Dual-Channel Oscilloscope

// ADC Configuration
#define ADC1_PIN 34
#define ADC2_PIN 35
#define ADC_READ_INTERVAL_US (1000000 / 10000)  // 10 kHz sampling

volatile bool adcStreaming = false;
unsigned long lastAdcMicros = 0;

void loop() {
  // Handle serial commands
  if (Serial.available()) {
    String cmd = Serial.readStringUntil('\n');
    cmd.trim();
    
    if (cmd == "ADC START") {
      adcStreaming = true;
      Serial.println("ADC STREAMING STARTED");
    } 
    else if (cmd == "ADC STOP") {
      adcStreaming = false;
      Serial.println("ADC STREAMING STOPPED");
    }
  }
  
  // Stream ADC samples at 10 kHz
  if (adcStreaming) {
    unsigned long now = micros();
    if (now - lastAdcMicros >= ADC_READ_INTERVAL_US) {
      lastAdcMicros = now;
      
      int adc1 = analogRead(ADC1_PIN);
      int adc2 = analogRead(ADC2_PIN);
      
      // Format: S,<ch1>,<ch2>
      Serial.print("S,");
      Serial.print(adc1);
      Serial.print(",");
      Serial.println(adc2);
    }
  }
}

class SerialWorker(threading.Thread):
    def __init__(self, port, baud, buf1: deque, buf2: deque, signals: Signals):
        super().__init__(daemon=True)
        self.port = port
        self.baud = baud
        self.buf1 = buf1  # Shared buffer for CH1
        self.buf2 = buf2  # Shared buffer for CH2
        self.signals = signals
        self._ser = None
        self._running = False
        self._streaming = False
    
    def run(self):
        self._running = True
        
        try:
            self._ser = serial.Serial(self.port, self.baud, timeout=1)
            time.sleep(1.5)  # Wait for ESP32 reset
            self.signals.connected.emit()
        except Exception as e:
            self.signals.disconnected.emit(str(e))
            return
        
        while self._running:
            try:
                line = self._ser.readline().decode(errors="ignore").strip()
            except Exception as e:
                self.signals.disconnected.emit(str(e))
                break
            
            # Parse sample data: "S,<ch1>,<ch2>"
            if line.startswith("S,"):
                parts = line.split(",")
                if len(parts) == 3:
                    try:
                        v1 = int(parts[1])
                        v2 = int(parts[2])
                        self.buf1.append(v1)
                        self.buf2.append(v2)
                    except:
                        pass

def _update_plot(self):
    n = self._n_samples  # Configurable window size
    
    # Transfer data from thread-safe deques to numpy arrays
    new1 = list(self.buf1)
    new2 = list(self.buf2)
    self.buf1.clear()
    self.buf2.clear()
    
    if new1:
        self.data1 = np.roll(self.data1, -len(new1))
        self.data1[-len(new1):] = new1
    if new2:
        self.data2 = np.roll(self.data2, -len(new2))
        self.data2[-len(new2):] = new2
    
    # Extract visible window
    d1 = self.data1[-n:]
    d2 = self.data2[-n:]
    
    # Convert to time axis (ms)
    t_ms = np.linspace(-(n / SAMPLE_RATE * 1000), 0, n)
    
    # Convert ADC values to voltage
    if self._ymode == 0:  # Voltage mode
        y1 = d1 / ADC_MAX * ADC_VREF
        y2 = d2 / ADC_MAX * ADC_VREF
    else:  # Raw ADC mode
        y1, y2 = d1, d2
    
    # Update plot curves
    if self.chk_ch1.isChecked():
        self.curve1.setData(t_ms, y1)
    
    if self.chk_ch2.isChecked():
        self.curve2.setData(t_ms, y2)