move button check and new mode check before loop

cubesatsim/cubesatsim.ino

@@ -283,25 +283,18 @@ void loop() {
   else
       Serial.println("Unknown mode!");
 	
-//  while ((millis() - sampleTime) < ((unsigned int)samplePeriod)) // - 250))  // was 250 100
-  while ((millis() - sampleTime) < ((unsigned int)frameTime)) // - 250))  // was 250 100
-    sleep(0.01); // was 0.1 sec
-  sampleTime = (unsigned int) millis();	  
+  serial_input();  
 	
-//  delay(2000);
-//  test_radio();
-
-  if ((mode == FSK) || (mode == BPSK)) {
-//	  if (!wifi) 
-	    digitalWrite(LED_BUILTIN, LOW);	
-	  digitalWrite(MAIN_LED_BLUE, LOW);
-
-	//  delay(3000);	
-	  sleep(0.2); // 2.845); // 3.0);
-
-//	  if (!wifi) 
-	   	  digitalWrite(LED_BUILTIN, HIGH);
-	  digitalWrite(MAIN_LED_BLUE, HIGH);
+// check for button press 
+  if (digitalRead(MAIN_PB_PIN) == PRESSED) // pushbutton is pressed
+      process_pushbutton();
+  if (BOOTSEL)	  // boot selector button is pressed on Pico
+      process_bootsel();
+	
+  if (prompt) {
+//    Serial.println("Need to prompt for input!");
+    prompt_for_input();	  
+    prompt = false;	  
   }
 	
   // check to see if the mode has changed
@@ -319,20 +312,27 @@ void loop() {
     config_telem();
     config_radio();
     sampleTime = (unsigned int) millis();	 	 
- }
-
-  serial_input();  
+ }	
 	
-// check for button press 
-  if (digitalRead(MAIN_PB_PIN) == PRESSED) // pushbutton is pressed
-      process_pushbutton();
-  if (BOOTSEL)	  // boot selector button is pressed on Pico
-      process_bootsel();
+//  while ((millis() - sampleTime) < ((unsigned int)samplePeriod)) // - 250))  // was 250 100
+  while ((millis() - sampleTime) < ((unsigned int)frameTime)) // - 250))  // was 250 100
+    sleep(0.01); // was 0.1 sec
+  sampleTime = (unsigned int) millis();	  
 	
-  if (prompt) {
-//    Serial.println("Need to prompt for input!");
-    prompt_for_input();	  
-    prompt = false;	  
+//  delay(2000);
+//  test_radio();
+
+  if ((mode == FSK) || (mode == BPSK)) {
+//	  if (!wifi) 
+	    digitalWrite(LED_BUILTIN, LOW);	
+	  digitalWrite(MAIN_LED_BLUE, LOW);
+
+	//  delay(3000);	
+	  sleep(0.2); // 2.845); // 3.0);
+
+//	  if (!wifi) 
+	   	  digitalWrite(LED_BUILTIN, HIGH);
+	  digitalWrite(MAIN_LED_BLUE, HIGH);
   }
 	
   //  Calculate loop time