refactored handling of settings '$' command out of gcode module and into settings module

settings.c

@@ -25,6 +25,7 @@
 #include "eeprom.h"
 #include "wiring_serial.h"
 #include <avr/pgmspace.h>
+#include "protocol.h"
 
 settings_t settings;
 
@@ -81,6 +82,28 @@ void settings_dump() {
   printPgmString(PSTR("\r\n'$x=value' to set parameter or just '$' to dump current settings\r\n"));
 }
 
+// Parameter lines are on the form '$4=374.3' or '$' to dump current settings
+uint8_t settings_execute_line(char *line) {
+  uint8_t char_counter = 1;
+  double parameter, value;
+  if(line[0] != '$') { 
+    return(STATUS_UNSUPPORTED_STATEMENT); 
+  }
+  if(line[char_counter] == 0) { 
+    settings_dump(); return(STATUS_OK); 
+  }
+  read_double(line, &char_counter, &parameter);
+  if(line[char_counter++] != '=') { 
+    return(STATUS_UNSUPPORTED_STATEMENT); 
+  }
+  read_double(line, &char_counter, &value);
+  if(line[char_counter] != 0) { 
+    return(STATUS_UNSUPPORTED_STATEMENT); 
+  }
+  settings_store_setting(parameter, value);
+  return(STATUS_OK);
+}
+
 void write_settings() {
   eeprom_put_char(0, SETTINGS_VERSION);
   memcpy_to_eeprom_with_checksum(1, (char*)&settings, sizeof(settings_t));