- Allow other scripts / inputs to control AP heading too

- Fix failure if rp2040_hid is connected above 32767 feet

FlyWithLua/rpi2040_hid.lua

@@ -130,6 +130,8 @@ else
    send_app_report(device, math.floor(ap_hdg + 0.5), build_leds(), math.floor(ap_alt + 0.5), -2, -2, status_machmode == 1)
    local prev_status_altmode = 0
    local prev_status_machmode = status_machmode
+   local prev_ap_hdg = ap_hdg
+   local prev_report_ap_hdg = 0
    function usb_app()
       local send_hdg = -1
       local send_alt = -1
@@ -157,9 +159,15 @@ else
 	 mag_hdg_int = math.floor(mag_hdg + 0.5)
 	 ap_hdg = mag_hdg_int
 	 send_hdg = mag_hdg_int
-      elseif app_report_good and app_report[1] ~= 0xffff then
+      elseif prev_ap_hdg ~= ap_hdg then
+	 send_hdg = ap_hdg
+      elseif app_report_good and app_report[1] ~= 0xffff and prev_report_ap_hdg ~= app_report[1] then
 	 ap_hdg = app_report[1]
       end
+      prev_ap_hdg = ap_hdg
+      if app_report_good and app_report[1] ~= 0xffff then
+	 prev_report_ap_hdg = app_report[1]
+      end
       -- autopilot altitude
       if button(button_offset + button_alt_sync) and not last_button(button_offset + button_alt_sync) then
 	 cur_alt_int = math.floor(cur_alt + 0.5)
@@ -213,4 +221,10 @@ else
    end
 
    do_every_frame("usb_app()")
+
+   function exit_handler()
+      send_app_report(device, -2, 0, -2, -2, -2, 0)
+   end
+
+   do_on_exit('exit_handler()')
 end