Intermediate Examples

This section presents some examples of medium complexity that show how to use μPanel with an Arduino UNO board.

2. Using Sliders (2)

In this example Arduino will read in real-time the position of a Slider on the panel and will update both an Analog bar and a 7-segment based display, with 20 Hz of refreshing time.


  • Arduino UNO Board
  • ESP-01 WiFi module (with µPanel Firmware)
  • ADP-01 Breadboard adapter
  • Breadboard wires (4)

µPanel definition 

The panel definition contains the Panel Title, a customised Analog Bar and a Slider. The slider notification interval is set to 50 ms (20 Hz).

D!228;T*15:&#956Panel-Arduino Example 5;{%100,3!88F,228}//L15:0;L25:0;//A1%90-3:0:50:100:!F00;/30R1%90:0:100:1:50:50;

Arduino Code

void setup() {

  Serial.begin(57600);    // Initialise serial
  delay(3000);            // Let's the module start
  // Send Panel discharging old partial messages
  Serial.print("\n$P:D!228;T*15:μ-Arduino Slider 2;{%100,3!88F,228}");

String Msg;

void loop() {
  int c;
  while ((c = > '\n') Msg += (char) c;  // Read incoming chars, if any, until new line
  if (c == '\n')                                       // is message complete?
    Msg.toUpperCase();                                 // Catch partial slider positions too
    if (Msg.substring(0,4).equals("#R1:"))             // has the slider been moved?
        Serial.print("#A1:");                          // Update the Analog bar
        Serial.println(Msg.substring(4));              // with the Slider value 
        int v = (int) Msg.substring(4).toInt();        // Read the Slider position
        int d1 = (v / 10) % 10;                        // Compute the first LCD digit
        int d2 = v % 10;                               // Compute the second LCD digit
        Serial.print("#L1"); Serial.println(d1,DEC);   // Update the first LCD digit
        Serial.print("#L2"); Serial.println(d2,DEC);   // Update the second LCD digit
    Msg = "";