm.h	Sat Nov 07 19:24:11 2020 +0100
+++ b/src/hp34comm.h	Mon Nov 09 23:05:24 2020 +0100
@@ -33,6 +33,8 @@
   void startup(uint8_t keycode=0xFF);
   void sendkey(uint8_t keycode);
   void send_key_when_idle();
+  void send_startup_seq();
+  void send_startup_seq(uint8_t keycode);
 
 private:
   void pushCmd(uint8_t cmd, uint8_t size, char *payload);
@@ -54,6 +56,11 @@
   unsigned int errs[MAX_ERRS];
   Ticker timeouter;
 
+  Thread send_thread;
+  void send_pending_key();
+  bool wait_for(uint8_t);
+
+
  public:
   // global state machine
   typedef enum {