   myTympan.println(input_gain_dB); //print text to Serial port for debugging
   myTympan.print("Digital Gain (dB) = "); 
   myTympan.println(digital_gain_dB); //print text to Serial port for debugging
+void setButtonText(String btnId, String text) {
+  myTympan.println("TEXT=BTN:" + btnId + ":"+text);
 }
+
+}
    case 'k':
      changeGain(3.0);
      printGainLevels();
      break;
    case 'K':
      changeGain(-3.0);
      printGainLevels();
      break;
  }
}


  //Add first page to GUI
  page_h = myGUI.addPage("MyFirstPage");
      //Add a card under the first page
      card_h = page_h->addCard("Change Loudness");
          //Add a "-" digital gain button with the Label("-"); Command("K"); Internal ID ("minusButton"); and width (4)
          card_h->addButton("-","K","minusButton",4);  //displayed string, command, button ID, button width (out of 12)

          //Add an indicator that's a button with no command:  Label (value of the digital gain); Command (""); Internal ID ("gain indicator"); width (4).
          card_h->addButton(String(digital_gain_dB),"","gainIndicator",4);  //displayed string (blank), command (blank), button ID, button width (out of 12)
  
          //Add a "+" digital gain button with the Label("+"); Command("K"); Internal ID ("minusButton"); and width (4)
          card_h->addButton("+","k","plusButton",4);   //displayed string, command, button ID, button width (out of 12)
        
  //add some pre-defined pages to the GUI
  myGUI.addPredefinedPage("serialMonitor");
  myGUI.addPredefinedPage("serialPlotter");
}


