Flush serial buffer after heating

Some hosts like Pronterface use continuous M105 commands to poll temperature, this causes a software halt when the heating via M109 or M190 is finished. Flushing the rx buffer fixes this. As reported in MarlinFirmware#15, thanks to @rug156 for the feedback!
Christoph-D · Jun 1, 2020 · c2226c7 · c2226c7
1 parent 7d82077
commit c2226c7
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
@@ -8751,6 +8751,10 @@ inline void gcode_M109() {
   #if DISABLED(BUSY_WHILE_HEATING)
     KEEPALIVE_STATE(IN_HANDLER);
   #endif
+
+  // flush the serial buffer after heating to prevent lockup by m105
+  flush_and_request_resend();
+
 }
 
 #if HAS_HEATED_BED